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Cheung, Kai-him Matthew, and 張啟謙. "Bioremediation of toxic metals." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/194562.
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Traditional remediation techniques in removing toxic metal contaminants using physical and chemical methods are expensive and may cause other forms of damage to the environment, comparing with these techniques bioremediation can serve as an inexpensive, effective and environmental friendly remediation method. This thesis mainly discusses different bioremediation techniques and identifies possible areas in Hong Kong for bioremediation and suggests bioremediation methods for each potential area. Bioremediation of toxic metals is the use of microorganisms, plants, or even larger sized organisms to decontaminate sites with toxic metals.
Bioremediation includes phytoremediation, microremediation and vermiremediation which use plants, microorganisms and earthworms to remediate contaminated environments respectively. The 4 most common mechanisms in phytoremediation of toxic metals are phytoextraction, phytofiltration, phytovolatilization and phytostabilization. Phytoremediation are used frequently for remediation around the world and its development includes using well-understood technology and genetic engineering to increase its effectiveness. Microremediation is another promising technology in bioremediation of toxic metals and consists of 6 major mechanisms which are biosorption, bioaccumulation, biotransformation, bioleaching, biomineralization and microbially-enhanced chemisorption of metals.
Microremediation is mainly in research phase and its development includes identifying new species, combining with phytoremediation and genetic engineering. Vermiremediation is another rapidly developing technique in bioremediation of toxic metals, assisting other bioremediation by burrowing actions of earthworms and its excretion, and accumulating toxic metals inside their bodies. Vermiremediation is also in research phase but it is rapidly developing. Generally, bioremediation is around 60% cheaper than traditional remediation methods and no pollutants are emitted during the process. However the remediation process is slow and generally takes longer than a year. Sources of toxic metals in contaminated areas in Hong Kong are mainly due to historic industrial discharge although present activities also contribute. Potential areas include sites for electronic waste activities, sediments of Kwun Tong typhoon shelter and sediments of Tolo Harbour.<br>published_or_final_version<br>Environmental Management<br>Master<br>Master of Science in Environmental Management
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Sekhula, Koena Sinah. "Heavy metal ion resistance and bioremediation capacities of bacterial strains isolated from an Antimony Mine." Thesis, University of Limpopo, 2005. http://hdl.handle.net/10386/139.
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Thesis (M.Sc.) -- University of Limpopo, 2005<br>Six aerobic bacterial strains [GM 10(1), GM 10 (2), GM 14, GM 15, GM 16 and
GM 17] were isolated from an antimony mine in South Africa. Heavy-metal
resistance and biosorptive capacities of the isolates were studied. Three of the
isolates (GM 15, GM 16 and GM 17) showed different degrees of resistance to
antimony and arsenic oxyanions in TYG media. The most resistant isolate GM 16
showed 90 % resistance, followed by GM 17 showing 60 % resistance and GM
15 was least resistant showing 58 % resistance to 80 mM arsenate (AsO4
3-). GM
15 also showed 90 % resistance whereas isolates GM 16 and GM 17 showed 80
% and 45 % resistance respectively to 20 mM antimonate (SbO4
3-). Arsenite
(AsO2
-) was the most toxic oxyanion to all the isolates.
Media composition influenced the degrees of resistance of the isolates to some
divalent metal ions (Zn2+, Ni2+, Co2+, Cu2+ and Cd2+). Higher resistances were
found in MH than in TYG media. All the isolates could tolerate up to 5 mM of the
divalent metal ions in MH media, but in TYG media, they could only survive at
concentrations below 1 mM. Also, from the toxicity studies, high MICs were
observed in MH media than TRIS-buffered mineral salt media. Zn2+ was the most
tolerated metal by all the isolates while Co2+ was toxic to the isolates.
The biosorptive capacities of the isolates were studied in MH medium containing
different concentrations of the metal ions, and the residual metal ions were
determined using atomic absorption spectroscopy. GM 16 was effective in the
removal of Cu2+ and Cd2+ from the contaminated medium. It was capable of
removing 65 % of Cu2+ and 48 % of Cd2+ when the initial concentrations were
100 mg/l, whereas GM 15 was found to be effective in the biosorption of Ni2+
from the aqueous solutions. It was capable of removing 44 % of Ni2+ when the
initial concentration was 50 mg/l. GM 17 could only remove 20 % of Cu2+ or Cd2+.
These observations indicated that GM 16 could be used for bioremediation of
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Cu2+ and Cd2+ ions from Cu2+ and Cd2+-contaminated aqueous environment,
whereas GM 15 could be used for bioremediation of Ni2+.<br>National Research Foundation and the University of the North Research Unit
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Wasay, Syed A. "Bioremediation of soils polluted by heavy metals using organic acids." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0017/NQ44624.pdf.
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Westwater, John. "Regulation of GSH1 expression by oxidants and heavy metals in Saccharomyces cerevisiae." Thesis, Heriot-Watt University, 2000. http://hdl.handle.net/10399/518.
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Tsang, Kar Wing. "Microbial mobilization of hazardous metals and bioremediation of water and soils /." The Ohio State University, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487842372895011.
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Rahman, Aminur. "Bioremediation of Toxic Metals for Protecting Human Health and the Ecosystem." Doctoral thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-51436.
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Heavy metal pollutants, discharged into the ecosystem as waste by anthropogenic activities, contaminate drinking water for millions of people and animals in many regions of the world. Long term exposure to these metals, leads to several lethal diseases like cancer, keratosis, gangrene, diabetes, cardio- vascular disorders, etc. Therefore, removal of these pollutants from soil, water and environment is of great importance for human welfare. One of the possible eco-friendly solutions to this problem is the use of microorganisms that can accumulate the heavy metals from the contaminated sources, hence reducing the pollutant contents to a safe level. In this thesis an arsenic resistant bacterium Lysinibacillus sphaericus B1-CDA, a chromium resistant bacterium Enterobacter cloacae B2-DHA and a nickel resistant bacterium Lysinibacillus sp. BA2 were isolated and studied. The minimum inhibitory concentration values of these isolates are 500 mM sodium arsenate, 5.5 mM potassium chromate and 9 mM nickel chloride, respectively. The time of flight-secondary ion mass spectrometry and inductively coupled plasma-mass spectroscopy analyses revealed that after 120 h of exposure, the intracellular accumulation of arsenic in B1-CDA and chromium in B2-DHA were 5.0 mg/g dwt and 320 μg/g dwt of cell biomass, respectively. However, the arsenic and chromium contents in the liquid medium were reduced to 50% and 81%, respectively. The adsorption values of BA2 when exposed to nickel for 6 h were 238.04 mg of Ni(II) per gram of dead biomass indicating BA2 can reduce nickel content in the solution to 53.89%. Scanning electron micrograph depicted the effect of these metals on cellular morphology of the isolates. The genetic composition of B1-CDA and B2-DHA were studied in detail by sequencing of whole genomes. All genes of B1-CDA and B2-DHA predicted to be associated with resistance to heavy metals were annotated. The findings in this study accentuate the significance of these bacteria in removing toxic metals from the contaminated sources. The genetic mechanisms of these isolates in absorbing and thus removing toxic metals could be used as vehicles to cope with metal toxicity of the contaminated effluents discharged to the nature by industries and other human activities.
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Payne, Rosemary Anne. "Spirulina as a bioremediation agent : interaction with metals and involvement of carbonic anhydrase." Thesis, Rhodes University, 2000. http://hdl.handle.net/10962/d1003968.
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Heavy metal contamination from mining and other industrial operations is becoming an increasing problem with regards to the depleting water resources in South Africa. This study involved the investigation of the use of an algal biomass as a possible alternative to the traditional chemical means of removing these metals. When the toxic effects of metals were investigated, Spirulina was found to have a threshold level of about 30 μM for copper, zinc and lead. Copper and zinc appeared to have a direct effect on the photosynthetic pathway, thereby causing a rapid decline in cell growth. Lead on the other hand seemed to affect surface properties and hence took longer to cause deterioration in growth. Although relatively low concentrations of metal may have a toxic effect on the cyanobacterium, Spirulina may have potential as a precipitation agent. The role of Spirulina in the precipitation of heavy metals appears to be through its ability to maintain a high pH in the surrounding medium, possibly through the enzyme carbonic anhydrase. Subsequent studies therefore focused on the assay and isolation of this enzyme. Two different radiotracer assays, in which carbonic anhydrase converts radiolabelled bicarbonate to carbon dioxide, were investigated, but were found to have several problems. Results were insensitive and could not be reproduced. The standard Wilbur-Anderson method subsequently investigated also proved to be insensitive with a tremendous degree of variability. Although not quantitative, SDS-PAGE proved to be the most reliable method of detection, and was therefore used in subsequent procedures. Chlamydomonas reinhardtii was the subject of initial enzyme isolation studies as these procedures are well documented. Although the published protocols proved unsuccessful, affinity chromatography of a membrane stock solution from Chlamydomonas reinhardtii yielded two relatively pure protein bands. These bands were presumed to represent two subunits of carbonic anhydrase, although Western blot analysis would be required to confirm their identity. Purification of carbonic anhydrase from Spirulina, however, proved unsuccessful and results obtained were very inconclusive. Hence, further analysis of Spirulina is required. The possibility of cloning CA from a genomic library was also considered, but suitable primers could not be designed from the aligned sequences.
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Salami, Indah Rachmatiah Siti. "Investigation into remediation of contaminated soil containing high sulphate and heavy metals concentration." Thesis, University of Newcastle Upon Tyne, 1999. http://hdl.handle.net/10443/630.
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This study involved the investigation of a contaminated soil problem in Gateshead, UK. The site was previously a dumping area from industrial activities for over a hundred years and generated problems of high sulphate concentration and heavy metals in both the soil and the leachate which discharges into the River Tyne. The combination of such contaminants has not been widely investigated in the area of contaminated soil. The study was therefore divided into 2 parts, namely bioremediation of the contaminated soil and leachate treatment by reverse osmosis. The bioremediation study involved treatability tests which included slurry, microbial growth and column tests. The reverse osmosis study involved membrane fouling and leachate pre-treatment experiments. The bioremediation study stimulated the indigenous microorganisms by the addition of nutrients and carbon sources. The soil slurry and microbial growth tests determined the combination of nitrogen and phosphorus required to produce higher C02 evolution as an assessment of microbial activity. It was found in the column tests that the addition of a carbon source and appiopriate nutrient combinations resulted in a significant reduction of sulphate in both the leachate and the soil matrix. Furthermore, this was also accompanied by an increase in the microbial population in the soil matrix. It was also considered that- assimilatory sulphate reduction by microorganisms had taken place since H2S production could not be detected in the open system of the column. However, the high pH of the soil that was higher than 8 possibly caused H2S production undetected in this study. Zinc, manganesea nd copper,i n contrastw ere not reducedi n the soil matrix. Only arsenic showed significant reduction in the soil columns. Heavy metals were precipitateda nd were still presenti n high concentrationsin the leachatea nd would require further treatmenti n the liquid phase.T his was demonstratedb y the study of the use of a LPROM (Low PressureR everseO smosisM embrane)t o treat leachate from the contaminated soil. The reverse osmosis study showed that zinc and arsenic could be reduced by up to 86% and 97% respectively. Sulphate was also satisfactorily reduced up to 99%. However, the study on membrane fouling confirmed that the sulphate concentration was the main effect of fouling. Ferric chloride, aluminium sulphate, barium chloride and polyelectrolyte Zetag 92 were used for coagulation-flocculation in the pretreatment of the leachate. The study revealed that the sulphate concentration could only be reduced at the most by 43% using a FeC13, BaC12 and Zetag 92 combination. FeC13 showed better floc characteristics than alum whereas BaC12 improved sulphate removal but increased the turbidity in the supernatants. However, the use of BaC12 would significantly increase the cost of pretreatment. The study recommended a further investigation into the use of a range of readily available carbon, nitrogen and phosphorous sources in the soil column or at pilot-scale for designing a full-scale bioremediation system. Meanwhile, an investigation into other leachate pretreatment methods such as continuous microfiltration or anti-scalant addition was also suggested.
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Turpeinen, Riina. "Interactions between metals, microbes and plants : bioremediation of arsenic and lead contaminated soils." Helsinki : University of Helsinki, 2002. http://ethesis.helsinki.fi/julkaisut/mat/ekolo/vk/turpeinen/.
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Pretorius, Travers. "Bioremediation of Contaminated Soils by Echinacea purpurea and Arbuscular Mycorrhizal Fungi." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32500.
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As a potential bioremediation system for contaminated soils, I evaluated the use of an arbuscular mycorrhizal (AM) fungus, Glomus intraradices on roots and shoots uptake of polycyclic aromatic hydrocarbons (PAHs), alkyl PAHs, and toxic metals in Echinacea purpurea, in using a controlled 20-week greenhouse study and a complimentary 2-year field study. E. purpurea seeds were either inoculated with the mycorrhizal fungus (AM) or not inoculated (non-AM) and grown in soil provided by the National Capital Commission (NCC) that have known contamination.
In the greenhouse study, AM inoculation increased the uptake of alkyl PAHs in the roots of E. purpurea. The AM inoculation showed no effect on root uptake of PAHs and toxic metals over the 20-week study period. However, when I calculated the uptake rates (k1) for PAHs between both treatments, the AM treated roots ha 10-fold higher k1 values than non-AM treated roots. The soil concentrations of PAHs were found to increase over time with AM inoculation, suggesting, that AM fungi are causing a solvent depletion through root uptake of minerals and carbon, which concentrates the more hydrophobic PAHs in soils. Alkyl PAHs and metals showed no change over time amongst any of the treatments.
Assessing the performance of AM fungi on the uptake of contaminants under field conditions, only PAHs showed increased bioaccumulation in the shoots of E. purpurea with AM inoculation. Alkyl PAHs and metals in plant material were unaffected by the AM inoculation, but increased significantly from year 1 to year 2. The uptake rates among treatments were similar, with non-AM roots having slightly greater uptake. Soil concentrations of PAHs and alkyl PAHs were unaffected over the course of the experiment. Our control soil, however, showed significant increases in concentration from year 1 to year 2 with alkyl PAHs.
These results quantified the influence of AM hyphae-mediated uptake of organic and inorganic contaminant transfer from soil to plants and the bioaccumulation kinetics for contaminants by E. purpurea that will be useful for environmental models and phytoremediation strategies.
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Giansante, Ruth Helena. "Potencial de Rizobactérias para a Remoção de Cádmio em Solução." Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/153351.
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Previous issue date: 2017-11-27<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)<br>Rizobactérias são excelentes candidatas à aplicação em processos de bioacumulação de elementos potencialmente tóxicos, pois desenvolveram mecanismos para a incorporação intracelular de uma ampla gama de íons. A sensibilidade e a capacidade de remoção de cádmio (Cd2+) de duas espécies de rizobactérias: Rizobium tropici (LBMP-C01) e Ensifer meliloti (LBMPC02), foram estudadas. A concentração mínima inibitória (CMI) das bactérias foi determinada pelo cultivo em meio contendo CdCl2.2H2O (0,025 a 4 mmol L-1). Foram realizados testes de viabilidade das células das duas estirpes na CMI e ensaios de bioacumulação com suspensões de células bacterianas nas doses de 10, 20 e 30 %(v/v) em solução contendo 100 mg L-1 de Cd2+. As estirpes LBMP-C01 e LBMP-C02 foram sensíveis a concentrações de Cd2+ superiores a 1,0 e 0,05 mmol L-1, respectivamente. As células de LBMP-C01 e LBMP-C02 apresentaram-se viáveis nas CMI 1,0 e 0,05 mmol L-1 Cd2+, respectivamente. A estirpe LBMP-C01 não removeu Cd2+ nos ensaios de bioacumulação e a estirpe LBMP-C02 foi capaz de remover 80 % deste íon em solução contendo 100 mg L-1 Cd2+, após 72 h de contato e 30 %(v/v) do bioacumulador. Os espectros de absorção molecular na região do infravermelho, de ambas as espécies estudadas praticamente não indicaram diferenças nos grupos funcionais presentes nas moléculas da biomassa celular. A observação por microscopia eletrônica de transmissão mostrou a presença de maior número de grânulos eletrodensos no citoplasma da estirpe de LBMP-C02 em relação à LBMP-C01 quando estas foram cultivadas com Cd2+. A estirpe LBMP-C02 foi a mais eficiente na remoção de Cd2+. A resistência a metais dessas duas bactérias envolve mecanismos diferentes.<br>Rhizobacteria are excellent candidates for use in the processes of bioaccumulation of potentially toxic elements because they have developed mechanisms for the intracellular uptake of a wide range of ions. Here, the sensitivity and capacity to remove cadmium (Cd2+) of two species of rhizobacteria, Rhizobium tropici (LBMP-C01) and Ensifer meliloti (LBMP-C02), were studied. The minimum inhibitory concentration (MIC) of the bacteria was determined by culturing them in medium containing CdCl2·2H2O (0.025 to 4 mmol L-1 ). Cell viability tests of the two strains were performed at MIC, and bioaccumulation assays were performed with 10, 20, and 30 %(v/v) bacterial cell suspensions in a Cd2+ solution 100 mg L-1 . Strains LBMP-C01 and LBMP-C02 were sensitive to Cd2+ concentrations above 1.0 and 0.05 mmol L-1 , respectively. LBMP-C01 and LBMP-C02 cells were viable at the MICs of Cd2+ solution 1.0 and 0.05 mmol L-1 , respectively. LBMP-C01 did not remove Cd2+ in the bioaccumulation assays, whereas LBMP-C02 removed 80 % of this ion in Cd2+ solution 100 mg L-1 , after 72 h of contact and 30 %(v/v) of the bioaccumulator. The infrared absorption spectra of both species did not indicate differences in the functional groups present in the molecules of the cell biomass. Transmission electron microscopy showed the presence of a larger number of electron-dense granules in the cytoplasm of LBMP-C02 compared to LBMP-C01 when they were cultured with Cd2+. The LBMP-C02 strain was the most efficient in the Cd2+ removal. The metal resistance of these two bacteria involves different mechanisms.
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Patel, Jigar J. "Genetic engineering of S-layer of Caulobacter crescentus for bioremediation of heavy metals." Bowling Green, Ohio : Bowling Green State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=bgsu1257191921.
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Shumba, Trust. "Removal of heavy metals from CRUD and slime dam material using soil washing and bioremediation." Thesis, Link to the online version, 2008. http://hdl.handle.net/10019/1536.
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Ringbauer, Joseph A. "Hydrogenases of Desulfovibrio desulfuricans G20 /." free to MU campus, to others for purchase, 2000. http://wwwlib.umi.com/cr/mo/fullcit?p9998516.
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Kamika, I., and MNB Momba. "Assessing the resistance and bioremediation ability of selected bacterial and protozoan species to heavy metals in metal-rich industrial wastewater." Microbiology, 2013. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000528.
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Heavy-metals exert considerable stress on the environment worldwide. This study assessed the resistance to and bioremediation of heavy-metals by selected protozoan and bacterial species in highly polluted industrial-wastewater. Specific variables (i.e. chemical oxygen demand, pH, dissolved oxygen) and the growth/dieoff- rates of test organisms were measured using standard methods. Heavy-metal removals were determined in biomass and supernatant by the Inductively Couple Plasma Optical Emission Spectrometer. A parallel experiment was performed with dead microbial cells to assess the biosorption ability of test isolates.
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Stoll, Anita. "Bioaccumulation of heavy metals by the yeast S. cerevisiae and the bioremediation of industrial waste water." Thesis, Rhodes University, 1997. http://hdl.handle.net/10962/d1004075.
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Water is an essential element in all aspects of life and is vital for both domestic and industrial purposes regarding both the quality and quantity thereof. Similar to many other drought stricken countries, South Africa requires water for the socio-economic growth of the country, yet is faced with the problem of maintaining the quality of its drinking water as well as protecting the dwindling supplies. In an attempt to prevent the deterioration of South African water supplies the treatment, purification and recycling of industrial and mining waste water has recently become of prime importance. Many industrial and mining waste waters contain heavy metals in toxic quantities. The conventional processes that have been used till recently to address this problem, are often expensive or contain chemical agents which compound the environmental problem. As an alternative biological methods of metal accumulation appear to offer an economic and efficient alternative to these methods. An advantage to the South African scenario is the commercial production of the yeast, S. cerevisiae as a readily inexpensive by-product from some fermentation industries, Yeast cells, and in particular S. cerevisiae have proven to be capable of accumulating heavy metals, and therefore exhibit potential application in the bioremediation of waste water. The aim of this project was twofold. The initial part of this work attempted to define the mechanisms of metal accumulation by the yeast cells and cellular components. The information obtained from these initial studies provided a data base required for the development of a bioremediation system. Initial contact with the metal ions occurs at the wall interface of the yeast cell. Metal accumulation appears to be a function of all the cell wall components. The isolated cell wall components are better metal chelators then the intact cell walls. An apparent affinity series of mannan > chitin> glucan > intact cell walls exists. However, these components differ in their affinities for metal ions. Storage of metal ions within the cell occurs predominantly in the vacuole. The present study concluded that metal accumulation by the vacuole could be related to size. Metal accumulation occurred in the order of Cu2+ > Co2+ > Cd2+ with a corresponding decrease in atomic radii of Cd2+ > C02+ > Cu2+. Vacuolar ion deposition occurs at an early stage during the internalization of metal ions within the yeast cells. At the onset of vacuolar saturation, depositions of metal ions as granules within the cytosol occurs. In the presence of heavy metal cations viable yeast cells can be shown to exhibit two types of cellular responses. Uptake of Cu2+ and Cd2+ causes the loss of intracellular physiological cations from within the yeast cell. In comparison, uptake of Co2+ into the cell does not have this effect. All three heavy metal cations initiate plasma cell membrane permeability, thus the Cu2+ and Cd2+ induced loss of the intracellular cations, occurs. ~ a result of ion-exchange mechanisms and not due to cation leakage brought about by membrane permeabilization. Uptake of heavy metals by viable yeasts appears to be generally non-selective though the amount of metals accumulated are largely affected by the ratio of ambient metal concentration to biomass quantity. In addition, the energy dependent nature of internalization necessitates the availability of an external energy source for metal uptake by viable yeast cells. For these reasons metal removal from industrial waste water was investigated using non-viable biomass. By immobilizing the yeast cells additional mechanical integrity and stability was conferred apon the biomass. The three types of biomass preparations developed in this study, viz. polyvinyl alcohol (PV A) Na-alginate, PV A Na-orthophosphate and alkali treated polyethylenimine (PEI):glutaraldehyde (GA) biomass pellets, all fulfilled the necessary physical requirements. However, the superior metal accumulating properties of the PEI:GA biomass determined its selection as a biosorbent for bioremediation purposes. Biosorption of heavy metals by PEI:GA biomass is of a competitive nature, with the amount of metal accumulated influenced by the availability of the metal ions. This availability is largely determined by the solution pH. At low pH values the affinity of the biomass for metals decreases, whilst enhanced metal biosorption occurs at higher pHs, ego pH 4.5 - 6.0. PEI:GA biomass pellets can be implemented -as a biosorbent for the bi9remediaiton of high concentration, low-volume metal containing industrial waste. Several options regarding the bioremediation system are available. Depending on the concentration of the metals in the effluent, the bioremediation process can either be used independently or as part of a biphasic remediation system for the treatment of waste water. Initial phase chemical modification may be required, whilst two types of biological systems can be implemented as 'part of the second phase. The PEI:GA biomass can either be contained within continuous-flow fixed bed tanks or continuous-flow stirred bioreactor tanks. Due to the simplicity of the process and the ease with which scale-up is facilitated, the second type of system shows greater application potential for the treatment of this type of industrial waste water than the fixed-bed systems.
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Torres, Eric M. "Microalgae Sorption of Ten Individual Heavy Metals and their Effects on Growth and Lipid Accumulation." DigitalCommons@USU, 2016. https://digitalcommons.usu.edu/etd/4956.
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As underdeveloped nations continue to industrialize and the world population continues to increase, the need for energy, natural resources, and goods will lead to ever increasing heavy metal concentrations in various waste streams that can have damaging effects on plant life, wildlife, and human health. The focus of this study is to understand the impact of individual heavy metals on Nannocholoropsis salina microalgae growth and understand the potential of microalgae to be used as a bioremediation tool for contaminated water systems. Individual metals (As, Cd, Cr, Co, Cu, Pb, Ni, Hg, Se, and Zn) were introduced into growth media. For each metal a baseline concentration was determined based on reported concentrations at various municipal and industrial wastewater sites. In addition to the baseline concentrations, experimentation was conducted at 10X and 40X the baseline to evaluate the potential for severely contaminated systems. Biological growth experimentation was performed in triplicate at the various contaminant concentrations and at 3 different light intensities. Results show nickel significantly reduced growth, while the other metal contaminated systems showed growth between 89% and 99% of the control. Increased heavy metal concentrations resulted in progressively lower growth rates. Lipid analysis shows most baseline metal concentrations slightly decrease or have minimal effects in lipid content. Metals analysis on the biomass showed the majority of the metals in the systems containing Cd, Co, Cu, and Pb were sorbed by the microalgae with minimal metals remaining in the growth media illustrating the effectiveness of microalgae to effectively bioremediate contaminated systems when contamination levels are sufficiently low to not detrimentally impact productivity. Microalgal biomass in the systems containing As, Cr, Ni, and Se showed decreased ability to sorb metal ions. Results show at moderate contamination levels, microalgae can be an effective tool for bioremediation.
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Cáliz, Gelador Joan. "Impact of chlorophenols and heavy metals on soil microbiota: their effects on activity and community composition, and resistant strains with potential for bioremediation." Doctoral thesis, Universitat de Girona, 2011. http://hdl.handle.net/10803/80914.
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Pollution by toxic compounds is one of the most relevant environmental damages to ecosystems produced by human activity and, therefore, it must be considered in environmental protection and restoration of contaminated sites. According to this purposes, the main goal of this doctoral thesis has been to analyse the impact of several chlorophenols and heavy metals on the microbial communities of two typical Mediterranean soils. The ecological risk concentrations of each pollutant, which have been determined according to respirometric activity and changes in the microbial community composition, and the factors that influence on their effective toxic concentrations (bioavailable pollutants) have been analysed in order to predict their potential impact on different soil ecosystems and provide scientific data for the regulation of the soil protection policies. Moreover, resistant microorganisms with pollutant removal capacities have been isolated from artificially contaminated soil microcosms and tested in axenic cultures, to infer their potential usefulness for bioremediation.<br>La contaminació amb compostos tòxics antropogènics és un dels perjudicis ambientals més rellevants per als ecosistemes i, per tant, cal tenir-ho en compte en la protecció ambiental i la restauració de llocs contaminats. Amb aquests propòsits, l’objectiu principal d’aquesta tesi doctoral ha estat analitzar l’impacte de clorofenols i metalls pesants sobre la microbiota de dos sòls típicament mediterranis. S’han analitzat les concentracions de risc ecològic de cada contaminant, determinades segons activitat respiromètrica i canvis en la composició de la comunitat microbiana, i els factors que influeixen en les seves concentracions tòxiques efectives (contaminants biodisponibles), per predir l’impacte potencial sobre diferents ecosistemes edàfics i proporcionar evidències científiques per a les polítiques de protecció del sòl. D’altra banda, a partir de microcosmos edàfics contaminats artificialment, es van aïllar també microorganismes resistents amb capacitat per eliminar els contaminants, que van ser analitzats en cultius purs per avaluar-ne la utilitat potencial en bioremediació.
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Smothers, Daniel Anthony. "Analysis of the bioremediation of heavy metals and chlorinated solvents with emphasis on the utility of molasses injection." Master's thesis, Mississippi State : Mississippi State University, 2002. http://library.msstate.edu/etd/show.asp?etd=etd-10292002-110839.
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Araujo, Santos Ana. "Development of a novel integrated system for bioremediating and recovering transition metals from acid mine drainage." Thesis, Bangor University, 2018. https://research.bangor.ac.uk/portal/en/theses/development-of-a-novel-integrated-system-for-bioremediating-and-recovering-transition-metals-from-acid-mine-drainage(9587ab26-7e31-4728-8206-29850860ccfa).html.
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Mine-impacted water bodies are considered to be one of the most serious threats to the environment. These can be highly acidic and often contain elevated concentrations of sulfate and soluble metals. The microbial generation of H2S by reduction of more oxidized sulfur species, and consequent precipitation of metal sulfides, known as biosulfidogenesis, is a promising technology for remediating acid mine drainage (AMD). The objective of this work was to develop an integrated system for remediating a target AMD at an operating mine in northern Brazil using a single low pH anaerobic sulfidogenic bioreactor (aSRBR) and an aerobic manganese-oxidizing bioreactor. A synthetic version of the mine water, which contained 7.5 mM copper and lower concentrations (< 0.25 mM) of other transition metals (Zn, Ni, Co and Mn) was used in the experimental work. In the first stage, H2S generated in the aSRBR was delivered to an off-line vessel containing synthetic AMD, which removed > 99% copper (as CuS) while no co-precipitation of other metals was apparent. The partly-processed AMD was then dosed with glycerol and fed into the aSRBR where zinc, nickel and cobalt were precipitated. The effect of varying the pH and temperature of the bioreactor was examined, and > 99% of Ni, Zn and Co were precipitated in the aSRBR when it was maintained at pH 5.0 and 35ºC. The bacterial communities, which were included 4 species of acidophilic sulfate-reducing bacteria, varied in composition depending on how the bioreactor was operated, but were both robust and adaptable, and changes in temperature or pH had only short-term impact on its performance. Manganese was subsequently removed from the partly-remediated synthetic AMD using upflow bioreactors packed with Mn(IV)-coated pebbles from a freshwater stream which contained Mn(II)-oxidizers, such as the bacterium Leptothrix discosphora and a fungal isolate belonging to the order Pleosporales. This caused soluble Mn (II) to be oxidised to Mn (IV) and the precipitation of solid-phase Mn (IV) oxides. Under optimised conditions, over 99% manganese in the processed AMD was removed. Metal sulfides (ZnS, CoS and NiS) that had accumulated in the aSRBR over 2 years of operation were solubilised by oxidative (bio)leaching at low pH. With this, ~ 99% Zn, ~ 98% Ni and ~ 92% Co were re-solubilised, generating a concentrated lixiviant from which metals could be selectively recovered in further downstream processes. The use of methanol and ethanol either alone or in combination with glycerol were evaluated as alternative electron donors for biosulfidogenesis. Methanol was not consumed in the bioreactor, though sulfate reduction was not inhibited in the presence of up to 12 mM methanol. In contrast, ethanol was readily metabolised by the bacterial community and sulfate reduction rates were relatively high compared to glycerol. Two acidophilic algae were characterised and their potential to act as providers of electron donors for biosulfidogenesis was also evaluated. Although algal biomass was able to fuel sulfate reduction in pure cultures of aSRB and in the aSRBR, rates were much lower than when either glycerol or ethanol were used.
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Almeida, Tiago Tognolli de. "Potencial biorremediador do fungo endofítico Mucor sp. isolado da macrófita aquática Eichornia crassipes (Mart)." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/64/64133/tde-24042018-105535/.
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Os fungos endofíticos são microrganismos que vivem no interior de tecidos ou órgãos dos vegetais, sem causar danos aos seus hospedeiros. Dentre as inúmeras características desses microrganismos está o seu potencial biorremediador Este trabalho teve como objetivo a avaliação do potencial biorremediador do endófito Mucor sp. isolado de Eichhornia crassipes (Mart.) (Pontederiaceae), verificando a tolerância e capacidade de absorção do metal pesado cádmio (Cd), os efeitos desse metal na morfologia celular e no sistema de defesa antioxidante do fungo, e também o comportamento da planta modelo Solanum lycopersicum cultivar Calabash Rouge, inoculada com o endófito na presença do metal cádmio. Os resultados apresentados indicaram que um fungo endofítico do gênero Mucor, isolado da macrófita aquática E. crassipes, oriunda de uma lagoa contaminada com metais pesados, apresentou resistência a altas concentrações do metal cádmio. Este fungo apresentou uma modificação na sua morfologia em altas concentrações do metal, além de possuir a capacidade de reter este metal, tanto no interior do seu citoplasma, quanto em sua parede celular, o que pode estar ligada a mecanismos de desintoxicação e sequestro de metais relacionados à formação de complexos Cd-GSH. O mesmo fungo também apresentou um aumento na relação GSH/GSSG nos tratamentos com o metal. Os resultados ainda demonstraram que o estresse causado pelo metal induziu a ativação de enzimas antioxidantes SOD, CAT e GR no isolado endofitico. Além disso, este endófito, quando inoculado em plantas de tomate (Solanum lycopersicum), aumentou a capacidade de absorção do metal na parte aérea desta planta, além de promover crescimento da mesma, nos tratamentos sem o metal, Desta forma o isolado endofítico (CM3) Mucor sp. mostrou um potencial biorremediador, podendo ser utilizado como ferramenta para diminuir os danos causados a saúde humana e ao meio ambiente pelos metais pesados, principalmente o metal cadmio, e também na promoção de crescimento de plantas<br>Endophytic fungi live in the interior of plant tissues or organs, without causing harm to their hosts. Among several interesting characteristics of these microorganisms, some of them present a good potential for bioremediation. This study aimed at assessing the bioremediation potential of endophytic fungus Mucor sp. isolated from a Eichhornia crassipes (Mart.) (Pontederiaceae), analyzing chemical absorption ability and fungal tolerance to the heavy metal cadmium (Cd), besides testing the effects of cadmium on the cell morphology, the antioxidant defense system of the fungus, and the behavior of model plant (Solanum lycopersicum) variety Calabash Rouge inoculated with a spore suspension of Mucor sp. in the presence of cadmium. The results indicated that the endophytic fungus isolated from a Eichhornia crassipes (Mart.) plant located in a lagoon contaminated with heavy metals showed resistance to high concentrations of cadmium. The isolated fungus was identified as Mucor sp. The morphology studies demonstrated the occurrence of modifications on the fungus when in high concentrations of the metal. Furthermore, it was possible to verify that the fungus has a capacity to retain metal, both in the cytoplasm and cell wall. This aspect can be linked to detoxification and sequestration mechanisms of metals related to formation of Cd-GSH complexes, since this fungus also presented increase of GSH/GSSG ratio in the treatments with metal. The results also demonstrated that the stress caused by cadmium induces the activation of antioxidant enzymes SOD, CAT and GR in Mucor sp.. Moreover, the inoculation of this fungus in tomato plants increased the biosorption capacity of the cadmium in aerial parts of the plant, besides promoting its growth in the treatments without the metal. Thus the endophytic isolate (CM3) Mucor sp. presented a promising potential as a bioremediator, which can be used as a tool for reducing the damage caused by heavy metals, especially cadmium, to human health and environment
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Fontes, Livia de Carvalho. "Isolamento e seleção de fungos com potencial para biorremediação a partir de ambientes aquáticos com histórico de contaminação por metais pesados." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/42/42132/tde-16082016-115233/.
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Processos estão sendo desenvolvidos a fim de recuperar áreas contaminadas por metais pesados. Assim, estudos que caracterizam fungos que degradam estes poluentes, se fazem necessários. Assim sendo, o objetivo desse trabalho foi caracterizar fungos em ambientes aquáticos contaminados por metais pesados e inserir genes a fim de melhorar absorção de metais pesados. 340 isolados fúngicos resistentes a quatro diferentes metais pesados (Pb, Cd, Cr e Hg) foram selecionados e identificados através de exame direto, microcultivo e seqüenciamento de ITS. Os isolados foram testados quanto a velocidade de crescimento radial em meios suplementados com metais pesados. Trichoderma sp. apresentou VCR de 0,9cm/dia (Pb), VCR de 0,7cm/dia (Cd), VCR de 0,8cm/dia e VCR de 0,9cm/dia(Hg). Curvularia afinis apresentou uma VCR de 0,3cm/dia; Uma cepa do gênero Penicillium apresentou alta VCR na maior concentração testada 0,26cm/dia na concentração de 0,5g/L de Cádmio; Aspergillus apresentou VCR de 0,42cm/dia e Microsphaeropsis arundinis apresentou VCR de 0,24 cm/dia. Trichoderma harzianum apresentou melhor capacidade de retenção de metal e foi observada em MET. Saccharomyces cerevisiae foi transformada com o gene sintético EC20 para aumento a retenção destes metais.<br>Processes are being developed in order to recover areas contaminated by heavy metals. Thus, studies featuring fungi that degrade these pollutants are needed. Therefore, the aim of this study was to characterize fungi in aquatic environments contaminated by heavy metals and insert genes in order to improve absorption of heavy metals. 340 fungal isolates resistant to four different heavy metals (Pb, Cd, Cr and Hg) were selected and identified through direct examination, microculture and ITS sequencing. The isolates were tested for the radial growth rate in media supplemented with heavy metals. Trichoderma sp. presented VCR 0,9cm / day (Pb), VCR 0.7cm / day (Cd), VCR 0.8cm / day and VCR 0,9cm / day (Hg). Curvularia afinis presented a VCR 0.3 cm / day; A strain of Penicillium showed high VCR at the highest concentration tested 0,26cm / day at a concentration of 0.5 g / L of cadmium; Aspergillus presented VCR 0,42cm / day and showed VCR arundinis Microsphaeropsis 0.24 cm / day. Trichoderma harzianum showed better metal holding capacity and was observed in TEM. Saccharomyces cerevisiae was transformed with the synthetic gene EC20 for increasing the retention of these metals.
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Conicelli, Bianca Pirilo. "Biossorção de chumbo e mercúrio pelas linhagens selvagem e recombinante de C. metallidurans em meio aquoso." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-15052017-160603/.
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Nas ultimas décadas o processo de biossorção tem alcançado grande relevância no tratamento de efluentes contendo metais potencialmente tóxicos. O uso de bactérias nesse processo tem obtido destaque, uma vez que possuem inúmeras vantagens. O presente estudo pretendeu avaliar o mecanismo envolvido no processo de biossorção dos íons Pb(II) e Hg(II) por meio das linhagens Cupriavidus metallidurans (CH34) e Cupriavidus metallidurans (CH34/pCM3). Dentre os modelos estudados a isoterma de Langmuir foi a que melhor se ajusta ao processo de adsorção, apresentando uma capacidade máxima de adsorção (qmax) de 0,98 mg.g-1 para o Hg(II) e 86,2 mg.g-1 para o Pb(II), para a linhagem selvagem. Já para a linhagem recombinante o qmax obtido foi 3,4 mg.g-1 para o mercúrio e 172,4mg g-1 para o chumbo. Baseado nos valores referentes à energia livre de Gibbs (ΔG) o processo de retenção ocorreu de forma química e espontânea. A influencia do pH foi avaliada por meio de estudo competitivo entre os íons metálicos, em níveis equimolares. O valor que melhor contemplou a adsorção para ambos os íons foi o pH 7,0, tendo o Pb(II) demonstrado maior capacidade de retenção. Em pH 2,0 houve maior retenção do Hg (II), já em pH 10,0 o Pb(II) obteve maior retenção. Indicando que o meio influencia diretamente na competição dos íons metálicos pelos sítios ativos. Constatou-se que a retenção do metal é robusta e estável ao longo de 6 meses. Os resultados indicam que a Cupriavidus metallidurans (CH34/pCM3) pode ser uma boa opção para biossorção de íons metálicos por meio de biorreator.<br>In the last decades the biosorption process, has achieved great relevance treatment of effluents containing toxic metals. The use of bacteria in the process has several advantages. This study aimed to evaluate the mechanism involved in the biosorption process of Pb (II) and Hg (II) ions by C. metallidurans (CH34) and C. metallidurans (CH34/pCM3) genetically modified strain. The Langmuir isotherm was the best adjusts to the adsorption process. The maximum adsorption capacity (qmax) of 0.98 mg.g-1 for Hg (II) and 86.2 mg.g -1 to Pb (II), for a wild strain (pH 7,0). However, for a recombinant strain, the qmax was 3.4 mg.g-1 for mercury and 172.4 mg.g-1 for the lead (pH 7,0). Based on the Gibbs free energy (ΔG) values on the adsorption process, it occurred chemically and spontaneously. The Hg(II) presented high adsorption capacity at pH=2 in comparing with Pb(II). While Pb(II) presented high adsorption capacity at pH=10. The studies of binding process was robust and stable for 6 months. The results indicate that Cupriavidus metallidurans (CH34/pCM3) can be a good option for biosorption of metal in a bioreactor.
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Shetty, Ameesha R. "Metal anion removal from wastewater using chitosan in a polymer enhanced diafiltration system." Link to electronic thesis, 2006. http://www.wpi.edu/Pubs/ETD/Available/etd-050406-115241/.
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Hornink, Karina Regueira. "Isolamento e identificação de bactérias com potencial para realizar biorremediação de cobre." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/87/87131/tde-07032016-112408/.
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A aplicação de microrganismos capazes de adsorver metais se destaca dentre as técnicas para biorremediação ambiental. O objetivo deste trabalho foi isolar e identificar bactérias com potencial de emprego nesta tecnologia. A partir de amostras de solo, água e sedimentos coletadas da mina Sossego da VALE em 4 eventos de coleta, foram isoladas 73 bactérias resistentes à altas concentrações de Cu2+. Para a identificação dos isolados utilizaram-se diversos métodos: MALDI-TOF; sequenciamento de parte dos genes 16S rRNA e rpoD; construção de árvores filogenéticas; e provas bioquímicas. Foram selecionadas 12 bactérias pertencentes a pelo menos, 8 espécies diferentes, sendo a maioria pertencente ao gênero Cupriavidus. 75% dos isolados apresentou resistência a Cu2+ superior a de C. metallidurans CH34, bactéria mais resistente a Cu2+ conhecida. Valores de adsorção de Cu2+ superiores aos desta bactéria também foram observados em 5 isolados. Os resultados obtidos indicam que os isolados selecionados apresentam alto potencial para aplicação em biorremediação ambiental.<br>The application of microorganisms capable of adsorbing toxic metals stands out from other bioremediation techniques. This study aimed to isolate and identify bacteria with potential for bioremediation of environments contaminated by copper ions. From soil, water and sediment samples collected at VALE`s Sossego mine collected at 4 different occasions, 73 copper resistant bacteria were isolated. For the identification of the isolates, various methods were used: MALDI-TOF, sequencing of part from the genes rRNA and rpoD; construction of phylogenetic trees; and biochemical tests. 12 bacteria that belong to at least 8 different species were selected. 75% of the isolates were resistant to Cu2+ exceeding C. metallidurans CH34, the, most resistant bacteria to Cu2+ known. The ion adsorption capacity of 5 isolates was greater than those for C. metallidurans. The results obtained for the bacterial isolates indicate that they have a high potential for application in environmental bioremediation.
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Del, Busso Zampieri Bruna. "Metais em áreas portuárias e sua influência na dinâmica microbiana : da caracterização do problema à busca de soluções /." Rio Claro, 2020. http://hdl.handle.net/11449/192376.
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Orientador: Ana Julia Fernandes<br>Resumo: Atividades portuárias são consideradas fontes de contaminação por metais, que em altas concentrações são tóxicos aos microrganismos, podendo mudar o tamanho, a composição e a atividade da comunidade microbiana. Essa pressão seletiva faz com que bactérias desenvolvam mecanismos para combater o estresse causado por eles. Diversos grupos de microrganismos que desenvolvem sistemas de tolerância a metais podem fazer sua biorremediação. Bactérias redutoras de sulfato (BRS) podem, devido ao seu metabolismo, precipitar metais facilitando sua remoção. A hipótese é que em áreas portuárias exista uma alteração na comunidade microbiana onde são favorecidos microrganismos resistentes, aumentando a chance do isolamento de bactérias resistentes com potencial biotecnológico. Portanto o objetivo dessa tese foi avaliar a influência da contaminação de metais na comunidade microbiana em áreas portuárias e na seleção de cepas resistentes, e isolar cepas de BRS com potencial biotecnológico. Para isso, foram coletados sedimentos de 2 áreas portuárias (Santos e São Sebastião) e uma área pristina (Ubatuba). Foram caracterizadas variáveis ambientais do sedimento (como pH, salinidade, temperatura, oxigênio dissolvido, porcentagem de matéria orgânica, concentrações de Cr, Cu, Cd e Zn). Foi extraído DNA total do sedimento para caracterização da comunidade utilizando sequenciamento Mi-Seq. Os sedimentos serviram como inóculo para isolamento de cepas que foram submetidas a testes de resistência aos metais.... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: Port activities are considered sources of metal contamination, which in high concentrations are toxic to microorganisms, and can change the size, composition and activity of the microbial community. This selective pressure forces bacteria to develop resistance mechanisms. Several microorganisms groups that develop metal tolerance systems can perform their bioremediation. One example is Sulfate-reducing bacteria (SRB). Because of their metabolism, this group can precipitate metals facilitating their removal. In this way, the hypothesis is that in port areas there is a change in the microbial community where resistant microorganisms are favored, increasing the chance of isolation of resistant bacteria with biotechnological potential. Therefore, the objective of this thesis was evaluate the influence of metal contamination in the microbial community in port areas and in the selection of resistant strains, and to isolate strains of SRB with biotechnological potential. For this, sediments were collected from two port areas (Santos and São Sebastião) and one pristine area (Ubatuba). Sediment environmental variables were characterized (such as pH, salinity, temperature, dissolved oxygen, percentage of organic matter, concentrations of Cr, Cu, Cd and Zn). Total DNA was extracted from the sediment for community characterization using Mi-Seq sequencing. The sediments was used as inoculum for strain isolation, and the metal resistance was checked. The most contaminated sediments also wa... (Complete abstract click electronic access below)<br>Doutor
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Santos, Lílian Castilho dos. "Efeito do cobre na população de bactérias e fungos do solo, associação ectomicorrízica e no desenvolvimento de mudas de eucalipto e canafístula." Universidade Federal de Santa Maria, 2006. http://repositorio.ufsm.br/handle/1/5549.
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The microrganisms are sensitive to the presence of determined concentrations of copper being considered biorremediadores able to move metal through active and passive processes, accumulating them in his cellular compartments The aim of this study was to evaluate the effects of copper on the soil bacteria and fungi population and ectomycorrhizal association, as well as on the growth of eucalyptus (Eucalyptus grandis W. Hill ex Maiden) and canafístula (Peltophorum dubium (Sprengel) Taubert) seedlings. The soil samples were collected in reject, adjacent, eucalyptus cultivation, pinus with 2 and 10 year old area, in the Camaquã Minas, Caçapava, Rio Grande do Sul, Brazil. The counting of bacteria and fungi soil population was carried out in the laboratory in culture medium, incubated 8 days, to 25 ºC. Subsequently, experiment was installed to determine the copper level effect (0, 100, 200, 300 mg kg-1 of Cu) on eucalyptus and canafistula seedlings, inoculated or not with the Pisolithus microcarpus (Cooke & Massee) Cunn. UFSC Pt 116. It was determine the height, stem diameter, aerial fresh
matter and root dry matter, and ectomycorrhizal colonization percentage, at 110 days. The highest average for the total bacteria population was found in the adjacent and eucalyptus cultivation area, for the soil fungi population was in the adjacent area. The copper quantity of 203 mg dm-3 inhibits the bacteria and fungi soil population. The inoculation of the seedlings of eucalyptus and canafístula with P. microcarpus UFSC Pt 116 increase the development of aerial fresh matter and height of seedlings. The results show that the canafístula is able to form ectomycorrhizal association with P. microcarpus UFSC Pt 116 (4,96 %). The development of eucalyptus and canafístula seedlings were inhibited by the copper level even inoculated with P. microcarpus UFSC Pt 116. The population of bacteria and fungi in the soil as well as the seedlings of eucalyptus and canafístula are straightly influenced by the copper level in the soil, being favoured by the inoculation with P. microcarpus UFSC Pt 116.<br>Os microrganismos são sensíveis à presença de determinadas concentrações de cobre sendo considerados biorremediadores capazes de remover metais através de processos ativos e passivos, acumulando-os em seus compartimentos celulares.O
trabalho teve como objetivo avaliar o efeito do cobre sobre a população de fungos, bactérias do solo e associação ectomicorrízica, bem como avaliar a ação deste no
desenvolvimento de mudas de eucalipto (Eucalyptus grandis W. Hill ex Maiden) e canafístula (Peltophorum dubium (Sprengel) Taubert). As amostras de solo foram coletadas em área de rejeito, margem, cultivo de eucalipto, pinus com 2 anos e com 10 anos de cultivo, nas Minas do Camaquã, Caçapava, RS. A contagem da população de fungos e bactérias do solo foi realizada em meio de cultura incubado por 8 dias a 25 ºC. Posteriormente, foi instalado experimento para avaliar o efeito do cobre (0, 100, 200, 300 mg kg-1 copper) no desenvolvimento de mudas de eucalipto e canafístula inoculadas ou não com Pisolitus microcarpus (Cooke & Massee) Cunn. UFSC Pt 116. Avaliou-se altura, diâmetro do colo, matéria fresca da parte aérea e radicular, matéria seca da parte aérea e percentagem de colonização ectomicorrízica aos 110 dias. As maiores médias para a população de bactérias totais foram encontradas nas áreas de
margem e cultivo de eucalipto, para a população de fungos do solo foram em área de margem. A quantidade de 203 mg dm-3 de cobre inibe a população de bactérias e fungos do solo. A inoculação das mudas de eucalipto e canafístula com P. microcarpus favoreceu o desenvolvimento da matéria fresca da parte aérea e radicular e da altura das plantas. Os resultados mostram também que a canafístula é capaz de realizar associação ectomicorrízica com P.microcarpus (4,96%). O desenvolvimento das plântulas de eucalipto e canafístula foram inibidas pelos niveis de cobre mesmo
inoculadas com P. microcarpus UFSC Pt 116. A população de bactérias e fungos do solo, bem como as mudas de eucalipto e canafístula são diretamente influenciada pelo teor de cobre do solo, sendo favorecidas pela inoculação do Pisolitus microcarpus UFSC Pt 116.
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Andersson, Eva Lotta. "Analysis of Various Bioreactor Configurations for Heavy Metal Removal Using the Fungus Penicillium ochro-chloron." Digital WPI, 2000. https://digitalcommons.wpi.edu/etd-theses/814.
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Penicillium ochro-chloron (ATCC strain # 36741), a filamentous fungus with the capability for removing copper ions from aqueous solutions, was studied as a possible biological trap (biotrap) for remediation of heavy metal contaminants in industrial wastewaters. This research demonstrated that in shake flasks the fungus removed copper from surrogate wastewater with 100mg/L copper contamination by as much as 99%. These results did not translate to the bioreactor configuration of a packed bed column, as channeling occurred through the bed, shown by conductivity tracer studies. A fluidized bed configuration was studied and resulted in copper removal of 97%, with a capacity of 149 mg[Cu]/g dry weight biomass, under the conditions of 50% dissolved oxygen. For dissolved oxygen concentrations below the critical oxygen concentration for the fungus (20% saturation) there was minimal copper removal. Mixing studies in the fluidized bed reactor showed that the system was diffusion limited. Mathematical modeling using first order kinetics associated with diffusion limited reactions resulted in rate constants for Cu 2+ uptake of approximately 0.031 h -1 , which were dependent on the dissolved oxygen concentration. Modeling of the reaction with a second order kinetic equation showed that there are possibly factors regulating copper uptake besides oxygen. Electron microscopy showed that in some instances the copper removed was retained as large porous spherical extracellular precipitates. Energy Dispersive X-ray (EDX) analysis has shown similar complexes to be copper phosphate precipitates (Crusberg, 1994). Removal of heavy metal contaminants from wastewater discharge is a necessity for many industries, due to environmental concerns and federal regulations. The use of a biological system for the removal and recycling of heavy metals could prove more economical than currently used physio-chemical processes.
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Ayala-Parra, Pedro. "Novel Electron Donors for Anaerobic Remediation of Acid Rock Drainage." Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/612409.
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We initially studied the treatment of acid rock drainage using a sulfate-reducing bioreactor with zero-valent iron as the electron donor. The results demonstrate that this electron donor can serve as the sole exogenous slow-release electron donor to drive sulfate reduction over 400 operational days at short HRTs (1-3 days). The synthetic acid rock drainage contained high heavy metal concentrations (up to 50 mg/L of copper) and pH values ranging from 3.0 to 7.0. Treatment of this acid rock drainage efficiently removed Cu, Cd and Pb (>99.7%) and increased pH to circumneutral values (7.3-7.7). Elemental analysis indicated that formation of insoluble metal sulfides was responsible for the effective metal removal in the zero valent iron columns. In the second study, three inoculated columns containing anaerobic granular sludge were fed a synthetic medium containing H₂SO₄ and Cu²⁺ during the experimental period of 4 months. Algae biomass promoted 80% of sulfate removal (12.7 mg SO₄²⁻ d-1), enabling near complete Cu removal (>99.5 %), and alkalinity generation, raising the effluent pH to 6.5. In the algae amended columns Cu²⁺ was precipitated with biogenic H2S produced by sulfate reduction. Whole cell algae and lipid extracted algae biomasses were both shown to be effective e-donors in driving sulfate reduction of ARD, thus enabling the precipitation and removal of Cu²⁺. The precipitate retained in the columns was composed mostly of insoluble copper sulfide formed from the biogenic sulfide, as shown by sequential extraction and X-ray diffraction. In the third study, several pretreatments, i.e., thermal, chemical, sonication and combinations thereof, that enhance anaerobic biodegradability of Chlorella protothecoides biomass were evaluated. The results demonstrate that anaerobic digestion of pretreated Chlorella protothecoides biomass generates energy-rich methane and recovers nitrogen nutrients. Sonication of algal biomass under optimized conditions provided a significant increase in the methane yield (327 mL STP CH₄ g⁻¹ VS) compared to untreated algae (146 mL STP CH₄ g⁻¹ VS), as demonstrated in anaerobic digestion experiments incubated for 41 days. In contrast, thermal pretreatment provided only a moderate increase of the methane yield and alkaline treatment led to a decrease of the methane yield compared to the untreated algal biomass. Additionally, sonication treatment provided a 4.1-fold increase in the release of ammonia nitrogen during anaerobic digestion of the algal biomass. In the fourth study, the nutrient recovery and biogas generation from the anaerobic digestion of waste biomass from algal biofuel production was investigated. Anaerobic digestion of whole cell and lipid extracted Chlorella sorokiniana-1412 released 48.1 and 61.5% of the total algal nitrogen as NH₄⁺-N, and 87.7 and 93.6% of the total algal P as soluble P, respectively. The biochemical methane potential, quantified through the methane yield of whole cell algae and lipid extracted algae, was 0.298 and 0.253 L methane/g algal volatile solids, respectively. The conversion of lipid extracted algae and whole cell algae biomasses to methane was very similar (38 and 41% on a COD basis, respectively), indicating that the energy yield was not significantly lowered by extraction of the lipid fraction (which accounted for 9% of algal dry weight). Sonication improved the access of hydrolytic enzymes to algal biopolymers, compensating in part for the energy lost due to lipid extraction. The above results demonstrate that algal waste from the biodiesel industry has the potential to be recycled through anaerobic digestion into valuable nutrients and energy. These studies indicate that zero valent iron and algae biomass are promising reactive materials for the treatment of acid rock drainage in sulfate-reducing permeable reactive barrier systems. Additionally, to promote algae cultivation for the biodiesel industry, the anaerobic digestion of algae residues can generate nutrients and energy, making algae cultivation more fiscally attractive.
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Agbeze-Onuma, Maduka. "Bioremediation of a former manufactured gas plants (FMGP) site contaminated with a complex mixture of heavy metals, organic and inorganic substances using soil washing technique." Thesis, University of Strathclyde, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.502359.
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This study investigated the potential treatability of a representative soil sample, holding a complex mixture of metals, organic and inorganic contaminants, from the site of a Former Manufactured Gas Plant (FMGP) using a combination of soil washing technique and bioremediation. The contaminants treated included a range of heavy metals (lead, chromium, copper, mercury etc), inorganic chemicals (chlorides, sulphates, cyanides etc), and organic compounds (polycyclic aromatic hydrocarbons (PAHs), Gasoline Range Organics (GRO), Diesel Range Organics (DRO), Methyl tertiary butyl ether (MTBE), and benzene etc).
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Dimitriou, Ioannis. "Performance and sustainability of short-rotation energy crops treated with municipal and industrial residues /." Uppsala : Dept. of Short Rotation Forestry, Swedish University of Agricultural Sciences, 2005. http://epsilon.slu.se/200544.pdf.
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Dragana, Tamindžija. "Isolation and characterization of Cr(VI) tolerant soil bacteria." Phd thesis, Univerzitet u Novom Sadu, Prirodno-matematički fakultet u Novom Sadu, 2019. https://www.cris.uns.ac.rs/record.jsf?recordId=110336&source=NDLTD&language=en.
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In this study, tolerance of soil bacteria to hexavalent chromium (Cr(VI)) was investigated. First, influence of high chromium levels of anthropogenic and geogenic origin on the soil cultivable bacterial community was examined. Next, a number of bacterial strains with high Cr(VI) tolerance were isolated from diverse environmental samples such as soil, sediment, water and waste material. Strains were identified and tested for the level of Cr(VI) tolerance and the ability toreduce toxic Cr(VI) to more innocuous Cr(III). Selected <em>Bacillus cereus</em> group strains were further characterized - their morphological and biochemical characteristics, 16S rRNA and pycA gene sequences, biofilm formation potential and resistance to other heavy metals were determined. Also, more detailed study of their tolerance level and Cr(VI) reduction was conducted. Strain with the highest resistance together with the control chromate sensitive strain were analyzed by STEM EDS for their cellular and endospore Cr content under different conditions. Results indicate Cr(VI) tolerant bacteria are present both in low and high Cr environments. Majority of isolates belonged to the <em> B. cereus </em> group indicating its overall high tolerance to Cr(VI). Certain strains exhibited high tolerance and reduction ability, indicating their possibleusefulness in practical bioremediation application. STEM EDS analysis of Cr(VI)-sensitive <em> B. subtilis </em> PY79 strain and Cr(VI)-resistant <em>B. cereus </em> group strain NCr1a revealed significant differences in their response to Cr(VI) and in their Cr cellular and endospore content.<br>U ovom radu ispitana je tolerantnost zemljišnih bakterija na šestovalentni hrom (Cr(VI)). Prvo, ispitan je uticaj visokog nivoa hroma antropogenog i geogenog porekla na kultivabilnu bakterijsku zajednicu zemljišta. Dalje, izolovani su bakterijski sojevi sa visokom tolerancijom na Cr(VI) iz različitih sredinskih uzoraka kao što su zemljište, sediment, voda i otpadni materijal. Sojevi su identifikovani i određen je nivo njihove Cr(VI) tolerancije i sposobnost redukcije toksičnog Cr(VI) u manje toksični Cr(III). Odabrani sojevi <em>Bacillus cereus </em> grupe su dalje karakterisani – određene su njihove morfološke i biohemijske karakteristike, 16S rDNK i pycA sekvence, potencijal formiranja biofilma i otpornost na druge teške metale. Takođe, sprovedeno je detaljnije ispitivanje njihove tolerancije i redukcije Cr(VI). Soj sa najvišom otpornošću je uporedo sa kontrolnim osetljivim sojem analiziran pomoću STEM EDS na sadržaj hroma u ćelijama I endosporama u različitim uslovima. Rezultati ukazuju da su bakterije tolerantne na Cr(VI) prisutne i u sredinama sa niskim i sa visokim koncentracijama hroma. Većina izolata pripadala je B. cereus grupi što ukazuje na njenu uopšteno visoku otpornost na Cr(VI). Pojedini sojevi su pokazali visoku otpornost i sposobnost redukcije Cr(VI), što ukazuje na mogućnost njihove praktične primene u bioremedijaciji. STEM EDS analiza osetljivog<em> B. subtilis</em> PY79 soja i Cr(VI)- rezistentnog soja <em>B. cereus</em> grupe NCr1a otkrila je značajne razlike u njihovom odgovoru na Cr(VI) i sadržaju Cr u njihovim ćelijama i endosporama.
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Vieira, Thaís Maitan. "Avaliação físico-química, ecotoxicológica e biorremediação microbiológica de bases e pigmentos de tintas acrílicas." Universidade Federal de Goiás, 2016. http://repositorio.bc.ufg.br/tede/handle/tede/6643.
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Previous issue date: 2016-10-14<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES<br>The growth of civil construction and industrial activities is increasing environmental concern due to the consequent release of organic and inorganic compounds in nature, arising from these activities. The use of vehicles, pigments, additives and solvents, corresponds to an example of activity that causes environmental impacts poorly studied. It is known that the construction workers use water to clean work equipment and most of the time, the disposal of this water does not suffer any previous treatment. Moreover, the very paint industries also generate waste in need of treatment. In this sense, the objective of this study is to analyze the chemical compositions, the harmful effects to aquatic environments and develop bioremediation processes for different commercial acrylic paints and propose to society the use of foundations and pigments less impact to the environment. With regard to potentially toxic chemicals, C and BFA foundations are those with lower levels of these chemicals. Among the pigments, the Yellow ZC, Blue and Green are those who had the lowest levels of potentially impactful chemicals from an environmental point of view. Considering the VOC present in the bases and pigments, the foundations A and B, and the pigments violet, Yellow NT and Yellow US are the most suitable, because they showed the presence of VOC less dangerous. The ecotoxicological point of view, the foundations A, B and C and the pigments violet, Red, Black, Yellow US and Yellow NT are the most suitable because of lower toxicity. Thus, considering the environmental and occupational exposure approach, the BFA foundation is not advisable to use the foundations A and B must be used indoors and the foundation C outdoors. For pigments advises to use the colors Violet, Yellow NT and Yellow US for indoor, and Yellow ZC and Blue to external environments without the other pigments are vetted to be added in small amounts the bases. Regarding the bioremediation of aquatic environments freshwater by the presence of foundations and pigments, Bacillus cereus (CEM 2) showed greater efficiency in bioflocculation of the compounds in 24 hours, demonstrating potential for biotechnological use in the bioremediation for acrylic paints waste.<br>O crescimento da construção civil e industrial vem aumentando a preocupação ambiental devido a consequente liberação de compostos orgânicos e inorgânicos na natureza, oriundos dessas atividades. O uso de tintas compostas por veículos, pigmentos, aditivos e solventes, corresponde a um exemplo de atividade que causa impactos ambientais ainda pouco estudados. Sabe-se que os trabalhadores da construção civil utilizam da água para limpeza de seus equipamentos de trabalho e, na maioria das vezes, o descarte dessa água não sofre nenhum tratamento prévio. Além disso, as próprias indústrias de tintas também geram efluentes que precisam de tratamento. Nesse sentido, o objetivo desse trabalho foi analisar as composições químicas, os efeitos deletérios para ambientes aquáticos e desenvolver processos de biorremediação para diferentes tintas acrílicas comerciais, propondo à sociedade a utilização de bases e pigmentos menos impactantes ao meio ambiente. Com relação aos elementos químicos potencialmente tóxicos, as bases C e BFA são as que apresentam menores teores desses elementos químicos. Dentre os pigmentos, o Amarelo ZC, o Azul e o Verde são os que apresentaram os menores teores dos elementos químicos potencialmente impactantes do ponto de vista ambiental. Considerando os VOC presentes nas bases e pigmentos, as bases A e B e os pigmentos Violeta, Amarelo NT e Amarelo US são os mais indicados, pois apresentaram a presença de VOC com menor periculosidade. Do ponto de vista ecotoxicológico, as bases A, B e C e os pigmentos Violeta, Vermelho, Preto, Amarelo US e Amarelo NT são os mais indicados devido a menor toxicidade. Com isso, considerando o enfoque ambiental e de exposição ocupacional, a base BFA não tem o uso aconselhável, as bases A e B devem ser usadas em ambientes internos e a base C em ambientes externos. Para os pigmentos aconselha-se o uso das cores Violeta, Amarelo NT e Amarelo US para ambientes internos e Amarelo ZC e Azul para ambientes externos, sem que os demais pigmentos sejam vetados por serem adicionados em pequenas quantidades as bases. Com relação a biorremediação de ambientes aquáticos dulcícolas pela presença de bases e pigmentos, o Bacillus cereus (CEM 2) apresentou maior eficiência na biofloculação dos compostos em 24 horas, demonstrando potencial biotecnológico de sua utilização como biorremediador para efluentes de tintas acrílicas.
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Dago, Busquets Àngela. "Aplicació de la detecció electroquímica a l’estudi de fitoquelatines i dels seus complexos metàl·lics en mostres sintètiques i naturals." Doctoral thesis, Universitat de Barcelona, 2014. http://hdl.handle.net/10803/131400.
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L’objectiu general de la present Tesi Doctoral és la separació i la detecció de molècules d’interès biològic que contenen grups tiols i dels seus complexos metàl•lics en mostres sintètiques i naturals utilitzant la cromatografia de líquids en fase inversa amb detecció electroquímica.
La fitoremediació és una tecnologia basada en l’ús de plantes per eliminar contaminants del medi ambient o reduir-ne la seva toxicitat fins a fer-los innocus. Les fitoquelatines són pèptids rics en cisteïna que sintetitzen les plantes, les algues i alguns fongs i que s’enllacen als metalls pesants mitjançant el grup tiol. Les fitoquelatines estan involucrades en la desintoxicació i l’homeòstasi dels metalls pesants, i és per això que l’estudi de la complexació d’aquestes molècules amb els metalls pesants és d’especial interès.
Per tal d’assolir l’objectiu general, es divideix la Tesi en dos parts ben diferenciades: la primera dirigida al desenvolupament de la metodologia de separació i detecció de les fitoquelatines sintètiques i dels seus complexos amb Hg(II); i la segona dedicada a l’aplicació d’aquesta metodologia a sistemes naturals. Per a aquesta segona part, es seleccionen plantes cultivades en presència de diversos metalls pesants, ja sigui de forma artificial com natural.
Aquesta Tesi es presenta com l’inici d’una nova línia de recerca del grup d’Electroanàlisi dedicada a l’estudi de la complexació de metalls pesants tòxics per les fitoquelatines utilitzant la cromatografia de líquids d’alta resolució (HPLC) en fase inversa acoblada a la detecció electroquímica. Aquesta metodologia es presenta com un mètode selectiu, sensible, senzill i econòmic desenvolupat paral•lelament a les tècniques voltamperomètriques estàtiques, àmpliament utilitzades al grup de recerca, i com una alternativa més econòmica a la detecció per espectrometria de masses globalment utilitzada en estudis de fitoremediació.
La idea principal d’aquesta Tesi Doctoral és la separació i la detecció de fitoquelatines i altres molècules relacionades, així com dels seus complexos amb mercuri. Per tant, la primera part de la memòria (I. Introducció) que consta de tres capítols, està dedicada a la presentació del tema per situar-nos dins de context. A la segona part (II. Metodologia aplicada) s’explica amb detall els fonaments de les tècniques instrumentals i quimiomètriques utilitzades en la present Tesi Doctoral. A la tercera part (III. Experimental) es repassa la instrumentació, els reactius i els procediments de treball utilitzats. Aquesta memòria de Tesi Doctoral es presenta com a compendi de publicacions; els treballs publicats i la discussió dels resultats obtinguts es disposa a la quarta part de la memòria (IV. Resultats i discussió).
Finalment, a la cinquena part de la memòria (V. Conclusions) es presenten les conclusions generals d’aquesta Tesi i a la sisena i última part (VI. Bibliografia) les referències bibliogràfiques consultades.<br>El objetivo general de esta tesis doctoral es la separación y detección de moléculas de interés biológico que contienen grupos tiol y de sus complejos metálicos en muestras sintéticas y naturales, usando la cromatografía de líquidos en fase reversa con detección electroquímica.
La fitoremediación es una tecnología basada en el uso de plantas para eliminar contaminantes del medio ambiente o reducir su toxicidad hasta hacerlos innocuos. Las fitoquelatinas son péptidos ricos en cisteína que sintetizan las plantas, las algas y algunos hongos y que se enlazan a los metales pesados mediante el grupo tiol. Las fitoquelatinas están involucradas en la desintoxicación y la homeostasis de los metales pesados mediante la quelación de estos iones en el citosol y el almacenaje posterior de estos complejos en las vacuolas. Éste es el motivo por el cual el estudio de la complejación de estas moléculas con los metales pesados es de especial interés.
Para lograr este objetivo general, la tesis se divide en dos partes bien diferenciadas: una primera parte dirigida al desarrollo de la metodología de separación y detección de las fitoquelatinas sintéticas y de sus complejos con Hg(II); y la segunda parte dedicada a la aplicación de esta metodología a sistemas naturales. Para esta segunda parte, se seleccionan plantas cultivadas en presencia de distintos metales pesados, ya sea de forma artificial como natural.
Se han desarrollado diversas metodologías para el análisis de fitoquelatinas y compuestos relacionados, entre las cuales la espectrometría de masas es la técnica más usada. El objetivo de esta tesis es desarrollar una metodología analítica sensible y barata que combine la cromatografía de líquidos de alta resolución con la detección electroquímica utilizando un electrodo de carbono vitrificado. Con esta metodología no sólo se separan i detectan las fitoquelatinas i sus compuestos relacionados sino también sus complejos con el Hg. Entre todos los metales pesados, se escoge el Hg(II) para los estudios de complejación de fitoquelatinas debido a su elevada estabilidad de los complejos formados, aparte de ser un metal altamente toxico con graves efectos perjudiciales para la salud y para el medio ambiente.
En la segunda parte de la tesis, esta metodología se aplica al estudio de plantas cultivadas en presencia de distintos metales pesados. Primeramente se consideran plantas de la especie Hordeum vulgare cultivadas en presencia de Hg(II) y en presencia simultánea de Hg(II) y Cd(II), y se evalúa la síntesis de fitoquelatinas provocada por estos metales tóxicos. De forma similar se evalúa la capacidad inductora de fitoquelatinas de distintos metales pesados, como son el Hg(II), el Cd(II), el Pb(II) y el As(III) y se compara la capacidad para inducir fitoquelatinas de cada uno de ellos. Finalmente se estudian plantas contaminadas con Hg de forma natural, procedentes de la zona de Almadén. Esta zona es mundialmente conocida por las minas de Hg más grandes que se han descubierta hasta la actualidad. Por este motivo, este estudio es de especial interés ya que permite profundizar en los mecanismos naturales que han desarrollado las plantas para combatir la toxicidad del mercurio.
Debido a que esta tesis opta a la Mención Internacional de Doctorado, en un último capítulo se presentan los resultados obtenidos en la estancia pre-doctoral realizada a la Facultad de Farmacia de la Université Libre de Bruxelles (Bélgica) bajo la supervisión del Professor Jean-Michel Kauffmann. La temática de la estancia efectuada en este centro europeo se enmarca perfectamente dentro del proyecto de tesis, ya que amplía los sistemas de detección de compuestos tiólicos con la utilización de electrodos de plata.
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JIN, PENG. "THE IMPACT OF CADMIUM ON A MULTI-SPECIES BIOFILM DEGRADING NAPHTHALENE AND THE ROLE OF HYDROGEN PEROXIDE IN CADMIUM-BIOFILM INTERACTION." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1173750294.
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Silva, Bárbara Pereira da. "Identificação de bactérias isoladas de elementos metálicos de torres de transmissão de energia elétrica e avaliação de resistência à metais pesados." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/87/87131/tde-13092011-140905/.
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A corrosão metálica é um problema que afeta a economia mundial, sendo responsável pelo aumento dos custos de geração, transmissão e distribuição de energia elétrica e pode ser influenciada por atividades microbianas, podendo levar a aceleração ou inibição do processo. O presente trabalho teve por objetivo isolar e identificar as bactérias associadas a processos de corrosão em torres de transmissão de energia, bem como avaliar a resistência destas bactérias a diferentes metais pesados buscando selecionar micro-organismos com potencial para biorremediação. A identificação taxonômica dos isolados associados a elementos metálicos foi efetuada por análise filogenética das sequências parciais do gene RNA ribossomal 16S, resultando em 101 bactérias distribuídas em oito gêneros: Lysinibacillus, Serratia, Stenotrophomonas, Pseudomonas, Exiguobacterium, Chryseobacterium, Bacillus e Acinetobacter. Todos os gêneros foram resistentes a mais de um metal, sendo que o metal que menos afetou o crescimento dos isolados foi o cromo e o que mais afetou foi o mercúrio.<br>Metallic corrosion is a problem that affects the world economy, being responsible for the increased costs of generating, transmission and distribution of electricity and can be influenced by microbial activities, leading to inhibition or acceleration of the process. This study aimed to isolate and identify bacteria associated with corrosion processes in metallic structures of power transmission towers, as well as evaluating the resistance of these bacteria to different heavy metals, in order to select microorganisms with potential for biorremediation. The taxonomic identification of the isolates of bacteria associated with metallic elements was performed by phylogenetic analysis of partial sequences of 16S ribosomal RNA gene, resulting in 101 bacteria distributed in eight genera: Lysinibacillus, Serratia, Stenotrophomonas, Pseudomonas, Exiguobacterium, Chryseobacterium, Bacillus and Acinetobacter. All genera were resistant to more than one metal. Chromium and mercury were the metals that least and most affected the growth of isolates, respectively.
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CONICELLI, BIANCA P. "Biossorção de chumbo e mercúrio pelas linhagens selvagem e recombinante de C. metallidurans em meio aquoso." reponame:Repositório Institucional do IPEN, 2017. http://repositorio.ipen.br:8080/xmlui/handle/123456789/27961.
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Submitted by Marco Antonio Oliveira da Silva (maosilva@ipen.br) on 2017-10-27T12:25:12Z
No. of bitstreams: 0<br>Made available in DSpace on 2017-10-27T12:25:12Z (GMT). No. of bitstreams: 0<br>Nas ultimas décadas o processo de biossorção tem alcançado grande relevância no tratamento de efluentes contendo metais potencialmente tóxicos. O uso de bactérias nesse processo tem obtido destaque, uma vez que possuem inúmeras vantagens. O presente estudo pretendeu avaliar o mecanismo envolvido no processo de biossorção dos íons Pb(II) e Hg(II) por meio das linhagens Cupriavidus metallidurans (CH34) e Cupriavidus metallidurans (CH34/pCM3). Dentre os modelos estudados a isoterma de Langmuir foi a que melhor se ajusta ao processo de adsorção, apresentando uma capacidade máxima de adsorção (qmax) de 0,98 mg.g-1 para o Hg(II) e 86,2 mg.g-1 para o Pb(II), para a linhagem selvagem. Já para a linhagem recombinante o qmax obtido foi 3,4 mg.g-1 para o mercúrio e 172,4mg g-1 para o chumbo. Baseado nos valores referentes à energia livre de Gibbs (ΔG) o processo de retenção ocorreu de forma química e espontânea. A influencia do pH foi avaliada por meio de estudo competitivo entre os íons metálicos, em níveis equimolares. O valor que melhor contemplou a adsorção para ambos os íons foi o pH 7,0, tendo o Pb(II) demonstrado maior capacidade de retenção. Em pH 2,0 houve maior retenção do Hg (II), já em pH 10,0 o Pb(II) obteve maior retenção. Indicando que o meio influencia diretamente na competição dos íons metálicos pelos sítios ativos. Constatou-se que a retenção do metal é robusta e estável ao longo de 6 meses. Os resultados indicam que a Cupriavidus metallidurans (CH34/pCM3) pode ser uma boa opção para biossorção de íons metálicos por meio de biorreator.<br>Dissertação (Mestrado em Tecnologia Nuclear)<br>IPEN/D<br>Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
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González, Núñez Raquel. "Ús de residus no perillosos i aluminosilicats per a la remediació de sòls contaminats amb metalls pesants." Doctoral thesis, Universitat de Barcelona, 2014. http://hdl.handle.net/10803/285297.
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El sòl és un recurs no renovable a curt i mitjà termini ja que els processos que generen un sòl són extremadament lents i requereixen de milers d’anys. A més a més, no és un sistema aïllat, sinó que presenta interaccions dinàmiques amb la geosfera, l’atmosfera i la hidrosfera, per la qual cosa està exposat a l’entrada de contaminants a través de moltes fonts de contaminació. L’origen dels metalls pesants en els sòls, que pot ser geogènic i antropogènic, marca el nivell de concentració, la forma química i la mobilitat a la qual es troben. La contaminació per metalls pesants en sòls presenta un problema a causa de la seva persistència en el medi, ja que no es degraden. Per tant, la seva presència en sòls s’ha anat incrementant des dels inicis de la revolució industrial. Els metalls pesants més comuns en el sòl són el Pb, Zn, Cd i Cu, i l’As com a metal•loide, i la forma química en la que es troben influencia la seva solubilitat, mobilitat i toxicitat en els compartiments ambientals i a la cadena tròfica. La consideració d’un sòl com a contaminat comporta desenvolupar i aplicar actuacions de recuperació ambiental de l’emplaçament. En nombrosos casos, les intervencions per tractar la contaminació de sòls per metalls pesants es basen en l’addició de materials, el que permet augmentar la retenció dels contaminants i diluir la concentració dels mateixos en les mescles sòl+material resultants, amb la finalitat de fer menys accessible el metall pesant a les plantes i evitar la possible contaminació a altres compartiments ambientals i a la cadena tròfica.
En base a aquesta problemàtica, la present tesi s’ha estructurat de la següent manera:
Primerament, es va fer una comparació de mètodes analítics, prèvia validació, per a la determinació del contingut total d’elements en mostres inorgàniques d’interès ambiental entre diferents tècniques d’anàlisi directa (FRX i µFRX), i mètodes basats en una digestió humida (Aigua Règia i microones) seguida d’una quantificació amb ICPOES i ICP-MS (detallat en la secció 2.1). Sent la digestió amb microones, combinada amb la mesura per una tècnica òptica adient, el millor mètode per a la determinació, tant d’elements majoritaris com traces, en matrius ambientals inorgàniques.
També es van avaluar els tests de lixiviació per a predir la mobilitat de metalls pesants en mostres ambientals emprant tests basats en extraccions simples fent servir diferents agents extractants, tals com 0,01 M i 1M CaCl2, 0,43 M CH3COOH i 0,05 M EDTA i el test de lixiviació Influència del pH sobre la lixiviació amb addició inicial d’àcid/base (pHstat) (detallat en la secció 2.2). Tot i que la fracció extraïble dels metalls amb EDTA va ser major que la obtinguda en el punt de pHstat equivalent, comparant aquest valor amb el punt de pH més àcid del pHstat, es va observar que aquest últim era el que donava la lixiviació màxima dels metalls i per tant, permet estimar la fracció mòbil màxima de metall a llarg termini.
Finalment es va establir una metodologia de laboratori per a la selecció de materials per la immobilització de metalls pesants en sòls contaminats (detallat en la secció 2.3). Sent els materials amb una elevada capacitat de neutralització àcida i/o capacitat de sorció específica els més prometedors els més adients en ésser addicionats per a la remediació de sòls contaminats amb metalls pesants. Aquesta metodologia es va aplicar per avaluar l’eficiència de l’addició dels materials en un estudi a escala de planta pilot (detallat en la secció 2.4), on es van corroborar els resultats obtinguts prèviament a escala de laboratori.<br>Metal pollution in soils requires intervention actions to attenuate its impact. In-situ remediation of contaminated soils is recently receiving increasing attention since it is a more feasible and economically affordable approach than ex-situ strategies, especially when facing a large amount of soil to be remediated. In this context, the addition of materials, including non-hazardous wastes to contaminated soils may be a suitable remediation strategy due to a double mechanism: decrease in pollutant mobility and dilution of pollutant concentration (if large material doses are used). Candidate materials must ensure an increase in the pollutant-soil interaction by increasing the pollutant sorption in the resulting mixture and/or by modifying soil properties governing the leaching and related transport of the pollutants into groundwaters and trophic chain. Moreover, another indirect benefit from this remediation strategy is that it may allow the reuse of non-hazardous wastes generated by industrial processes.
In order to give response on this lack of research, the thesis has been divided in the following parts:
Firstly, it has done a comparison of analytical methods, previously validated, to determine the total content of elements in inorganic samples of methods that directly analyze samples without digestion (XRF and µXRF) and methods based on a previous wet digestion (Aqua Regia and Microwaves) followed by quantification with ICP-OES and ICP-MS (detailed in section 2.1). The microwave digestion was the best method to determine the total content of major and trace elements in inorganic environmental matrices.
Also, it has done an evaluation of lixiviation tests to predict the mobility of heavy metals in environmental samples using simple extraction, 0,01 M and 1M CaCl2, 0,43 M CH3COOH and 0,05 M EDTA and the lixiviation test Influence of pH on leaching with initial acid/base addition (pHstat) (detailed in section 2.2). The EDTA extraction yield of metals was higher than pHstat, at the same pH, but if we compare with the most acidic pH of pHstat, we observed that the metal lixiviation was maxim, so the pHstat can estimate the maximum mobile fraction of the metal in a long period.
Finally, it has done the establishment of the laboratory methodology to select the materials to immobilize the heavy metals in contaminated soils (detailed in section 2.3). The best candidates were those with a high acid neutralization capacity and/or specific sorption capacity. This methodology was applied in order to evaluate the efficiency of the materials in a pilot plant study (detailed in section 2.4). The results obtained in a pilot plant corroborated the results obtained in a laboratory scale.
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Venegas, Sepúlveda Andrea. "Evaluación de la adición de materiales de origen orgánico para la remediación de suelos contaminados con metales pesados." Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/292729.
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El objetivo general de la presente tesis fue la evaluación de la adición de enmiendas de origen orgánico para la inmovilización de metales pesados en suelos contaminados. Se caracterizaron ocho materiales: un compost generado a partir de residuos orgánicos municipales (MOW), un compost de origen doméstico (DOM), un material compostado producido con residuos sólidos urbanos (MSW), un material compuesto por residuos vegetales (GW), dos materiales derivados de la industria del aceite de oliva (OWH y OP) y dos biochars (BF y BS). Se determinaron propiedades relevantes para la disponibilidad de los metales pesados en suelos, como el pH, capacidad de neutralización ácida (ANC), contenido de materia orgánica en la fase sólida y en solución, etc. Además del análisis estructural (FTIR y 13C-NMR), se evaluó su capacidad de sorción de metales pesados (Cd, Cu, Ni, Pb y Zn), mediante la determinación del coeficiente de distribución sólido-líquido (Kd) a concentraciones crecientes de metal, y posterior ajuste de las isotermas de sorción a modelos de Freundlich y lineal. A partir de los resultados en cuanto a ANC, pH y capacidad de sorción, se seleccionaron MOW, GW, BF y BS como los materiales más idóneos para la inmovilización de metales pesados en suelos contaminados.
Se evaluó la viabilidad del modelo NICA-Donnan para predecir las isotermas de sorción de algunos materiales orgánicos y de un suelo orgánico. Utilizando los parámetros de sorción genéricos, se observó que las isotermas de sorción predichas por el modelo para los materiales discreparon de los datos experimentales, con alguna excepción para el caso de Cu. Esta discrepancia fue atribuida a la baja concentración y al bajo grado de estabilización de las sustancias húmicas presentes los materiales. En cambio, las isotermas predichas para el suelo orgánico coincidieron con los datos experimentales, especialmente para Cd, Cu y Zn. El proceso de optimización para el suelo orgánico permitió obtener isotermas que se ajustaron de forma excelente con los datos experimentales y demostró que algunos parámetros variaron hasta dos órdenes de magnitud respecto a los valores genéricos iniciales.
Los cuatro materiales seleccionados en la primera fase de la tesis fueron utilizados para enmendar cinco suelos contaminados de características contrastantes en cuanto a pH, ANC, carbono orgánico disuelto (DOC) y contenido total y extraíble de los metales. Se realizaron ensayos de lixiviación de metales en un amplio intervalo de pH. En paralelo, las mezclas también fueron caracterizadas en cuanto a pH, ANC y DOC. Las reducciones más importantes de metal extraíble se observaron en aquellos suelos con menor pH y ANC inicial, enmendados con materiales de elevada ANC y pH. En algunos casos, se observó el posible rol adicional del aumento de la capacidad de sorción sobre la disminución de la lixiviación producto de la adición de enmiendas.
Finalmente, se evaluó la estabilidad de las enmiendas una vez adicionadas a los suelos contaminados. Se prepararon mezclas con tres suelos contaminados y tres enmiendas. Las muestras se sometieron a ciclos de secado y mojado sucesivos para acelerar el envejecimiento. Durante el tiempo de envejecimiento se determinaron las propiedades fisicoquímicas relevantes de las muestras, tales como pH, ANC, DOC y capacidad de sorción. El proceso de envejecimiento no comportó cambios significativos en ninguna de las propiedades clave de la interacción suelo/enmienda-metal. El mayor efecto en la inmovilización de metales se produjo inmediatamente después de la adición de las enmiendas y se mantuvo hasta el final de experimento. De este modo, el efecto de las enmiendas sobre las propiedades fisicoquímicas y la lixiviación de metales en los suelos fue persistente en el tiempo.<br>The aim of this work was the evaluation of the addition of organic wastes and biochars for the immobilisation of heavy metals in contaminated soils. Eight materials were tested: a compost derived from organic waste (MOW), a compost derived from food leftovers (DOM), a compost derived from municipal solid waste (MSW), a green waste material (GW), two biochars (BF and BS) and two by-products from the olive oil industry (OP and OWH). Key physicochemical properties for the immobilisation of heavy metals were evaluated, such as pH, ANC, TOC and DOC. The sorption capacity of metals (Cd, Cu, Ni, Pb and Zn) was evaluated by means of the determination of the solid-liquid distribution coefficient (Kd). The obtained isotherms were fitted to Freundlich and linear models. From pH, ANC and sorption capacity results, MOW, GW, BF and BS were selected as the best materials for the immobilisation of heavy metals in contaminated soils.
The viability of NICA-Donnan model for the prediction of sorption isotherms for some of the tested materials and an organic soil was evaluated. Sorption isotherms calculated from the generic parameter set of the model were in disagreement with respect to materials. This disagreement was related to the low organic matter content and low stabilization of organic matter in the materials. On the other hand, predicted isotherms for the organic soil were in agreement with experimental data, especially for Cd, Cu and Zn. Parameter optimisation for the organic soil resulted in sorption isotherms that accurately fitted to experiment, with some parameters that differed up to two orders of magnitude from generic parameters.
Four materials were employed to amend five contaminated soils with differing physicochemical properties in terms of pH, ANC, DOC, total and water soluble metal content. Leaching experiments were performed on the mixtures in a broad pH range. Samples were also characterized with respect to pH, ANC and DOC. Most important reductions in metal leaching were observed in soils with low pH and ANC amended with materials with high pH and ANC. In some cases, the effect of sorption capacity on the reduction of metal leaching was also observed.
Finally, the stability of amendments was evaluated in soil+amendment mixtures by means of drying-wetting cycles to accelerate aging. Relevant physicochemical properties remained constant until the end of the experiment. The largest effect on metal immobilization was observed immediately after amendment addition, while the effect of aging was minor. In this way, tested amendments have proven to be stable during aging period.
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Jablonski, Lukasz. "Versuche zur Phytoremediation von schwermetallbelasteten Böden und Verwertung der beladenen Pflanzenreste durch alkoholische Gärung." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-178430.
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Diese Arbeit hat das Ziel zu prüfen, inwieweit Energiepflanzen, die zur Erzeugung von Bioethanol verwendet werden sollen, für eine Phytoremediation SM-kontaminierter Flächen geeignet sind. In den durchgeführten Arbeiten wurden Topinambur/Kartoffel (Knollen-pflanzen), Zuckerrübe und Winterroggen auf SM/R- haltigem Boden angebaut und die Abhängigkeit des Pflanzenwachstums und der SM-Aufnahme von den SM/R- Konzentrationen, den pH- Bedingungen und der Zugabe verschiedener Zuschlagsstoffe (zur Verbesserung der Bodenbedingungen und des Pflanzenwachstums) untersucht. Anschließend wurden Gärversuche zur Erzeugung von Bioethanol mit den belasteten Pflanzenresten durchgeführt. Weiterhin wurde auch eine Bilanzierung des Verbleibs von Schwermetallen in den verschiedenen Produkt- und Abproduktströmen durchgeführt.
Um die Praktikabilität dieses Verfahrens zu untersuchen, wurde am Ende dieser Arbeit eine Energiebilanz durchgeführt sowie die Wirtschaftlichkeit betrachtet. Eine solche Kopplung der Phytoremediation mit einer anschließenden Erzeugung von Bioethanol ist bisher noch nicht aus der Literatur bekannt. Im Laufe der Arbeiten und Versuche hat sich gezeigt, dass der Anbau von Kartoffeln, Roggen und Topinambur auch unter den vorhandenen Bodenbedingungen (niedriger pH-Wert, wenig verfügbarer Stickstoff und Phosphor) uneingeschränkt möglich ist. Die Erträge von Topinambur und Winterroggen waren am besten bei mineralischer Düngung, ohne eine Intervention im organischen Substanzgehalt und im pH-Wert des Bodens, aber nur durch ausreichende Düngung mit Stickstoff.
Die Vergärung aller Pflanzen verläuft unproblematisch, die Ausbeute aus 100 kg Rohstoff ist vergleichbar mit unkontaminiertem Pflanzenmaterial. Die Gärflüssigkeit aus der Vergärung aller Pflanzen und der feste Gärrest aus der Winterroggen- und Zuckerrübenvergärung lässt sich gesetzeskonform als Dünger nutzen. Der feste Gärrest aus der Kartoffel- und Topinamburgärung darf wegen einer Überschreitung der Grenzwerte von Cd und Ni nicht als Dünger verwertet werden. Er muss einer anderen Verwendung zugeführt werden (z.B. Verbrennung und Deponie).
Der beste Austrag von Metallen pro Hektar in einer Vegetationszeit kann mit Topinambur erreicht werden (5189 g Al, 568 g Ni, 18,6 g Cd und 2,1 g U). Das Energiegewinn/Energieeintrag-Verhältnis, wenn nur die Pflanzenteile, die Stärke oder direkt vergärbare Zucker enthalten, in Alkohol umgewandelt werden, überschritt im Fall der Kartoffel (1,13) und des Winterroggens (1,16) den Wert 1 und im Fall der Zuckerrübe wurde fast der Wert 1 erreicht. Ein monetärer Gewinn ist zu erzielen mit der Alkoholherstellung aus Zuckerrüben, Winterroggen und Kartoffeln. Den besten Gewinn gewährleisten die Zuckerrübe mit über 1000 €/ha und der Winterroggen mit 447 €/ha. Ein solches Verfahren kann einen Beitrag zur schonenden Rekultivierung schwermetall-kontaminierter Flächen leisten (Habitaterhaltung, geringere Hypotheken für zukünftige Generationen), die Kosten der gesamten Sanierung durch einen Erlös senken sowie einen Beitrag zur Erzeugung eines CO2-neutralen Energieträgers leisten.
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Adler, Anneli. "Accumulation of elements in Salix and other species used in vegetation filters with focus on wood fuel quality /." Uppsala : Dept. of Crop Production Ecology, Swedish University of Agricultural Sciences, 2007. http://epsilon.slu.se/200706.pdf.
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Cherrad, Semcheddine. "Étude de la réponse adaptative du champignon filamenteux Botrytis cinerea à différents stress métalliques." Thesis, Lyon 1, 2011. http://www.theses.fr/2011LYO10182.
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De nombreux métaux sont indispensables au métabolisme cellulaire, d’autres sont considérés toxiques même à de faibles concentrations. Différents champignons appartenant à des différents groupes taxonomiques ont été identifiés dans des milieux pollués et ont révélé une capacité à survivre et à croître en présence de concentrations potentiellement toxiques. Pour s'adapter à ce stress, les champignons ont développé plusieurs mécanismes au niveau intracellulaire et extracellulaire. En particulier, ils sont connus pour leur capacité à sécréter un large panel de protéines. Cependant, leur rôle dans l'adaptation des champignons à la toxicité des métaux n'a pas encore été étudié. Pour répondre à cette question, le champignon Botrytis cinerea a été soumis à un stress métallique en présence de cuivre, zinc, nickel ou cadmium, les protéines sécrétées ont été collectées et séparées par 2D-PAGE. Deux métabolites ont également été analysés, l'acide oxalique et la nicotianamine. Enfin, les capacités de biosorption des champignons isolés à partir de sols pollués ont été étudiées. L'analyse du sécrétome a révélé 116 spots dont le volume varie en réponse d'au moins un métal. Cinquante-cinq de ces spots sont associés à des protéines uniques. La classification fonctionnelle de ces protéines a révélé que la production d'oxydoréductases et des enzymes dégradant la paroi cellulaire a été modifié en réponse aux métaux. L’étude de la production d'acide oxalique par Botrytis cinerea en réponse aux métaux montre une induction de la sécrétion d'oxalate en réponse au Zn et une accumulation de la nicotianamine, métabolite intracellulaire capable de fixer les métaux chez les plantes. Le gène de la nicotianamine synthase, est d’ailleurs surexprimé en présence de Cu, Zn et Ni. Plusieurs espèces fongiques ont été isolées à partir de sols pollués par des métaux, parmi ceux-ci Trichoderma asperellum et Zygorrhynchus moelleri montrent les meilleurs capacités de biosorption (10mg de Cu/g de matière sèche) des ions Cu<br>Metal ions are essential elements in many cellular processes. However, metal excess becomes toxic and constitutes a global environmental hazard. A range of fungi from all major taxonomic groups were found in metal-polluted habitats and the ability to survive and grow in the presence of potentially toxic concentrations is frequently encountered. To adapt to this stress, fungi have evolved several mechanisms at both intracellular and extracellular levels. In particular, fungi are well known for their ability to secrete a large panel of proteins. However, their role in the adaptation of fungi to metal toxicity has not yet been investigated. To address this question, here, the fungus Botrytis cinerea was challenged to copper, zinc, nickel or cadmium stress and secreted proteins were collected and separated by 2D-PAGE. Two metabolites were also analyzed, oxalic acid and nicotianamine. Finally, biosorption capacities of fungi isolated from polluted soils were investigated. Secretome analysis revealed one hundred and sixteen spots whose volume varied in at least one tested condition were observed on 2D gels. Fifty-five of these spots were associated with unique proteins and functional classification revealed that the production of oxidoreductases and cell-wall degrading enzymes was modified in response to metals. Study of oxalic acid and nicotianamine (NA) production by Botrytis cinerea in response to tested metals reveal that Zn induces oxalate secretion and that NA synthase gene is upregulated in presence of Cu, Zn and Ni. Many fungal species were isolated from metal polluted soils among them Trichoderma asperellum and Zygorrhynchus moelleri which show the maximum biosorption capacities of Cu ions
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Tellez, Rodriguez Carlos Mario 1967. "Studies of metal affinity interactions in metal recovery and bioremediation." Diss., The University of Arizona, 1997. http://hdl.handle.net/10150/288710.
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The primary goal of this dissertation project has been the study of metal affinity interactions in metal recovery and bioremediation. During the first part of this research a mathematical model that describes the affinity partitioning of metal ions in aqueous two-phase systems was derived. The model has been used to calculate complex formation constants between metal ions in solution and affinity ligands, satisfactorily describing their partition behavior. Simulation using this model shows the great effect that pH has on the partitioning of metal ions suggesting better conditions for the separation. Work on metal affinity interactions has led to the pursuit of characterization studies of metal uptake by microorganisms of relevance in bioremediation. The methanotrophic bacterium M. trichosporium 0B3b a mutant culture (PP358) that expresses soluble methane monooxygenase (sMMO) independent of the external copper concentration have been the subject of this research. Knowledge of substances and/or mechanisms that are involved in the copper uptake by M. trichosporium 0B3b will greatly facilitate application of this or like species to the bioremediation of hazardous waste. Specifically, the role of an extracellular copper-binding biochelator (CBL) in copper uptake by Methylosinus trichosporium 0B3b has been investigated. Experiments included the identification and physical characterization of the biochelator and elucidation of the environmental factors that affect its production. The biochelator is apparently an aromatic, low-molecular weight, hydrophobic molecule with high affinity and selectivity for copper. Results indicate that the mutation in PP358 is unrelated to possible defects in biochelator functionality and strongly suggest that the CBL is directly involved in the copper acquisition mechanism of this methanotroph. Finally, an existing colorimetric method currently used in the qualitative determination of sMMO has been modified and improved to provide additional quantitative information. Until now, the instability of one of the products of the reaction on which the current method is based has precluded the effective use of the assay as a quantitative tool. Stabilization of the compound of interest has been achieved, allowing the successful quantification of sMMO activity from M. trichosporium 0B3b and propane monooxygenase activity from the propane oxidizer M. vaccae JOB5.
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Ibuot, Aniefon. "Evaluation of the use of algae for bioremediation of toxic metal pollutants." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/evaluation-of-the-use-of-algae-for-bioremediation-of-toxic-metal-pollutants(db60de2c-ff75-4ece-b3a0-b67655bcadbb).html.
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Metal pollution has been a great challenge in most industrialized countries as a result of waste generated from industrial activities being introduced into the environment. Unicellular green algae have been considered a potential biological tool for bioremediation of metal pollutants due to its metal sequestration properties. However, methods for further improving unicellular green algae metal sequestration by manipulating metal uptake and tolerance in unicellular green algae have not been studied in detail. In this study, a family metal transport protein named MTP1 - MTP4 from C. reinhardtii were screened by yeast heterologous expression for metal transport activity. MTP1 was able to strongly rescue the Zn and Co sensitivity of the zrc1cot1 strain, MTP3 could weakly mediate Zn and Co growth, but MTP2 and MTP4 appeared to have no Zn or Co tolerance activity. MTP2, MTP3 and MTP4 but not MTP1 could strongly rescue the Mn sensitivity of the pmr1 strain. When MTP4 was over-expressed in C. reinhardtii the strain showed a significant increase in Cd tolerance compared to the wild type, but no significant difference in Mn tolerance and uptake. AtHMA4 a Zn2+ and Cd2+ transporter from the plant Arabidopsis thaliana, which is a member of the Heavy Metal ATPase family, was also expressed in C. reinhardtii. HMA4 full length and C-terminal tail expression strains were screened for Zn and Cd tolerance and uptake. Both sets of strains showed a significant increase in Cd and Zn tolerance and uptake compared to the wild type. Metal tolerance and uptake was compared between the genetically engineered C. reinhardtii strains and unicellular green algal strains that are naturally adapted to metal tolerance which were P. hussi, P. kessleri, and C. luteoviridis. Results showed significant increase in Zn and Cd tolerance and uptake in the natural strains compared to the engineered strains. Therefore in addition to genetically engineered strains, naturally adapted strains could also be used as tools for effective metal bioremediation and pollutant treatment.
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Barclay, Michelle. "Biodegradation of cyanide and its metal complexes by Fusarium solani." Thesis, University of Kent, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245625.
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Krinks, John K. "Microbial Assessment of a Bioremediation System Treating Acid Mine Drainage." Ohio University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1181069690.
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Jackson, Vanessa Angela. "Investigation into the metal contamination of three rivers in the Western Cape and the subsequent application of a bioreactor system as remediation technology." Thesis, [S.l. : s.n.], 2008. http://dk.cput.ac.za/cgi/viewcontent.cgi?article=1023&context=td_cput.
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Acharya, Lok P. "Chemical and Physical Characteristics of Mahoning River Sediment Before and After Fungal Bioremediation." Youngstown State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1211558693.
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Lavezzo, Letícia Fernanda. "Remediação de latossolo vermelho eutroférrico contaminado com mercúrio /." Jaboticabal, 2019. http://hdl.handle.net/11449/191135.
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Orientador: Wanderley José de Melo<br>Resumo: O mercúrio (Hg) é um metal potencialmente tóxico e não essencial para os organismos. Alternativas menos onerosas e ambientalmente corretas como a remediação com uso de plantas e bactérias podem recuperar áreas contaminadas. Por isso, avaliou-se, em ambiente controlado, o potencial de remediação de plantas e bactérias em Latossolo Vermelho eutroférrico (LVef) contaminado com HgCl2 em diferentes doses de Hg2+. Na primeira etapa, 5 kg de LVef foram contaminados com solução de HgCl2, em delineamento inteiramente casualizado com 4 tratamentos: controle positivo (sem Hg2+) e tratamentos com 5 mg kg-1 de Hg, 24 e 36 mg kg-1 de Hg2+, base seca, em 5 repetições e mantidos por 75 dias com plantas Hibiscus cannabinus para avaliar seu efeito remediador. A quantificação do Hg total foi por espectrofotometria de absorção atômica. O tratamento com 24 mg kg-1 de Hg apresentou fitomassa seca da raiz maior que dos demais. De modo geral, LVef foi responsável por reter maior concentração do Hg do que as plantas. O Hg acumulou em maior proporção nas raízes do que na parte aérea, sendo maior o acúmulo com aumento da dose. A planta que recebeu a dose de 36 mg kg-1 Hg acumulou 2,57 mg kg-1 de Hg por planta, diferindo dos demais tratamentos. Concluiu-se que o LVef adsorveu maior concentração de Hg do que as plantas. O H. cannabinus apresentou resistência a diferentes concentrações de Hg no solo e pode ser considerado como planta potencial estabilizadora de Hg2+, pois acumulou maior concentração de Hg... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: Mercury (Hg) is a potentially toxic metal and not essential for organisms. Less costly and environmentally sound alternatives such as plant and bacterial remediation have been used to recover contaminated areas. Therefore, in a controlled environment, the potential for remediation of plants and bacteria in an Oxisol contaminated with HgCl2 at different doses of Hg2+ was evaluated. In a first experiment, 5 kg of Oxisol were contaminated with HgCl2 solution, in a completely randomized design with 4 treatments: positive control (without Hg2+) and treatments with 5 mg kg-1 Hg, 24 and 36 mg kg-1 Hg2+, dry basis, and 5 repetitions and maintained for 75 days with Hibiscus cannabinus plants to assess its remediation potential. Total Hg quantification was by atomic absorption spectrophotometry. The 24 mg kg-1 Hg treatment presented higher root dry weight than the others. In general, LVef was responsible for retaining higher Hg concentration than plants. Hg accumulated to a greater extent in the roots than in the shoots, with greater accumulation with increasing dose. Plant that received the dose 36 mg kg-1 Hg accumulated 2,57 mg kg-1 Hg per plant, differing from the other treatments. It was concluded that Oxisol adsorbed higher Hg concentration than plants. H. cannabinus showed resistance to different soil Hg concentrations and can be considered as a potential Hg2+ stabilizing plant because it accumulated higher Hg concentration in the roots than in the shoots. In the second experimen... (Complete abstract click electronic access below)<br>Doutor
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Selenska-Pobell, Sonja, and Heino Nitsche. "Bacterial-Metal/Radionuclide Interaction: Basic Research and Bioremediation-Extendet Abstracts, Eurokonference, Forschungszentrum Rossendorf, December 2-4, 1998: Bacterial-Metal/Radionuclide Interaction: Basic Research and Bioremediation-Extendet Abstracts, Eurokonference, Forschungszentrum Rossendorf, December 2-4, 1998." Forschungszentrum Rossendorf, 1999. https://hzdr.qucosa.de/id/qucosa%3A21880.
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