Academic literature on the topic 'Bacteria. Flocculation'
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Journal articles on the topic "Bacteria. Flocculation"
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Ugbenyen, Anthony M., John J. Simonis, and Albertus K. Basson. "Screening for Bioflocculant-Producing Bacteria from the Marine Environment of Sodwana Bay, South Africa." Annals of Science and Technology 3, no. 1 (June 1, 2018): 16–20. http://dx.doi.org/10.2478/ast-2018-0010.
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AbstractFlocculants are chemicals that mediate flocculation process, by aggregating colloids from suspension to form floc. Chemical flocculants are hazardous to the environment, which inform the search for safer and eco-friendly alternatives from microorganisms. Bacterial strains were isolated from water and sediment samples collected from Sodwana Bay, South Africa, and physiological properties of the bacterial strains were observed. Flocculation test using kaolin clay suspension was done on all isolates and the ones that showed flocculating activity were identified molecularly using 16 rRNA gene sequence analysis. Forty marine bacteria isolates were gotten from sediments and water samples collected from Sodwana Bay. Most of the isolates exhibited a range of colony pigmentation (pink, creamy, yellow, and white). After purification of individual isolates, they were screened for their potential to produce bioflocculant. The result revealed that isolates marked SOD3, SOD10, SOD12, SOD26, SOD27, SOD28, SOD32, SOD33 and SOD34 produced bioflocculants as shown by the flocculating activities from their crude extract. All these isolates showed good flocculation of kaolin clay suspension above 60% (flocculating activity) except SOD12. These bioflocculant producing isolates were identified asPseudoalteromonas sp,Alcaligenes faecalis,Bacillus subtilis,Bacillus cereus,Bacillus stratosphericus. The results showed Sodwana Bay, South Africa as a reservoir of bacteria with potential to produce flocculants. However, further studies on the optimisation of culture conditions for bioflocculant production, extraction, characterisation and application of isolates is on the way to underscore the biotechnological importance of these microbes as producers of substitutes to harmful chemical flocculants commonly used in water and wastewater treatment.
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Wang, Xin Xin, Liang Wu, Ping Zhou, Chen Li, Li Bin Zhao, Wei An, and Yu Chen. "Harvesting of Polycyclic Aromatic Hydrocarbons (PAHs)-Degrading Bacteria by Magnetic Flocculation." Applied Mechanics and Materials 665 (October 2014): 563–66. http://dx.doi.org/10.4028/www.scientific.net/amm.665.563.
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Magnetic flocculation was reported to be efficient to harvest microalgae. However, little is known about the recovery of PAHs-degrading bacteria from the culture by magnetic flocculation.Advenella kashmirensisstrain w13003, a PAHs-degrading bacterium, was harvested by magnetic flocculation using magnetite and polyferric sulphate (PFS) as flocculants. The results showed the treatment with magnetite and PFS showed high concentration factor with flocculation efficiency near 100%, which suggest magnetic flocculation could result in a high concentration factor without significantly loss of PAHs-degrading bacteria. This is the first report about the recovery of PAHs-degrading bacteria by magnetic flocculation, which suggest its potential in bacterial harvesting.
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Prombutara, P., and M. S. Allen. "Flocculation-Related Gene Identification by Whole-Genome Sequencing of Thauera aminoaromatica MZ1T Floc-Defective Mutants." Applied and Environmental Microbiology 82, no. 6 (December 28, 2015): 1646–52. http://dx.doi.org/10.1128/aem.02917-15.
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ABSTRACTThauera aminoaromaticaMZ1T, a floc-forming bacterium isolated from an industrial activated-sludge wastewater treatment plant, overproduces exopolysaccharide (EPS), leading to viscous bulking. This phenomenon results in poor sludge settling and dewatering during the clarification process. To identify genes responsible for bacterial flocculation, a whole-genome phenotypic-sequencing technique was applied. Genomic DNA of MZ1T flocculation-deficient mutants was subjected to massively parallel sequencing. The resultant high-quality reads were assembled and compared to the reference genome of the wild type (WT). We identified nine nonsynonymous mutations and one nonsense mutation putatively involved in EPS biosynthesis. Complementation of the nonsense mutation located in an EPS deacetylase gene restored the flocculating phenotype. The Fourier transform infrared (FTIR) spectra of EPS isolated from the wild type showed a reduced C=O peak of theN-acetyl group at 1,665 cm−1compared to the spectra of MZ1T floc-deficient mutant EPS, suggesting that the WT EPS was partially deacetylated. Gene expression analysis also demonstrated that the putative deacetylase gene transcript increased before flocculation occurred. These data suggest that targeting deacetylation processes via direct chemical modification of EPS or enzyme inhibition may prove useful in combating viscous bulking in this and related bacteria.
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Okano, Chigusa, Koki Chiba, Eri Nasuno, Ken-ichi Iimura, and Norihiro Kato. "Complex Flocculation of Biofilm-forming Bacteria in the Presence of Flocculating Bacteria Isolated from Activated Sludge." Transactions of the Materials Research Society of Japan 42, no. 3 (2017): 77–80. http://dx.doi.org/10.14723/tmrsj.42.77.
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Yang, Ming Yan, Feng Han, Jia Tian, Chao Sun, Xia Cui, and Mei Rong Han. "Screening of a Microbial Flocculant Producing Silicate Bacteria MT5-2 and its Flocculating Activity." Advanced Materials Research 599 (November 2012): 3–8. http://dx.doi.org/10.4028/www.scientific.net/amr.599.3.
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A microbial flocculant (MBF) producing silicate bacteria MT5-2 was isolated from different sources of samples by silicate selected medium. Its chemical composition, optimal flocculation conditions，flocculation characteristics and primary application were studied in this paper. The results showed that the flocculant was an extracellular polysaccharide, and its flocculation activity was mainly distributed in the fermentation broth. The optimal flocculation conditions were as follows: for the 100 mL kaolin suspension, flocculant dosage was 4mL, metal cation dosage was 1% of ZnCl2 3mL, pH 7.5. The flocculation activity can reach 95% under this condition. Application results showed that flocculant MT5-2 had better flocculation activity in several common suspensions, such as kieselguhr, bentonite, soil, active carbon and starch, compared with polyacrylamide and inorganic salt.
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Ogunlaja, A., B. J. Ibidunni, K. Oyende, and O. O. Ogunlaja. "Optimization of bioflocculant production by bacteria isolated from oil-polluted soil and fermented maize effluent." Ife Journal of Science 22, no. 2 (August 24, 2020): 201–10. http://dx.doi.org/10.4314/ijs.v22i2.18.
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This study involved isolation of bioflocculant producing bacteria from soil and waste water. The isolates were tested for flocculation activities and those deemed fit were identified and the optimal environmental conditions for bioflocculant production were also determined. Samples were collected from oil-contaminated soil in Redeemer's University and fermented maize waste water. Microbial isolation was done using standardmicrobiological methods and identification was done using morphology, biochemical and molecular method with universal primer for 16SrRNA gene. Environmental conditions (pH, Temperature and cations) and media composition (nitrogen and carbon sources) were altered to optimize bioflocculant production and activities. Percentage flocculating activities were determined and calculated using standard method. We also adjustedrevolution rate and standing time to determine the optimum conditions for flocculation activities. Two bioflocculant producing isolates (Bacillus cereus and Lysinibacillus fusiformis) from oil-polluted soil and two from fermented maize waste water (Bacillus thuringiensis and Bacillus tropicus) were obtained. Neutral pH, temperature o of 30 C and inclusion of CaCl were the best conditions for bioflocculant production in all isolates except for 2 Lysinibacillus fusiformis which was best with acidic pH condition. Maltose as the carbon source was the best for all isolates except Bacillus thuringiensis (fructose) and ammonium was the best nitrogen source for all isolates except Bacillus cereus (peptone). Although condition III showed optimum condition for flocculation activities, the percentage activities were generally lower than normal condition. The highest percentage flocculating activities o of 98% were by Bacillus cereus and Bacillus tropicus at 30 C, neutral pH and 1% (w/v) CaCl salt with soluble starch 2 and maltose as their carbon source respectively. These bacteria can be exploited for their use as flocculants in water treatment.
Keywords: Agro-residues; Bio-friendly; Bioflocculant; Contaminated soil; Optimization
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Bello, Antonio Roberto Crystal, Dejanira de Franceschi Angelis, and Roberto Naves Domingos. "Ultrasound efficiency in relation to sodium hypochlorite and filtration adsorption in microbial elimination in a water treatment plant." Brazilian Archives of Biology and Technology 48, no. 5 (September 2005): 739–45. http://dx.doi.org/10.1590/s1516-89132005000600009.
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Processes like ultrasound, chlorination and filtration-adsorption were compared to eliminate microorganisms and to adjust established parameters of public drinking water. A mini water treatment plant (WTP-CB), in pilot scale, was projected and built to evaluate each process influence as: decontamination, coagulation-flocculation, sedimentation and filtration. Total and fecal coliforms, Escherichia coli and heterotrophic bacteria and physic/chemical parameters were quantified from water. Ultrasound, chlorination and filtration-adsorption were efficient to inactivate and/or eliminate bacteria. Ultrasound decontamination in addition to coagulation-flocculation, sedimentation and filtration, could be considered as an alternative treatment water solution where prechlorination, coagulation-flocculation, sedimentation and filtration were used. The chlorination itself was efficient in inactivating bacteria despite of the coagulation-flocculation process; however, in the absence of the coagulation process, the resultant water did not achieve the established parameters. The filtration-adsorption was an important process to eliminate bacteria, showing that the filter retained particles, suspended solids, besides chemical substances and microorganisms.
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Sicchierolli, S. M., E. M. Mamizuka, and A. M. Carmona-Ribeiro. "Bacteria Flocculation and Death by Cationic Vesicles." Langmuir 11, no. 8 (August 1995): 2991–95. http://dx.doi.org/10.1021/la00008a024.
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Peng, X., J. Sun, D. Iserentant, C. Michiels, and H. Verachtert. "Flocculation and coflocculation of bacteria by yeasts." Applied Microbiology and Biotechnology 55, no. 6 (June 1, 2001): 777–81. http://dx.doi.org/10.1007/s002530000564.
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Haegeman, Bart, Claude Lobry, and Jérôme Harmand. "Modeling bacteria flocculation as density-dependent growth." AIChE Journal 53, no. 2 (2007): 535–39. http://dx.doi.org/10.1002/aic.11077.
Full textDissertations / Theses on the topic "Bacteria. Flocculation"
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Strand, Sabina P. "Interactions between Chitosans and Bacteria : Flocculation and Adhesion." Doctoral thesis, Norwegian University of Science and Technology, Faculty of Natural Sciences and Technology, 2001. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-108.
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Vilinska, Annamaria. "Bacteria-sulfide mineral interactions with reference to flotation and flocculation." Licentiate thesis, Luleå : Luleå University of Technology, 2007. http://epubl.ltu.se/1402-1757/2007/68/.
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Oladele, Agunbiade M. "Studies on bioflocculants produced by three freshwater Actinomycetes (Streptomyces Sp.Gansen, Cellulomonas Sp,Bola and Brachybacterium Sp, UFH) isolated from Tyume river." Thesis, University of Fort Hare, 2011. http://hdl.handle.net/10353/6550.
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Several bacteria were isolated from the bottom sediments of Tyume River and investigated for bioflocculant production potentials. Kaolin clay suspension (4 g/l) was used to measure the flocculating activity and three of the positive isolates were identified by 16S rRNA gene nucleotide sequence analyses and the sequences deposited in GenBank as Streptomyces sp Gansen (accession number HQ537129), Brachybacterium sp UFH (accession number HQ537131.), and Cellulomonas sp Bola (accession number HQ537132). Streptomyces sp Gansen exhibited its maximum flocculating activity using lactose (85% activity), peptone (76.3% activity), Ca2+ as sole sources of carbon, nitrogen and cations respectively, and at a neutral pH of 7.0, while, the bioflocculant produced by Brachybacterium sp UFH with glucose, urea and Ca2+ as carbon, nitrogen and cations sources yielded 82% and 97% flocculation activity respectively at a neutral pH. Also, glucose (73.2% activity), ammonium chloride (78.2% activity) and Ca2+ resulted in optimal production of bioflocculant by Cellulomonas sp Bola, also at a neutral pH. Chemical analysis confirmed that bioflocculant produced by Streptomyces Gansen is a polysaccharide while Brachybacterium sp UFH and Cellulomonas sp Bola produces a glycoprotein compound. This freshwater actinomycetes appears to have a tremendous potential as sou rces of new bioflocculants.
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Robinson, Philip Mark. "A quantitative investigation into the factors affecting the flocculation of bacteria (Escherichia coli) with cationic polyacrylamide." Thesis, Teesside University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.410864.
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Buttice, Audrey Lynn. "Aggregation of Sediment and Bacteria with Mucilage from the Opuntia ficus-indica Cactus." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4295.
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Flocculants are commonly used in industrial settings where solid-liquid separations are desired including industrial and municipal wastewater management and potable water production facilities. Conventional flocculants include inorganic metal salts and synthetic organic polymers. The cost, availability, and harmful effects of the non-biodegradable nature of these flocculants have led to the widespread study of natural flocculants. Current natural flocculants being studied include polysaccharides cultivated from microbial extracellular matrix products and plant based materials. In this study, the mucilage of Opuntia ficus-indica cactus was evaluated as a natural flocculant for sediments and bacteria. The O. ficus-indica cactus is also known as the nopal or prickly pear and is commonly used as a food source in Mexico and Latin America. Using simple extraction techniques non-gelling (NE) and gelling (GE) mucilage extracts were isolated from fresh cactus pads. Column tests were used to evaluate the flocculation and removal of suspended sediment and bacteria caused by mucilage addition. Throughout this work the mucilage's ability as a flocculant was evaluated by varying mucilage type and concentration, suspended contaminant type and concentration, and cation type and concentration. Many of the results are explained in terms of the morphology and chemical composition of the GE and NE mucilage extracts. The extracts consist primarily of polysaccharides and differences in physical structure between mucilage types were seen using atomic force microscopy and transition electron microscopy. A variety of suspended particles were used to evaluate the mucilage as a flocculant including kaolin,
acid-washed kaolin, and bacteria. The bacteria employed in this study include Bacillus cereus, Escherichia coli HB101 K12, and fully attenuated Bacillus anthracis Sterne strain. The addition of monovalent (Na+ and K+), divalent (Ca2+ and Mg2+), and trivalent (Al3+ and Fe3+) cations was studied alone and in combination with mucilage. In cation studies Ca2+ had the most profound effect on flocculation efficiency; therefore its efficacy was further explored. Mucilage was most effective with dosages between 5 and 50 mg/L for the contaminants studied. Using these optimal concentrations, 20 to 200 L of water could be treated with only 1 g of mucilage powder. Based on the extraction method used in this work, 1 g of mucilage can be obtained from a cactus pad weighing approximately 250 g (wet weight). Mucilage remained an effective flocculant over a wide range of suspended contaminant concentrations showing that mucilage is a versatile flocculant that can be tailored for a variety of applications. Overall, this work shows that the O. ficus-indica cactus is an effective flocculant for suspended sediments and bacteria. The cactus' low cost, abundance, and current use in many areas make it an attractive alternative to traditionally used flocculants. Additionally, this work builds upon existing knowledge pertaining to natural flocculants and could offer insight into their general behaviors for water treatment applications.
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Krapf, Marie-Ève. "Agrégation de cellules bactériennes par des polymères cationiques (polyéthylèneimine) : influence de la masse moléculaire du polymère et de la présence/absence de surstructures exopolymériques bactériennes sur la déshydratation des boues biologiques." Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0089/document.
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Après déshydration, les boues biologiques présentent en moyenne une siccité de 30%, ce qui pose d'importants problèmes environnementaux. Afin de comprendre les mécanismes physico-chimiques de rétention d'eau dans ces boues, nous les avons modélisées par une souche bactérienne pure présentant la particularité de produire ou non des surstructures, suivant sa température de culture. Les suspensions bactériennes ainsi obtenues ont été floculées par du polyéthylèneimine de différentes masses moléculaires. Des mesures de densité optique, mobilité électrophorétique, conductivité, pH, absorbance, granulométrie, ainsi que des observations en MET et AFM ont été effectuées. Cela nous a permis de caractériser la structure des agrégats ainsi obtenus et d'évaluer les influences relatives de la masse moléculaire du polymère ainsi que de sa concentration et de la présence/absence de surstructures sur l'agrégation de cellules bactériennes. Des mesures d'élasticité, de constante de raideur et de pression de turgescence ont été effectuées par spectroscopie de force, ce qui nous a permis de caractériser les propriétés nanomécaniques des agrégats. Dans un second temps, les suspensions floculées ont été déshydratées par centrifugation, procédé mis en oeuvre dans certaines station d'épuration. Des mesures d'élasticité et de viscosité (gradient de cisaillement infini) ont été effectuées par rhéologie. La corrélation de celles-ci avec des mesures de siccité nous a permis de conclure à un impact important des surstructures, de la masse moléculaire et de la concentration en polymère sur la déshydratation des boues biologiquesAfter dewatering, a biological sludge still contains an average water content of 70%, thus causing huge environmental problems. To achieve a better understanding of the mechanisms underlying physicochemical interactions inducing water retention in the sludge, the bacterial sludge was modeled by a pure strain producing or not surface appendages, depending on the growth temperature. These bacterial suspensions were flocculated by polyethyleneimine of various molecular weights. Measurements of optical density, electrophoretic mobility, conductivity, pH, absorbance, particle size, as well as AFM and TEM observations were performed. This allowed to characterize aggregates structures and to estimate the influence of molecular weight and concentration of polymer and presence/absence of surface appendages. Measurements of elasticity, spring constant and turgor pressure were carried out by force spectroscopy allowing to characterize nanomechanical properties of aggregates. In a second step, a dewatering of these flocculated suspensions was performed by centrifugation, process used in some wastewater treatment plants. Measurements of elasticity and viscosity were carried out by rheology. Correlations with dryness measurements allowed to conclude that the presence/absence of surface appendages, and also the molecular weight and concentration of the polymer have a significant impact on biological sludge dewatering
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Kajornatiyudh, Sittiporn. "Bacterial extracellular polymers and flocculation of activated sludges." Diss., Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/52313.
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The extracellular polymers produced by bacteria play an important role in bacterial aggregation or bacterial flocculation in secondary waste treatment. The mechanisms responsible for this floc formation are thought to be polymer induced adsorption and interparticle bridging among bacterial cells or between bacterial cells and inorganic colloids. The efficiency of the processes following flocculation in the treatment line such as sedimentation, sludge thickening, and sludge dewatering depends on the extent of this bacterial flocculation.
In this research, sludge samples from under various substrate conditions were examined for type, molecular weight, physical characteristics„ and quantity of extracellular polymers so that the general characteristics of the various polymers could be established. An attempt was made to determine if a relationship exists between the state of bacterial aggregation and the polymer characteristics. This research also investigated the sludge physical properties. The effect of various parameters such as pH, divalent cation (mixture and concentration), and mixing (period and intensity) on dewatering properties were studied.
A major goal of this study was to develop a flocculation model for activated sludge. This model could be used to determine if plants can increase the efficiency of waste treatment and sludge thickening and sludge dewatering processes.Ph. D.
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Koivuranta, E. (Elisa). "Optical monitoring of flocs and filaments in the activated sludge process." Doctoral thesis, Oulun yliopisto, 2016. http://urn.fi/urn:isbn:9789526211794.
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Abstract Flocculation plays a critical role in the activated sludge process, where flocs are removed by settling and where unsatisfactory flocculation is resulting in poor effluent quality. Control and operation of the process is also challenging as it is sensitive to external and internal disturbances. Furthermore, stricter environmental demands are also being placed on wastewater treatment and discharge quality thus solutions are needed to improve the current systems. A novel optical monitoring method employing a tube flow and a CCD camera was developed to characterize the flocs and filaments of the sludge, and the method was tested on samples from full-scale activated sludge plants. An online device operating on the same principle was also developed and this was tested over a period of eight months at municipal wastewater treatment plant. Optical monitoring was employed in the laboratory to study the breakage of activated sludge flocs. Based on the image analysis data, in the industrial plant the major breakage process was large-scale fragmentation. In the two municipal plants, it was surface erosion. The flocs had more filaments and were more irregular in shape in the industrial plant, which could be the reason for the large-scale fragmentation. The effect of floc morphology on the effluent clarity of the activated sludge process was studied in the industrial and municipal activated sludge plants by optical monitoring over periods of three months and eight months, respectively. The changes in floc morphology took place slowly in both plants. Four major factors that correlated with the purification results were the size and shape of the flocs and the quantities of small particles and filaments. The image analysis results suggested that the settling problem that occurred during the test periods in the industrial plant was caused by dispersed growth, whereas that in the municipal plant was caused by filamentous bulking. In conclusion, it is possible to use the developed method online in order to analyse the state of flocculation. Thus the method could be useful when developing online monitoring applications for quantifying floc characteristics and for diagnosing the causes of settling problems in the wastewater treatment plantsTiivistelmä Aktiivilieteprosessissa flokkulaatiolla on merkittävä rooli, sillä muodostuneet flokit poistetaan prosessista laskeutuksen avulla. Siten huono flokkulaatio johtaa puhdistetun jäteveden kiintoainemäärän lisääntymiseen. Prosessin säätö ja operointi on kuitenkin hankalaa, sillä aktiivilieteprosessi on herkkä ulkoisille ja sisäisille häiriöille. Jätevedenpuhdistukseen liittyvät ympäristövaatimukset ja päästöehdot vesistöihin ovat myös tiukentuneet, joten uusia menetelmiä tarvitaan parantamaan nykyisiä prosesseja. Tässä työssä kehitettiin uusi, optinen kuvantamismenetelmä karakterisoimaan flokkeja ja rihmoja. Menetelmä hyödyntää putkivirtausta ja CCD-kameraa ja sitä testattiin aktiivilietelaitosten näytteillä. Lisäksi kehitettiin samaa periaatetta noudattava online-laitteisto, jota testattiin kahdeksan kuukauden ajan. Optista kuvantamista testattiin laboratoriossa flokkien hajoamistutkimuksessa. Kuva-analyysitulosten perusteella kahden kunnallisen aktiivilietelaitoksen flokit hajosivat pintaeroosioon perustuvan mallin mukaan ja teollisen aktiivilietelaitoksen flokit hajosivat fragmentaatiomallin mukaan. Teollisen aktiivilietelaitoksen flokeissa oli enemmän rihmoja ja ne olivat epäsäännöllisemmän muotoisia, mikä voi olla syynä flokkien fragmentaatioon. Flokkien morfologian vaikutus jäteveden puhdistustuloksiin tutkittiin teollisessa (kolmen kuukauden ajan) ja kunnallisessa (kahdeksan kuukauden ajan) aktiivilietelaitoksessa optisella kuvantamismenetelmällä. Molemmissa laitoksessa muutokset flokkien morfologiassa tapahtuivat hitaasti. Neljä tärkeintä tekijää, jotka korreloivat puhdistustulosten kanssa, olivat flokkien koko ja muoto sekä pienten partikkelien ja rihmojen määrä. Kuva-analyysitulosten perusteella laskeutumisongelma teollisessa jätevesilaitoksessa johtui flokinmuodostajabakteerien liian pienestä määrästä ja kunnallisessa jätevesilaitoksessa rihmamaisten bakteerien liikakasvusta. Yhteenvetona voidaan todeta, että kehitettyä menetelmää on mahdollista käyttää online-mittarina sekä sen avulla voidaan arvioida flokkulaation tilannetta. Siten menetelmää on mahdollista hyödyntää flokkien ominaisuuksien karakterisoinnissa ja arvioidessa jätevedenkäsittelylaitoksen laskeutumisongelmien aiheuttajaa
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Okaiyeto, Kunle. "Evaluation of flocculating potentials and charecterization of bioflocculants produced by three bacterial isolates from Algoa Bay, South Africa." Thesis, University of Fort Hare, 2016. http://hdl.handle.net/10353/2633.
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Flocculation has been widely adopted as one of the most effective methods to remove colloidal particles in water or wastewater treatment. Synthetic flocculants are conventionally used because of their high flocculating efficiency and cost-effectiveness. However, they have been reported to have hazardous properties and implicated in some serious health problems including senile dementia and neuro-toxicity, as well as being recalcitrant in the environment. Consequently, efforts are being geared away from the use of synthetic flocculants in water and wastewater treatment. Hence, the need for safe and eco-friendly flocculants has become imperative. Compared with synthetic flocculants, bioflocculants have special advantages such as safety, biodegradability and harmlessness to the environment and humans; attributes which make them potential alternatives in water treatment, downstream as well as fermentation processes. In the current study, the potentials of bacterial isolates recovered from Algoa Bay in the Eastern Cape Province of South Africa for bioflocculant production were investigated. The bacterial isolates were identified by polymerase chain reaction (PCR) as belonging to the Bacillus genus. The analysis of 16S ribosomal deoxyribonucleic acid (rDNA) nucleotide sequence of isolate M72 showed 99 percent similarity to Bacillus toyonensis strain BCT-7112 and was deposited in the GenBank as Bacillus toyonensis strain AEMREG6 with accession number KP406731. Likewise, the 16S rDNA nucleotide sequences of isolates M69 and M67 showed 98 percent sequence similarity to Bacillus licheniformis strain W7 and Bacillus algicola strain QD43 respectively; and M67 isolate was subsequently deposited in the GenBank as Bacillus sp. AEMREG7 with accession number KF933697.1. The results of the nutritional requirements and fermentation conditions revealed that optimum inoculum size for REG-6 production was 4 percent (v/v), while 5 percent (v/v) and 3 percent (v/v) were most favourable for MBF-W7 and MBF-UFH production respectively. Glucose was the best carbon source for the production of bioflocculants (REG-6 and MBF-UFH) by Bacillus toyonensis AEMREG6 and Bacillus sp. AEMREG7 respectively, while maltose supported optimum bioflocculant (MBF-W7) production by Bacillus specie. Inorganic nitrogen (NH4NO3) was the favoured nitrogen source for both REG-6 and MBF-W7 production, while mixed nitrogen sources [yeast extract + urea + (NH4)2SO4] supported the maximum production of MBF-UFH. The initial medium pH for REG-6 was 5, while MBF-W7 and MBF-UFH were both maximally produced at the initial pH of 6. After a 96 h cultivation period under optimal culture conditions, 3.2 g of purified REG-6 with a maximum flocculating activity of 77 percent was recovered from 1 L fermented broth of Bacillus toyonensis AEMREG6. Yields of 3.8 g and 1.6 g pure bioflocculants with the respective highest flocculating activities of 94.9 percent and 83.2 percent were also obtained from 1 L, 72 h-fermented broths of Bacillus licheniformis and Bacillus sp. AEMREG7 respectively. Furthermore, all the three bioflocculants (REG-6, MBF-W7 and MBF-UFH), displayed thermal stability within the temperature range of 50 to 100 oC, with strong flocculating activities of over 80 percent against kaolin suspension over a wide range of pH range (3–11) and relatively low dosage requirements of 0.1-03 mg/ml in the presence of divalent cations in the treatment of kaolin clay suspension and Thyme River waters. Chemical composition analyses of the bioflocculants showed them to be glycoproteins with a predominantly polysaccharide backbones as shown by the following carbohydrate/protein (w/w) ratios: 77.8 percent:11.5 percent (REG-6); 73.7 percent:6.2 percent (MBF-W7) and 76 percent:14 percent (MBF-UFH).
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Boltz, Joshua. "The Kinetics of Particulate Substrate Utilization by Bacterial Films." ScholarWorks@UNO, 2005. http://scholarworks.uno.edu/td/254.
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There is a need to develop a mathematical expression capable of describing the removal of particulate chemical oxygen demand (PCOD) from wastewaters in biological film systems. In this context, organic particles that are maintained in suspension (i.e., not removed during normal settling) are the focus of experimentation, modeling, and discussion. The goal of this research project is to study the kinetics of PCOD removal from wastewaters by bacterial films, or biofilms. To achieve this objective, a bench-scale rotating disc biofilm reactor (RDBR) was operated using methanol (dissolved substrate), Min-U-Sil 10 (inorganic particulates), and Maizena corn starch (organic particulates) dissolved/suspended in the influent stream. The effect of the ratio of biofilm area to volumetric flow rate passing through the RDBR on the concentration of substrate remaining in the final effluent was determined, and the kinetic relationship was established for both dissolved substrate and particle removal. Exocellular polymeric substances (EPS) were extracted and quantified in order to explain the role of biological flocculation, or bioflocculation, in particulate removal. In the literature, Fick's first law and zero-order kinetics have described the diffusion and biochemical reaction of soluble substrate within the bacterial film matrix (when completely penetrated), respectively. The present study confirms this kinetic behavior for various influent methanol concentrations. On the other hand, the removal of particulates, organic and inorganic, adheres to first-order reaction kinetics. These findings, coupled with the identification of EPS, attribute bioflocculation as the primary removal mechanism of particulates. A mass balance on the biofilm reactor allowed for the development of a comprehensive rate expression for substrate consumption by biofilms when both dissolved and particulate substrates are available. Total chemical oxygen demand (TCOD) is comprised of dissolved chemical oxygen demand (DCOD) and PCOD, each of which can be readily determined through laboratory analysis. An equation was developed that accurately describes the disappearance of TCOD by the bioflocculation of PCOD and consumption of DCOD in the bench scale RDBR.
Book chapters on the topic "Bacteria. Flocculation"
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Kasan, Nor Azman, Shaziela Mohamad Said, Nurarina Ayuni Ghazali, Nurul Fakriah Che Hashim, Zaharah Ibrahim, and Nakisah Mat Amin. "Application of Biofloc in Aquaculture: An Evaluation of Flocculating Activity of Selected Bacteria from Biofloc." In Beneficial Microorganisms in Agriculture, Aquaculture and Other Areas, 165–82. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-23183-9_8.
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Rastogi, Rupali. "Water Purification Using Different Chemical Treatment." In Advances in Environmental Engineering and Green Technologies, 338–67. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-6111-8.ch019.
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Water from surface sources is often contaminated by microbes, whereas groundwater is normally safer, but even groundwater can be contaminated by harmful chemicals from human activities or from the natural environment. The purification process of water may reduce the concentration of particulate matter including suspended particles, parasites, bacteria, algae, viruses, fungi, and a range of dissolved and particulate material derived from the surfaces. Water purification is the process of removing undesirable chemicals, materials, and biological contaminants from contaminated water. Most water is purified for human consumption (drinking water), but water purification may also be designed for a variety of other purposes, such as medical, pharmacology, chemical, and industrial applications. In general, the methods used include physical processes such as filtration and sedimentation, biological processes such as slow sand filters or activated sludge, chemical processes such as flocculation and chlorination, and the use of electromagnetic radiation such as ultraviolet light.
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Harrison, Roger G., Paul W. Todd, Scott R. Rudge, and Demetri P. Petrides. "Sedimentation." In Bioseparations Science and Engineering. Oxford University Press, 2015. http://dx.doi.org/10.1093/oso/9780195391817.003.0008.
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Sedimentation is the movement of particles or macromolecules in an inertial field. Its applications in separation technology are extremely widespread. Extremes of applications range from the settling due to gravity of tons of solid waste and bacteria in wastewater treatment plants to the centrifugation of a few microliters of blood to determine packed blood cell volume (“hematocrit”) in the clinical laboratory. Accelerations range from 1 × g in flocculation tanks to 100,000 × g in ultracentrifuges for measuring the sedimentation rates of macromolecules. In bioprocessing, the most frequent applications of sedimentation include the clarification of broths and lysates, the collection of cells and inclusion bodies, and the separation of fluids having different densities. Unit operations in sedimentation include settling tanks and tubular centrifuges for batch processing, continuous centrifuges such as disk centrifuges, and less frequently used unit operations such as field-flow fractionators and inclined settlers. Bench scale centrifuges that accommodate small samples can be found in most research laboratories and are frequently applied to the processing of bench scale cell cultures and enzyme preparations. Certain high-speed ultracentrifuges are used as analytical tools for the estimation of molecular weights and diffusion coefficients. The chapter begins with a description of the basic principles of sedimentation, followed by methods of characterizing laboratory and larger-scale centrifuges. Two important production centrifuges, the tubular bowl centrifuge and the disk-stack centrifuge, are analyzed in detail to give the basis for scale-up. Ultracentrifuges, important for analytical and preparative work, are then analyzed. The effect of flocculation of particles on sedimentation is presented, and sedimentation of particles at low accelerations is discussed. The chapter concludes with a description of centrifugal elutriation.
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Tuinier, R., and C. G. de Kruif. "DEPLETION FLOCCULATION OF CASEIN MICELLES INDUCED BY THE EPS OF A LACTIC ACID BACTERIUM." In Gums and Stabilisers for the Food Industry 9, 222–30. Elsevier, 1998. http://dx.doi.org/10.1533/9781845698362.3.222.
Full textConference papers on the topic "Bacteria. Flocculation"
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Kyoichi, Okamoto, Toyama Takeshi, and Komoriya Tomoe. "Development on Most Suitable Removal Method of Radioactive Cesium Adsorbed on Ocean Sludge by Using Fine Bubble and Activating Microorganisms." In ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/omae2017-62581.
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Fukushima nuclear accident of March 11, 2011, soil and water had been contaminated by radioactive cesium. Moreover, radioactive cesium was found in the ocean sludge in Tokyo Bay flowing from rivers. Cesium which is adsorbed to the sludge cannot be easily removed. One of the authors developed decomposition and purification system, a circulation-type system by fine bubbles, that is, by creating aerobic state, aerobic bacteria are activated resulting to decomposition and purification of ocean sludge. Based on the hypothesis that radioactive cesium is adsorbed on the surface of the sludge deposition. It is considered that cesium can be eluted after decomposing the deposited sludge. Once the cesium is eluted in the water, it can fix to a mineral such as zeolite. Eluting and fixing cesium adsorbed on sludge takes so much time. In this case, the concept of removing the left sludge by flocculation method and then followed by coagulating sedimentation method is studied. In this study, our objects are to show the effectivity and efficiency of using flocculation and coagulating sedimentation in removing radioactive cesium. As the results, we pointed out this method is very good.