Journal articles: 'Retention of heavy metals'

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Yong, Raymond N., Rosa Galvez-Cloutier, and Yuwaree Phadungchewit. "Selective sequential extraction analysis of heavy-metal retention in soil." Canadian Geotechnical Journal 30, no. 5 (October 1, 1993): 834–47. http://dx.doi.org/10.1139/t93-074.

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The selective sequential extraction method of analysis is used in this study to determine the distribution of heavy metals in some clay soils, to assist in evaluation of the role of the various clay soil solids (clay minerals, organics, amorphous materials, and carbonates) in heavy-metal retention capability as a function of acidity of the leachate. The chemical speciation model MINTEQ (metal speciation equilibrium model for surface and groundwater) is used to calculate the probable percent distribution of different species of heavy metals present in the leachate used. The selective sequential extraction method is based on the fact that different forms of heavy metals that are retained in soil (e.g., as oxides, hydroxides, carbonates, bound with organic matter) can be extracted selectively by using appropriate reagents. The results show that heavy metals can be retained in the four clay soils studied by several soil phases or mechanisms such as exchangeable, carbonate, hydroxide, and organic phases. The retention of heavy metals in any phase depends on soil solution pH, soil constituents, and the type of heavy metal. At high soil solution pH values, retention of heavy metal by precipitation mechanisms prevails, whereas at low soil solution pH, retention by cation exchange mechanisms becomes dominant. The results from the selective sequential extraction analysis support the conclusion of the significance of soil buffer capacity with regard to heavy-metal retention. The capacity of the soils to retain high amounts of heavy metals as they receive increasing amounts of acid (i.e., as the pH is reduced) depends directly on the soil initial pH values and on their buffer capacities. Key words : selective sequential analysis, exchangeable cations, heavy metals, equilibrium models, oxides.

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Scherer, U., S. Fuchs, H. Behrendt, and T. Hillenbrand. "Emissions of heavy metals into river basins of Germany." Water Science and Technology 47, no. 7-8 (April 1, 2003): 251–57. http://dx.doi.org/10.2166/wst.2003.0696.

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The input of seven heavy metals (Cd, Cr, Cu, Hg, Ni, Pb and Zn) into the large river basins of Germany via various point and diffuse pathways were estimated for the period of 1985 through 2000. To quantify the emissions via point sources a nationwide survey on heavy metal data of municipal wastewater treatment plants and industrial direct discharges was carried out. The input via diffuse pathways was calculated using an adapted version of the model MONERIS. This model accounts for the significant transport processes, and it includes a Geographical Information System (GIS) that provides digital maps as well as extensive statistical information. For a comparison of the calculated heavy metal emission with the measured heavy metal load at monitoring stations the losses of heavy metals due to retention processes within the river systems have to be considered. Therefore heavy metal retention was calculated according to the retention functions given by Vink and Behrendt. For the large river basins a good correspondence could be found between estimated and measured heavy metal loads in rivers. The total emission into the North Sea decreased for each metal during the period of 1985 to 2000. The reduction varies between 87% for Hg and 41% for Ni mainly caused by the decline via point sources. Today's emissions of heavy metals into river basins of Germany are dominated by the input via diffuse pathways. The most important diffuse emission pathways are “paved urban areas” and “erosion”.

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Rusanescu, Marin, Carmen Otilia Rusanescu, Gheorghe Voicu, and Mihaela Begea. "Applications of Bentonite to Soil Decontamination." Revista de Chimie 69, no. 7 (August 15, 2018): 1695–98. http://dx.doi.org/10.37358/rc.18.7.6397.

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A calcium bentonite from Orasu Nou deposit (Satu Mare Romania) was used as raw material. We have conducted laboratory experiments to determine the influence of bentonite on the degree of heavy metal retention. It has been observed that the rate of retention increases as the heavy metal concentration decreases. Experimental studies have been carried out on metal retention ( Zn) in bentonite. In this paper, we realized laboratory experiments for determining the influence of metal (Zn) on the growth and development of two types of plants (Pelargonium domesticum and Kalanchoe) and the effect of bentonite on the absorption of pollutants. These flowers were planted in unpolluted soil, in heavy metal polluted soil and in heavy metal polluted soil to which bentonite was added to observe the positive effect of bentonite. It has been noticed that the flowers planted in unpolluted soil and polluted with heavy metals to which bentonite has been added, the flowers have flourished, the leaves are still green and the plants whose soils have been polluted with heavy metals began to dry after 6 days, three weeks have yellowish leaves and flowers have dried. Experiments have demonstrated the essential role of bentonite for the removal of heavy metals polluted soil.

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Yong, Raymond N., and Yuwaree Phadungchewit. "pH influence on selectivity and retention of heavy metals in some clay soils." Canadian Geotechnical Journal 30, no. 5 (October 1, 1993): 821–33. http://dx.doi.org/10.1139/t93-073.

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The problem of varying species of heavy metals existing as individual species or in combination with each other in simulated contaminant leachates (solutions) is studied in relation to selectivity and retention in four different kinds of soil. The influence of pH on the retention characteristics is also examined. The results obtained from the heavy metals single-species and composite-species adsorption tests indicate that in evaluating the attenuation potential of the soil substrate (i.e., contaminant attenuation), account needs to be given to the sensitivity of the soil – heavy metals contaminant system to the pH of the leachate and the competitive effect between the heavy metals present in the leachate. A change in the soil solution pH results in a corresponding change of the dominant retention mechanism of heavy metals in the soils. At high pH values, precipitation mechanisms (e.g., precipitating as hydroxides and (or) as carbonates) dominate. As pH decreases, precipitation becomes less important, and cation exchange becomes dominant. High amounts of heavy metals are retained in the soils if the soil buffer capacity remains high enough to resist a change in pH. The selectivity order of heavy-metal retention in soils depends on the pH of soil solution. At soil solution pH values above 4 or 5, when precipitation prevails, the selectivity order obtained is given as Pb > Cu > Zn ≥ Cd, as demonstrated for the illite, montmorillonite, and natural clay soils. At lower soil solution pH values, the selectivity order obtained is given as Pb > Cd > Zn > Cu, as can be seen in the case of kaolinite and montmorillonite. Key words : heavy metals, retention, selectivity, preferential adsorption, precipitation.

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Albu, Raluca Marinica, Ecaterina Avram, Iuliana Stoica, and Silvia Ioan. "Polysulfones with chelating groups for heavy metals retention." Polymer Composites 33, no. 4 (March 2, 2012): 573–81. http://dx.doi.org/10.1002/pc.22174.

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Dubé, Jean-Sébastien, Rosa Galvez-Cloutier, and Thierry Winiarski. "Heavy metal transport in soil contaminated by residual light non-aqueous phase liquids (LNAPLs)." Canadian Geotechnical Journal 39, no. 2 (April 1, 2002): 279–92. http://dx.doi.org/10.1139/t01-113.

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This paper presents an experimental study on mixed soil contamination, more specifically on heavy metal behaviour in soil contaminated by residual non-aqueous phase liquids (NAPLs). Remediation of mixed contaminated sites is a complex technical goal because of the presence of physically and chemically different contaminants and potential interactions between them. Commonly encountered contaminants in mixed contaminated soils include light and dense organic liquids (LNAPLs, DNAPLs) and heavy metals. This study investigated interactions between three residual LNAPLs and three heavy metals (Cd, Cu, Pb) in a carbonated soil. The objectives of the study were to (i) establish the presence of interactive processes in the behaviour of the contaminants, with a focus on the influence of residual LNAPL on heavy metal transport and retention; and (ii) determine the nature of these interactions. Results showed that the LNAPL having the highest residual saturation enhanced heavy metal mobility and decreased heavy metal retention by the soil. On the other hand, the geochemical distribution of heavy metals was not significantly modified by chemical interactions with the residual LNAPLs. Specific modifications of Pb and Cu geochemical distributions rather appeared to be the result of modifications of soil hydrodynamics by residual LNAPL.Key words: contaminated soil, mixed contamination, heavy metals, LNAPL, preferential flow, contaminant mobility.

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Quinn, Ruth, and Alejandro Dussaillant. "The impact of macropores on heavy metal retention in sustainable drainage systems." Hydrology Research 49, no. 2 (February 19, 2018): 517–27. http://dx.doi.org/10.2166/nh.2018.277.

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Abstract Numerous laboratory and field experiments have found that rain gardens exhibit excellent heavy metal retention (>88%). However, none examined the impact of macropore flow on this retention; this was established to be a key factor in heavy metal capture by previous landfill leachate experiments. Therefore, the aim of the experiments detailed in this paper was to investigate the effect of a single artificial macropore on heavy metal retention in a layered soil column (with a similar configuration to a rain garden). The findings of these experiments suggest that macropore flow does not impact the hydraulic performance or heavy metal retention of the columns with 99% of copper, lead and zinc captured. This indicates that macropores are not detrimental to heavy metal retention in rain garden systems with highly conductive soils; this was attributed to the high hydraulic conductivity of the media used and the depth of the system. However, in shallower systems, such as green roofs, the retention of heavy metals and other pollutants may be impacted by the existence of preferential flow, and more research into this area is needed.

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Shanshan, Jia, and Zhou Yanqing. "Ecological Compensation Method for Soil Polluted by Heavy Metals Based on Internet of Things." Earth Sciences Research Journal 24, no. 2 (April 1, 2020): 153–61. http://dx.doi.org/10.15446/esrj.v24n2.87441.

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The traditional ecological compensation method for soil polluted by heavy metals is complicated and consumes a lot of manpower and material resources, and cannot meet the real life needs, so take the area where the soil is polluted by heavy metals as an example. Increasing soil retention in this area is the specific target for ecological compensation, and compensation for polluted areas is based on the internet of things. The willingness of users to participate in the land heavy metal pollution control project was studied, and the pollution degree was calculated. Through radio frequency identification information sensing equipment, the soil heavy metal pollution area was connected with the Internet according to the agreed agreement, and the information exchange was carried out, so as to provide the basis for the ecological compensation standard of soil heavy metal pollution area. According to the content, changing trend and characteristics of pollutants in the study area, the best forest species were selected for this area, and the soil retention was increased to the maximum extent in order to realize the ecological compensation to the area polluted by heavy metals. The final results show that the ecological compensation method for soil polluted with heavy metals based on the internet of things is cost-effective and has great feasibility, which can be the important means for sustainable development of ecological construction.

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9

Tam, N. F. Y., and Y. S. Wong. "Nutrient and Heavy Metal Retention in Mangrove Sediment Receiving Wastewater." Water Science and Technology 29, no. 4 (February 1, 1994): 193–200. http://dx.doi.org/10.2166/wst.1994.0189.

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Soil column studies were carried out to examine the capacity of mangrove sediments in retaining wastewater nutrients and heavy metals. Synthetic wastewater of three different concentrations, namely diluted sewage (DW), medium sewage (MW) and concentrated sewage (CW), were applied to the columns daily over a period of 54 days. Leachate from each column was collected and analyzed. The study revealed that the concentrations of ammonium in the leachates from all sewage treatments decreased dramatically in the first week with a pattern similar to the control. After this initial decrease, ammonium contents increased rapidly especially in the column treated with CW, then remained at a steady level. At the end of the experimental period, the concentrations of ammonium found in the leachate were in the declining order of CW > MW > DW > control. Organic nitrogen, nitrites and nitrates were not detected in the leachates from all sewage treatments. This suggested that denitrification might have occurred and some of the nitrogen from sewage might have been retained in the mangrove sediment. The changes in leachate K concentration were similar to that of NH4+-N content. On the other hand, the soluble phosphorus and heavy metal contents of leachates from sewage treated columns were similar to those of the control. Most of the heavy metals, including Cu, Zn and Cd, were not detected in the leachate. The sediment data showed that NH4+-N, ortho-P, and heavy metals were accumulated on the top layer of the soil column and their contents decreased with the depth of the soil column. The highest metal content was found in the column treated with concentrated sewage. It is clear that mangrove sediments acted as a good filter/trap for phosphorus and metals, but were less efficient for ammonium nitrogen.

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10

Søberg, Laila C., Jes Vollertsen, Godecke-Tobias Blecken, Asbjørn Haaning Nielsen, and Maria Viklander. "Bioaccumulation of heavy metals in two wet retention ponds." Urban Water Journal 13, no. 7 (March 30, 2015): 697–709. http://dx.doi.org/10.1080/1573062x.2015.1024689.

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11

Wasay, S. A., S. Barrington, and S. Tokunaga. "Retention Form of Heavy Metals in Three Polluted Soils." Soil and Sediment Contamination (formerly Journal of Soil Contamination) 7, no. 1 (January 1, 1998): 103–19. http://dx.doi.org/10.1080/10588339891334186.

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12

Ademola, Ajayi-Banji, Ogunlela Ayo, and Ogunwande Gbolabo. "Investigation of locust bean husk char adsorbability in heavy metal removal." Research in Agricultural Engineering 63, No. 1 (March 28, 2017): 29–35. http://dx.doi.org/10.17221/44/2015-rae.

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he column adsorption study examines irrigation water treatment prior to its application in order to ensure water-crop-consumer heavy metal transfer reduction to the safe level using locust bean husk char (LBHC) as biosorbent. Char structural pattern was investigated with SEM-EDX machine. Contaminated surface water was introduced simultaneously into the bioreactors containing 100 and 200 g of LBHC and collected after 30, 60, 90 120 and 150 min of detention time. Removal efficiency, isotherm and kinetic sorption model were the evaluation tools for the study. Percent of Cr, Cd and As removal at 150 min retention time were 83.33, 100 and 100%, respectively for 100 g biosorbents. A similar trend was observed for Cr and As removal at the same retention time for 200 g of LBHC. Metals sorption conforms to the Freundlich isotherm with correlation coefficient values greater than 0.92. Experimental kinetics had a good fit for pseudo second order (R<sup>2</sup> > 0.94 for most cases). Removal efficiency is a function of contact time, biosorbent dosage and metal concerned. Locust bean husk char has good and effective treatability for some heavy metals in mildly polluted water.

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Moghal, Arif Ali Baig, Mohammed Abdul Lateef, Syed Abu Sayeed Mohammed, Kehinde Lemboye, Bhaskar C. S. Chittoori, and Abdullah Almajed. "Efficacy of Enzymatically Induced Calcium Carbonate Precipitation in the Retention of Heavy Metal Ions." Sustainability 12, no. 17 (August 28, 2020): 7019. http://dx.doi.org/10.3390/su12177019.

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This study evaluated the efficacy of enzyme induced calcite precipitation (EICP) in restricting the mobility of heavy metals in soils. EICP is an environmentally friendly method that has wide ranging applications in the sustainable development of civil infrastructure. The study examined the desorption of three heavy metals from treated and untreated soils using ethylene diamine tetra-acetic acid (EDTA) and citric acid (C6H8O7) extractants under harsh conditions. Two natural soils spiked with cadmium (Cd), nickel (Ni), and lead (Pb) were studied in this research. The soils were treated with three types of enzyme solutions (ESs) to achieve EICP. A combination of urea of one molarity (M), 0.67 M calcium chloride, and urease enzyme (3 g/L) was mixed in deionized (DI) water to prepare enzyme solution 1 (ES1); non-fat milk powder (4 g/L) was added to ES1 to prepare enzyme solution 2 (ES2); and 0.37 M urea, 0.25 M calcium chloride, 0.85 g/L urease enzyme, and 4 g/L non-fat milk powder were mixed in DI water to prepare enzyme solution 3 (ES3). Ni, Cd, and Pb were added with load ratios of 50 and 100 mg/kg to both untreated and treated soils to study the effect of EICP on desorption rates of the heavy metals from soil. Desorption studies were performed after a curing period of 40 days. The curing period started after the soil samples were spiked with heavy metals. Soils treated with ESs were spiked with heavy metals after a curing period of 21 days and then further cured for 40 days. The amount of CaCO3 precipitated in the soil by the ESs was quantified using a gravimetric acid digestion test, which related the desorption of heavy metals to the amount of precipitated CaCO3. The order of desorption was as follows: Cd > Ni > Pb. It was observed that the average maximum removal efficiency of the untreated soil samples (irrespective of the load ratio and contaminants) was approximately 48% when extracted by EDTA and 46% when extracted by citric acid. The soil samples treated with ES2 exhibited average maximum removal efficiencies of 19% and 10% when extracted by EDTA and citric acid, respectively. It was observed that ES2 precipitated a maximum amount of calcium carbonate (CaCO3) when compared to ES1 and ES3 and retained the maximum amount of heavy metals in the soil by forming a CaCO3 shield on the heavy metals, thus decreasing their mobility. An approximate improvement of 30% in the retention of heavy metal ions was observed in soils treated with ESs when compared to untreated soil samples. Therefore, the study suggests that ESs can be an effective alternative in the remediation of soils contaminated with heavy metal ions.

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Melcer, H., H. Monteith, and S. G. Nutt. "Activated Sludge Process Response to Variable Inputs of Heavy Metals." Water Science and Technology 25, no. 11 (June 1, 1992): 387–94. http://dx.doi.org/10.2166/wst.1992.0317.

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Laboratory-scale activated sludge treatment systems were operated under dynamic loading conditions to investigate the non-steady state behaviour of heavy metal contaminants under controlled conditions. Four step tests were conducted in which an incremental increase in the concentrations of selected contaminants was applied to the reactor feed from background levels of about 100 µg/L to levels of about 1000 µg/L for each metal over a period of approximately three hydraulic retention times. Effluent metal concentrations rose significantly to levels of approximately 500 µg/L. They remained elevated for long periods after termination of the metal perturbations. Solids retention time (SRI) did not appear to influence metal removal efficiency over the range tested. Hydraulic retention time (HRT) effects were difficult to discern from the confounding effect of influent metal concentration.

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Hatt, B. E., A. Steinel, A. Deletic, and T. D. Fletcher. "Retention of heavy metals by stormwater filtration systems: breakthrough analysis." Water Science and Technology 64, no. 9 (November 1, 2011): 1913–19. http://dx.doi.org/10.2166/wst.2011.188.

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Biofiltration systems are widely used to mitigate the impacts of stormwater on receiving waters, however their long-term capacity to retain heavy metals has not previously been assessed. Accelerated-dosing laboratory experiments were used to assess the likelihood of breakthrough occurring for three different types of soil-based filter media that are commonly used in stormwater biofilters. In all cases, breakthrough of zinc (Zn) was observed, but not of cadmium (Cd), copper (Cu) and lead (Pb). If biofiltration systems are sized so that they are large relative to their catchment (at least 2–3% of its area) or have a deep filter layer (at least 0.5 m deep), then breakthrough will not occur for at least ten years and probably longer. However, after the equivalent of 12–15 years of operation, Cd, Cu and Zn had accumulated in the filter media to levels that exceeded human health and/or ecological guidelines. Further, depending on the design, it is possible that spent filter media may be classified as contaminated soil and thus require special disposal.

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Chougui, A., K. Zaiter, A. Belouatek, and B. Asli. "Heavy metals and color retention by a synthesized inorganic membrane." Arabian Journal of Chemistry 7, no. 5 (November 2014): 817–22. http://dx.doi.org/10.1016/j.arabjc.2012.11.017.

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17

Tyler, Germund. "Uptake, retention and toxicity of heavy metals in L ichens." Water, Air, and Soil Pollution 47, no. 3-4 (October 1989): 321–33. http://dx.doi.org/10.1007/bf00279330.

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Urase, T., M. Salequzzaman, S. Kobayashi, T. Matsuo, K. Yamamoto, and N. Suzuki. "Effect of high concentration of organic and inorganic matters in landfill leachate on the treatment of heavy metals in very low concentration level." Water Science and Technology 36, no. 12 (December 1, 1997): 349–56. http://dx.doi.org/10.2166/wst.1997.0464.

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Various heavy metals in the landfill leachates were measured up to very low concentration levels of micrograms per litre. Though no violation to Japanese effluent standards was found in respect of individual metal, leachate or treated leachate it still contains higher concentrations of total heavy metals than surrounding water environment. The effluent concentration after treatment was of the same order as raw leachate. Maximum metal solubilities in leachate were calculated taking the presence of inorganic metal complexes into account. Solubilities of metals were high enough and they were not the limiting factor determining concentrations after coagulation. The coagulation with higher pH was not successful in reducing concentration of leachate - origin - metals contrary to the case of pure chemical metals. The heavy metals especially nickel and copper in the leachate were associated with organic matter and consequently they remained in solution unless organic matter was removed. Application of nanofiltration to leachate treatment was studied. It was possible to separate metals from less toxic salts by low retention nanofiltration membranes.

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Rubin Pedrazzo, Smarra, Caldera, Musso, Dhakar, Cecone, Hamedi, Corsi, and Trotta. "Eco-Friendly β-cyclodextrin and Linecaps Polymers for the Removal of Heavy Metals." Polymers 11, no. 10 (October 11, 2019): 1658. http://dx.doi.org/10.3390/polym11101658.

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Environment-friendly nanosponges, having a high content of carboxyl groups, were synthesized by crosslinking β-cyclodextrin and linecaps, a highly soluble pea starch derivative, with citric acid in water. Additionally, pyromellitic nanosponges were prepared by reacting β-cyclodextrin and linecaps with pyromellitic dianhydride in dimethyl sulfoxide and used in comparison with the citric nanosponges. After ion-exchange of the carboxyl groups H+ with sodium ions, the ability of the nanosponges to sequester heavy metal cations was investigated. At a metal concentration of 500 ppm, the pyromellitate nanosponges exhibited a higher retention capacity than the citrate nanosponges. At lower metal concentrations (≤50 ppm) both the citrate and the pyromellitate nanosponges showed high retention capacities (up to 94% of the total amount of metal), while, in the presence of interfering sea water salts, the citrate nanosponges were able to selectively adsorb a significantly higher amount of heavy metals than the pyromellitate nanosponges, almost double in the case of Cu2+.

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Wojciechowska, Ewa, and Magdalena Gajewska. "Partitioning of heavy metals in sub-surface flow treatment wetlands receiving high-strength wastewater." Water Science and Technology 68, no. 2 (July 1, 2013): 486–93. http://dx.doi.org/10.2166/wst.2013.283.

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The retention of heavy metals at two pilot-scale treatment wetlands (TWs), consisting of two vertical flow beds (VSSF) followed by a horizontal flow bed (HSSF) was studied. The TWs received high-strength wastewater: reject waters from sewage sludge centrifugation (RW) and landfill leachate (LL). The concentrations of the metals Fe, Mn, Zn, Al, Pb, Cu, Cd, Co, and Ni were measured in treated wastewater, substrate of the beds and in plant material harvested from the beds (separately in above ground (ABG) parts and below ground (BG) parts). The TWs differed in metals retention. In the RW treating TW the metal removal efficiencies varied from 27% for Pb to over 97% for Fe and Al. In the LL treating system the concentrations of most metals decreased after VSSF-1 and VSSF-2 beds; however, in the outflow from the last (HSSF) bed, the concentrations of metals (apart from Al) increased again, probably due to the anaerobic conditions at the bed. A major removal pathway was sedimentation and adsorption onto soil substrate as well as precipitation and co-precipitation. In the LL treating facility the plants contained substantially higher metal concentrations in BG parts, while the upward movement of metals was restricted. In the RW treating facility the BG/ABG ratios were lower, indicating that metals were transported to shoots.

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Butsiak, G. A., O. V. Shved, Z. V. Hubriі, and V. I. Butsiak. "Features of ecosorption by enterosorbent under toxic loading of heavy metals." Chemistry, Technology and Application of Substances 3, no. 2 (November 1, 2020): 85–92. http://dx.doi.org/10.23939/ctas2020.02.085.

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The possibilities of using enterosorbents as mineral additives for bioprophylaxis and prevention of heavy metal retention in the body due to possible food contamination as a result of ecosystem biobalance and their accumulation in livestock bioproducts are analyzed. The dynamics of changes in physiological parameters of the body of experimental animals under the influence of heavy metals depending on the used enterosorbents as effective preventive measures that can reduce the level of lead in the blood and liver of animals in intoxication to control levels.

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Tam, N. F. Y., and Y. S. Wong. "Retention and distribution of heavy metals in mangrove soils receiving wastewater." Environmental Pollution 94, no. 3 (1996): 283–91. http://dx.doi.org/10.1016/s0269-7491(96)00115-7.

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Reboreda, Rosa, and Isabel Caçador. "Halophyte vegetation influences in salt marsh retention capacity for heavy metals." Environmental Pollution 146, no. 1 (March 2007): 147–54. http://dx.doi.org/10.1016/j.envpol.2006.05.035.

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Kordialik-Bogacka, Edyta. "Surface properties of yeast cells during heavy metal biosorption." Open Chemistry 9, no. 2 (April 1, 2011): 348–51. http://dx.doi.org/10.2478/s11532-011-0008-8.

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AbstractProperties of metal solution, environmental conditions and the type of biomaterials (microorganism genus, species or even strain) influence the mechanism of metal biosorption and consequently metal adsorption capacity, affinity and specificity. Cell surface properties determine the metal-microorganism interactions to a large extent. In this work the relationship between yeast surface properties and yeast’s ability to bind cadmium, lead and copper was studied. Surface charge and hydrophobicity before and after biosorption were determined using dye retention and solvent partition assays, respectively. There were differences in the surface charge and relative hydrophobicity among different yeast strains. A higher metal adsorption capacity for more negatively charged yeast cells was observed. Biosorption of heavy metals resulted in modifications to the surface charge and hydrophobicity of yeast cells. However, there were not statistically significant changes in the yeast surface charge and hydrophobicity after binding of heavy metals depending on the nature of the metal, initial metal concentration and solution pH.

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Hossain, M. A., H. Furumai, F. Nakajima, and R. K. Aryal. "Heavy metals speciation in soakaways sediment and evaluation of metal retention properties of surrounding soil." Water Science and Technology 56, no. 11 (December 1, 2007): 81–89. http://dx.doi.org/10.2166/wst.2007.746.

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Heavy metals speciation analysis was carried out on sediment samples accumulated within soakaways in an old stormwater infiltration facility in Tokyo, Japan and on a soil core sample collected near the facility. Heavy metals content in soakaways sediments were much elevated compared to nearby surface soil with the content for Zn, Pb and Cd reaching about 5 to 10 times the content in surface soil. Speciation results revealed that significant amount of the accumulated heavy metals were present in potential mobile fractions, posing threat of release to underlying soil with changing environmental conditions. Detail analyses of soil characteristics indicated significant heterogeneity with depth, especially between the surface soil and underlying soil at site. Decrease in potential adsorption sites with depth was observed in case of underlying soil. Reduced adsorption capacity for heavy metals was evidenced for underlying soil when compared with surface soil. Furthermore, less capability of the soil organic matter to bind heavy metals was evidenced through speciation analyses, which raises concern over the long-term pollution retention potential of the underlying soil receiving infiltrated runoff.

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Dhiman, Jaskaran, Shiv O. Prasher, Eman ElSayed, Ramanbhai Patel, Christopher Nzediegwu, and Ali Mawof. "Use of Polyacrylamide Superabsorbent Polymers and Plantain Peel Biochar to Reduce Heavy Metal Mobility and Uptake by Wastewater-Irrigated Potato Plants." Transactions of the ASABE 63, no. 1 (2020): 11–28. http://dx.doi.org/10.13031/trans.13195.

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HighlightsAmending soil with SAP+BC and SAP reduced Cd, Cu, and Zn uptake into potato tubers.SAP+BC treatment led to greater Cd and Zn retention in topsoil.Acrylamide monomers were not detected in potatoes grown in SAP-amended soil.Potato peels accumulated higher concentrations of heavy metals than tuber flesh.Abstract. Agriculture is the largest consumer of freshwater; therefore, use of alternate sources for irrigation, such as wastewater, could alleviate increasing stress on freshwater resources. However, wastewater may contain contaminants such as heavy metals (Cd, Cr, Cu, Fe, Pb, and Zn), which could be taken up by food crops and/or contaminate groundwater. To reduce the mobility of heavy metals in soil and deter their uptake by potatoes ( L.) irrigated with synthetic wastewater, polyacrylamide superabsorbent polymer (SAP) and a mixture of SAP and plantain peel biochar (SAP+BC) were tested as soil amendments. The experiment was performed in field lysimeters packed with sandy soil. SAP was incorporated into the soil layer from 0.15 to 0.25 m below the surface and BC was mixed into the top 0.10 m of soil, both at an application rate of 1% (w/w). Leachate and composite soil samples from different depths, collected after each irrigation event, were analyzed for heavy metals. Upon harvest, different plant parts were subjected to heavy metal analysis. Compared to the untreated control, the SAP+BC treatment led to significantly greater (p < 0.05) retention of Cd and Zn in the topsoil while significantly reducing (p < 0.05) Cd, Cu, and Zn uptake into potato tuber flesh tissue and Cd uptake into tuber peels. The SAP treatment also significantly reduced (p < 0.05) Cd uptake in the tuber as compared to the control. Acrylamide monomers were not detected in tuber flesh and peel samples for all treatments, indicating possible safe use of SAP and BC in soils to reduce heavy metal leaching and uptake by plants. Keywords: Biochar, Heavy metals, Hydrogels, Lysimeter, Plant uptake, Superabsorbent polymers, Wastewater.

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Obarska-Pempkowiak, H. "Retention of selected heavy metals: Cd, Cu, Pb in a hybrid wetland system." Water Science and Technology 44, no. 11-12 (December 1, 2001): 463–68. http://dx.doi.org/10.2166/wst.2001.0867.

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The budget of heavy metals was investigated in a constructed wetland in a hybrid wetland system near Gdan«sk. It is a pilot wastewater treatment plant (WWTP) designed for 150 PE (person equivalent). The system consists of two sections: a vegetated submerged bed (VSB) with horizontal flow of sewage and a cascade filter situated on a slope of a hill. Total area of the constructed wetland is about 870 m2. Domestic sewage, after a conventional pretreatment (consisting of an Imhoff tank and a trickling filter) is pumped to the VSB filter located on the top of the hill and then flows through subsequent segments of the constructed wetland. In the period 1995-98 the measurements of several heavy metals (Cd, Cu, Pb) were carried out in sewage inflowing, outflowing and collected from the in between sections of the system. Moreover analysis of sediment collected in ditches of the cascade filter, VSB filter and reed were carried out. The content of heavy metals in suspended solids decreased along the course of treatment, starting from VSB filter, through the first ditch to the last ditch. Measurable concentrations of dissolved heavy metals were found in sewage collected from several subsequent ditches. Sorption was deemed the main mechanism of dissolved metals removal in subsequent ditches.

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Wen, Yuan, Ivan J. Vechetti, Alexander P. Alimov, Jessica F. Hoffman, Vernieda B. Vergara, John F. Kalinich, John J. McCarthy, and Charlotte A. Peterson. "Time-course analysis of the effect of embedded metal on skeletal muscle gene expression." Physiological Genomics 52, no. 12 (December 1, 2020): 575–87. http://dx.doi.org/10.1152/physiolgenomics.00096.2020.

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As a consequence of military operations, many veterans suffer from penetrating wounds and long-term retention of military-grade heavy metal fragments. Fragments vary in size and location, and complete surgical removal may not be feasible or beneficial in all cases. Increasing evidence suggests retention of heavy metal fragments may have serious biological implications, including increased risks for malignant transformation. Previous studies assessed the tumorigenic effects of metal alloys in rats, demonstrating combinations of metals are sufficient to induce tumor formation after prolonged retention in skeletal muscle tissue. In this study, we analyzed transcriptional changes in skeletal muscle tissue in response to eight different military-relevant pure metals over 12 mo. We found that most transcriptional changes occur at 1 and 3 mo after metal pellets are embedded in skeletal muscle and these effects resolve at 6 and 12 mo. We also report significant immunogenic effects of nickel and cobalt and suppressive effects of lead and depleted uranium on gene expression. Overall, skeletal muscle exhibits a remarkable capacity to adapt to and recover from internalized metal fragments; however, the cellular response to chronic exposure may be restricted to the metal-tissue interface. These data suggest that unless affected regions are specifically captured by biopsy, it would be difficult to reliably detect changes in muscle gene expression that would be indicative of long-term adverse health outcomes.

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Ida, Sylwan, and Thorin Eva. "Removal of Heavy Metals during Primary Treatment of Municipal Wastewater and Possibilities of Enhanced Removal: A Review." Water 13, no. 8 (April 19, 2021): 1121. http://dx.doi.org/10.3390/w13081121.

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Resource reuse has become an important aspect of wastewater management. At present, use of sludge in agriculture is one of the major reuse routes. Conventional municipal wastewater treatment does not involve any designated process for removal of heavy metals, and these distribute mainly between effluent and sludge. Enhanced removal of heavy metals during primary treatment may decrease the heavy metal concentrations in both effluent and sludge from secondary treatment and promote long-term reuse of secondary sludge. This review considers heavy metal occurrence and removal during primary settling, together with possible treatment technologies for heavy metal removal in primary settlers and their theoretical performance. The variation in total heavy metal concentrations and dissolved fraction in raw municipal wastewater points to a need for site-specific assessments of appropriate technologies for improved heavy metal removal. Studies examining the heavy metal speciation beyond dissolved/particulate are few. Missing or disparate information on process parameters such as hydraulic retention time, pH and composition of return flows makes it hard to generalize the findings from studies concerning heavy metal removal in primary settlers. Coagulation/flocculation and use of low-cost sorbents were identified as the most promising methods for enhancing heavy metal removal during primary settling. Based on the available data on heavy metal speciation and removal during primary settling, sorption technologies may be most effective for enhancing the removal of Cu and Ni, while coagulation may be efficient for Cd, Cr, Cu, Pb, Zn and Hg removal (but not as efficient for Ni removal).

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Deptuła, A., J. Chwastowska, Wiesława Łada, T. Olczak, D. Wawszczak, E. Sterlinska, B. Sartowska, and K. C. Goretta. "Sol-Gel-Derived Hydroxyapatite and its Application to Sorption of Heavy Metals." Advances in Science and Technology 45 (October 2006): 2198–203. http://dx.doi.org/10.4028/www.scientific.net/ast.45.2198.

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Hydroxyapatite (HA) microspheres of diameter <70 μm have been synthesized by solgel processing. The starting sols were prepared by ultrasonic mixing of concentrated solutions of calcium acetate (1.7M) with 85% H3PO4, followed by emulsification in dehydrated 2-ethyl-1- hexanol. Drops of emulsion were solidified by extraction of water with this solvent. The final thermal treatment was a 2 h soaking in air at 900°C. Properties such as hydraulic resistance and sedimentation rate, which are important for application in ion-exchangers, were superior for our prepared microspheres in comparison with irregularly shaped commercial HA. Adsorption of the following metals was investigated: U, Zn, Fe, Cu, Ni, Co, Cd, Pb, Mn, Al, Cr, As, Sb, Bi and Mo. Retention was ≈100% for of all the metals studied when pH > 3–4. On average, ≈1/20 moles of metal reacted with 1 mole of HA. Adsorbed metals could be desorbed with efficiencies of 60–90%. In addition, nuclear-waste-saturated beds of HA could be transformed to insoluble ceramics by thermal treatment. The cost of producing HA microspheres was estimated to be comparable to current prices of irregularly shaped commercial hydroxyapatite powders. For radioactive contaminants such as U, for which resorption need not be considered, porous monoliths were produced by use of industrial reagents. The retention capacity was determined to be 30 mg of U per 1 mg of monolith.

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Irshad, Muhammad, Rahat Ullah Khan, Saima Jadoon, Amjad Hassan, and A. Egrinya Eneji. "Effect of phosphate rock on the solubility of heavy metals in soils saturated with industrial wastewater." Canadian Journal of Soil Science 94, no. 4 (August 2014): 543–49. http://dx.doi.org/10.4141/cjss2013-063.

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Irshad, M., Khan, R. U., Jadoon, S., Hassan, A. and Egrinya Eneji, A. 2014. Effect of phosphate rock on the solubility of heavy metals in soils saturated with industrial wastewater. Can. J. Soil Sci. 94: 543–549. An in situ technology for immobilizing metals in polluted soils could be a more effective approach to managing their toxicity to the environment, especially plants. The aim of this study was to investigate the effect of milled phosphate rock (PR) on the sorption of Ni, Cd and Cu ions in differently textured soils polluted with industrial wastewater. For this purpose, soils were mixed with two particle size fractions (0.2 mm and 1 mm) of PR material. Each material was applied at the rate of 0, 2.5 and 5%. Results showed that PR amendment reduced the solubilization of heavy metals in the order sandy clay loam>sandy loam>loamy sand. Metal concentrations in soils saturated with industrial wastewater were in the order Ni>Cd>Cu. Solubilization of metal ions in soils also reduced with the increase in the amount of rock phosphate added. This occurred more with the finer PR fraction. The concentrations of heavy metals in soils varied directly with their respective concentrations in the wastewater. Saturating soil with wastewater for a longer time increased the solubility of heavy metals. The adsorptive capacity of heavy metals from the respective aqueous solution also increased with increasing shaking time. The finer PR particles better enhanced the sorption capacity of heavy metals. This study indicated that the retention of heavy metals by PR mineral in contaminated soils may reduce the contamination risk in surface and subsurface waters.

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Salánki, J., I. Licskó, F. László, K. V.-Balogh, I. Varanka, and Z. Mastala. "Changes in the Concentration of Heavy Metals in the Zala Minor Balaton-Zala System (Water, Sediment, Aquatic Life)." Water Science and Technology 25, no. 11 (June 1, 1992): 173–80. http://dx.doi.org/10.2166/wst.1992.0289.

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The changes in the concentration of seven heavy metals (Hg, Cd, Pb, Cr, Ni, Cu, Zn) in the water, sediment and aquatic organisms were studied in the River Zala, the largest tributary to Lake Balaton, and in the retention pond (Balaton Minor) created on the tributary. The samples have been collected at four stations, in ice-free periods, at monthly intervals for four years. In the water the mean concentrations of the heavy metals studies are one order of magnitude below the levels mentioned as allowable limits in the WHO recommendations on drinking water. In the sediment the concentration measured for the heavy metals remain below the limit acceptable for plants in soils (except for lead in the samples retrieved from the mouth of the River Zala). The concentration of solid lead and chromium compounds has surpassed in all samples that of the dissolved ones. The concentration of lead and chromium, but also that of nickel and zinc decrease thus perceptibly from the upper reaches of the River Zala towards the outflow from Minor Balaton. The analyses on fish and snails demonstrated the retention of Cu and occasionally of Pb and Hg in the pond, but also that the metal pollution reaching the pond is subject to seasonal and yearly fluctuations.

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Rencová, J., A. Vlková, and G. Veselá. "727 Influence of heavy metals upon retention of polonium-210 in rat." Toxicology Letters 144 (September 2003): s195. http://dx.doi.org/10.1016/s0378-4274(03)90726-0.

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Tijani, Najib, Khalid Yamni, Said Lamsiah, and AbdelhadiEl Krouk. "Synthesis of type A Zeolite membrane: Application for retention of heavy metals." IOSR Journal of Environmental Science, Toxicology and Food Technology 8, no. 5 (2014): 90–93. http://dx.doi.org/10.9790/2402-08549093.

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Belaicha, Nacira, Wahiba Lemlikchi, Med Oimar Mecherri, Patrick Sharrock, and Ange Nzihou. "Composite Material with Calcium Sulfate and Calcium Phosphate for Heavy Metals Retention." Procedia Engineering 83 (2014): 403–6. http://dx.doi.org/10.1016/j.proeng.2014.09.048.

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Rivas, B. L., H. A. Maturana, I. M. Perich, and U. Angne. "Polyethyleneimine supports for resins with retention properties for heavy metals part I." Polymer Bulletin 14, no. 3-4 (October 1985): 239–43. http://dx.doi.org/10.1007/bf00254944.

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Lassabatère, L., T. Winiarski, and R. Galvez-Cloutier. "Can geotextiles modify the transfer of heavy metals transported by stormwater in infiltration basins?" Water Science and Technology 51, no. 2 (January 1, 2005): 29–36. http://dx.doi.org/10.2166/wst.2005.0029.

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Geotextiles are fibrous materials increasingly employed for the design of infiltration basins. However, their influence on the transfer of contaminants carried by stormwater has not been fully investigated. This study, based on column leaching experiments, aims at showing the effect of geotextiles on the transfer of three heavy metals (Zn, Pb and Cd) in a reactive soil (simulating an infiltration basin at laboratory scale). This effect depends on several factors, such as type of geotextile, hydric conditions (geotextile water content), hydraulic conditions (flow-rates) and the number of geotextiles installed. In all cases, geotextiles influence heavy metal retention by modifying flow and thus regulating contact between these metals and the reactive soil.

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Li, Yang, Shao Hong You, Xu Jin, and Zi Yu Lin. "The Analysis of Adsorptive Ability of Pb, Cd by Acorus calamus." Applied Mechanics and Materials 522-524 (February 2014): 619–22. http://dx.doi.org/10.4028/www.scientific.net/amm.522-524.619.

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The article analyzed the adsorptive ability of acorus calamus to Pb,Cd in soil through pot experiment. The results show that with the increase of concentration of this two kinds of heavy metals,the growth of acorus calamus have been obviously affected.The concentration of two kinds of heavy metals in the acorus calamus root is far more than in the cauline leaf,which show that acorus calamus have very strong retention effect on these five kinds of heavy metals. As acorus calamus absorb the Pb much more than Cd can be seen through the experiment.

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39

Aldesuquy, Heshmat Soliman. "Polyamines in relation to metal concentration, distribution, relative water content and abscisic acid in wheat plants irrigated with waste water heavily polluted with heavy metals." International Journal of Bioassays 5, no. 05 (May 3, 2016): 4534. http://dx.doi.org/10.21746/ijbio.2016.05.002.

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Present study was carried out in order to investigate the effect of grain presoaking in spermine (0.15 mM), spermidine (0.3 mM) and their interaction on growth vigor, metal distribution as well as leaf turgidity and abscisic acid in wheat plants. Waste water at concentrations 25%, 50% and 100% caused noticeable decreases in growth vigor of root and shoot, leaf area, relative water content and water use efficiency. On the other hand, waste water stress caused remarkable increases in heavy metals and saturation water deficit as well as abscisic acid content of flag leaf. Exogenous application of Spm, Spd or their interaction could counteract the adverse effects of heavy metals in waste water by improving growth vigor of root and shoot, water use efficiency, retention of leaf turgidity and decreasing abscisic acid in leaves and grains. Furthermore, these polyamines reduced heavy metals translocation from root to leaves till reach to grains.

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de Mello-Castanho, Sonia Regina Homem, Antônio Carlos da Silva, Wilson Acchar, and Ana M. Segadães. "Corrosion Behaviour of Vitrified Heavy Metals from Industrial Waste." Advances in Science and Technology 45 (October 2006): 178–83. http://dx.doi.org/10.4028/www.scientific.net/ast.45.178.

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The vitrification process is an attractive route for the inertization treatment of hazardous industrial wastes. The corrosion resistance of this kind of materials is one of the most important requirements to ensure the long term retention of the toxic metals. In this work, silicate glasses with various waste concentrations were obtained using a galvanic sludge from metallurgical activities and glass forming rejects from ceramic activities. Glasses with several galvanic waste concentrations were obtained. The corrosion behaviour of the vitrified materials under various pH media was evaluated. The FTIR technique was used to investigate the glass structural modifications. Glasses containing 40 wt.% galvanic waste additions show higher resistance to corrosion media than those without waste additions.

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Zheng, Yang, and Jianmin Zhang. "Experimental study on the adsorption of dissolved heavy metals by nano-hydroxyapatite." Water Science and Technology 82, no. 9 (September 23, 2020): 1825–32. http://dx.doi.org/10.2166/wst.2020.465.

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Abstract Bioretention system is an effective way to solve the problem of urban water environment pollution. In this paper, the difficulty of the existing biological retention system to effectively remove dissolved heavy metals was studied. By comparing the adsorption effect of acid quartz sand filler layers with nano-hydroxyapatite (N-HAP), medical stone, nano-carbon, and biochar, the conclusion is drawn from the static and cylinder dynamic experiments that N-HAP has the best effect of removing Cu2+ and Zn2+, and the effect is long lasting. The scanning electron microscopy results showed that the N-HAP particles were rough and the surface was more rod-shaped, which increased the specific surface area of the N-HAP particles, promoted the complexation and electrostatic interaction of the additives and heavy metal solutions, and facilitated the adsorption of heavy metals. The research results help to improve the technology of filler matrix modification.

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Halecki, Wiktor, Tomasz Kowalik, and Andrzej Bogdał. "Multiannual Assessment of the Risk of Surface Water Erosion and Metal Accumulation Indices in the Flysch Stream Using the MARS Model in the Polish Outer Western Carpathians." Sustainability 11, no. 24 (December 15, 2019): 7189. http://dx.doi.org/10.3390/su11247189.

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The anthropogenic problems in richly sculpted areas (mountain and submontane) are mainly related to agricultural activity, which shapes the quality of surface waters. This paper presents an analysis of the results of the hydrochemical tests carried out in the years 2007–2018 at check-control spots. The heavy metal pollution index (HPI < 100) indicated a low risk for aquatic organisms. The statistical calculations obtained by means of multivariate adaptive regression splines (MARS) designated that the hazard quotient (HQ) index can be combined with the electrical conductivity (EC) and total dissolved substances (TDS) parameters used in the assessment of water erosion. The HQ index showed that the concentration of individual heavy metals is lower than their value in the 0.5 percentile of the value. In subsequent studies, it should be assessed whether the size of arable land has an impact on the increased concentration of heavy metals in the surface water. We recommend small retention reservoirs as a potential management measure to improve the quality of the surface water at a regional scale. This study has great potential to mitigate the degradation processes related to the insufficient storage capacity, and to promote natural water retention.

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Tyagi, R. D., D. Couillard, and F. T. Tran. "Studies on Microbial Leaching of Heavy Metals from Municipal Sludge." Water Science and Technology 22, no. 12 (December 1, 1990): 229–38. http://dx.doi.org/10.2166/wst.1990.0117.

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A comparative study between continuous stirred tank reactor (CSTR) with cell recycle and air-lift reactor was carried out in 30 1 capacity reactors for metal solubilization from anaerobically digested sludge. In CSTR at a residence time of 0.75 day, supplementing the feed sludge with 4 g/l of FeSO4.7H2O, using 20% sludge recycle and adjusting pH of the feed sludge to 4.5 resulted in following metal solubilization : 91% Cu, 94% Zn,, 93% Mn, 67% Cd, 67% Ni, 8% Cr, and 7% Pb. At 0.75 day retention time metals were solubilized to the recommended level in CSTR as well as in air-lift reactor. The treated sludge is easy to filter in plates filter press, centrifugation, or vacuum filter. The sludge nutrients do not seem to be diminished as a result of treatment and separation of solid-liquid. The ammonia-nitrogen fraction seems to be transformed in organic nitrogen. The decontaminated sludge produced has less odour.

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Durin, B., B. Béchet, M. Legret, and P. Le Cloirec. "Role of colloids in heavy metal transfer through a retention-infiltration basin." Water Science and Technology 56, no. 11 (December 1, 2007): 91–99. http://dx.doi.org/10.2166/wst.2007.762.

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Runoff waters from a main bridge near Nantes (France), surface waters and pore waters in the infiltration basin collecting runoff were analysed after filtration and ultrafiltration to investigate the role of colloids in the transfer of trace metals (Zn, Cu and Pb) from the road to the groundwater. The role of the basin in mitigation of the variations of physico-chemical parameters and chemical elements concentrations was confirmed. An increase of mobile colloidal phase by comparison with runoff and high concentrations of trace metals were observed in pore waters of the sediment. Up to 100% of Pb and 60% of Cu and Zn may be associated to compounds having a molecular weight above 5 kDaltons. Principal component analysis outlined the variability of the influence of the physico-chemical parameters on trace metals concentrations for the different waters. Speciation calculations pointed out the potential precipitation of Fe and Al oxyhydroxides in all kind of waters.

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Corral-Bobadilla, Marina, Ana González-Marcos, Eliseo Vergara-González, and Fernando Alba-Elías. "Bioremediation of Waste Water to Remove Heavy Metals Using the Spent Mushroom Substrate of Agaricus bisporus." Water 11, no. 3 (March 4, 2019): 454. http://dx.doi.org/10.3390/w11030454.

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The presence of heavy metals in waste water brings serious environmental pollution that threatens human health and the ecosystem. Bioremediation of heavy metals has received considerable and growing interest over the years. Thus, this paper presents the use of the Spent Mushroom Substrate (SMS) of Agaricus bisporus cultivation as a bioremediating agent to remove heavy metals that are present in industrial waters. These metals include chromium, lead, iron, cobalt, nickel, manganese, zinc, copper and aluminium. In particular, this study analyses the performance of SMS bioreactors with different groups of heavy metals at various concentrations. Between 80% and 98% of all contaminants that were analysed can be removed with 5 kg of SMS at hydraulic retention times of 10 and 100 days. The best removal efficiencies and longevities were achieved when removing iron (III), nickel and cobalt from contaminated water at a pH of 2.5. These results suggest that SMS can successfully treat waste water that has been contaminated with heavy metals.

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Naveed, Ahmad, Najaf Ali, Muhammad Ashraf, and Hafiz Miqdad Masood. "Removal of Heavy Metals from Wastewater of Textile Industry Using Polymeric Nano-Adsorbent." NFC IEFR Journal of Engineering and Scientific Research 7, no. 1 (December 1, 2019): 10–18. http://dx.doi.org/10.24081/nijesr.2019.1.0003.

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Wastewater of textile industry having impurities and heavy metal ions cause problems in human society that can endanger the human health through food chain. Adsorption of heavy metal ions before draining makes wastewater safe for aquatic life and human health. Now a day’s adsorption of heavy metal through polymeric nano adsorbents is the emerging technology which is more efficient than conventional adsorbents like activated carbon. The pH 9.0 gave maximum 96% sorption of Co at 1.0 g/L adsorbent dosage, due to increased electrostatic force of attraction produced by the negative charge at the surface of sorbent which is favorable for adsorbing cationic species. In the beginning of15 minute retention time, metal ions adsorption was rapid due to availability of more number of adsorptive sites but further increase of retention time decreased the sorption capacity due to partial desorption that may occur due to the charge density and diameter of hydrated ions. Similarly in case of Cu, the maximum sorption was 95% at 7.0 pH using 1.0 g/L adsorbent dosage.

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Campillo-Cora, Claudia, Manuel Conde-Cid, Manuel Arias-Estévez, David Fernández-Calviño, and Flora Alonso-Vega. "Specific Adsorption of Heavy Metals in Soils: Individual and Competitive Experiments." Agronomy 10, no. 8 (August 1, 2020): 1113. http://dx.doi.org/10.3390/agronomy10081113.

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The partitioning between the soil solid phase and the soil solution determines the mobility of pollutants like heavy metals. If nonspecific sorption takes place, the reactions are easily reversible and heavy metals are released to soil solution increasing the probability of leaching through soil profile. Mobility and leaching are also favoured if other metals are in the system and competition for specific adsorption sites takes place. In this study, desorption equilibrium experiments were conducted after adsorption ones. The specific adsorption was evaluated through the amounts of the still adsorbed Cu, Pb, Cr, Ni and Zn after desorption experiments in ten different soils. In addition, competition adsorption and desorption binary experiments were conducted for evaluating the metal competition in three of the soils. Pb and Cu are the metals adsorbed and retained in higher amounts in all the studied soils. In slightly neutral soils, Cr is retained in lesser amounts while in acidic soils Zn is the metal less retained. Results showed that despite the high and variable amounts of organic matter in the soils, soil pH is the most important variable in neutral soils. In acidic soils, soil properties different than pH play important roles and specific sorption of Pb is related to the cationic exchange capacity of the soils while that of Zn to the clay content. Instead, the release of Cu during desorption experiments is probably due to the more soluble organic fraction of the soils. The individual retention of Cu, Zn, Ni and Pb is higher than when they are in competition, except if Cr is present. In this case, the amount of those four metals and that of Cr increased. Therefore, the presence of Cr together with cationic heavy metals favoured the adsorption of those metals in multi-metal polluted areas. Specific adsorption is also important during competition as soil affinities increase during competition experiments.

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Azcue, J. M., W. C. Pfeiffer, M. Fiszman, and O. Malm. "Heavy Metals in Drinking Waters from the Paraiba Do Sul – Guandu River System, Rio De Janeiro State, Brazil." Water Science and Technology 19, no. 7 (July 1, 1987): 1181–83. http://dx.doi.org/10.2166/wst.1987.0006.

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The main goals of the present work are the determination of the critical metals in the Paraiba do Sul - Guandu River System (PSR-GR), and the analysis of tap waters supplied to local cities as well as the city of Rio de Janeiro, to evaluate the metal pollution. Results show that four metals (Pb, Cu, Cr and Zn) out of eight released by the local industrial area are the critical metals in the PSR-GR system. Suspended particles are the main compartment in transporting these metals downstream. Analysis of the performance of tap water treatment plants pointed out the main parameter for these treatment plants is the retention of suspended particles. Iron and manganese had the highest concentrations.

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Sitte, Jana, Denise M. Akob, Christian Kaufmann, Kai Finster, Dipanjan Banerjee, Eva-Maria Burkhardt, Joel E. Kostka, Andreas C. Scheinost, Georg Büchel, and Kirsten Küsel. "Microbial Links between Sulfate Reduction and Metal Retention in Uranium- and Heavy Metal-Contaminated Soil." Applied and Environmental Microbiology 76, no. 10 (April 2, 2010): 3143–52. http://dx.doi.org/10.1128/aem.00051-10.

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ABSTRACT Sulfate-reducing bacteria (SRB) can affect metal mobility either directly by reductive transformation of metal ions, e.g., uranium, into their insoluble forms or indirectly by formation of metal sulfides. This study evaluated in situ and biostimulated activity of SRB in groundwater-influenced soils from a creek bank contaminated with heavy metals and radionuclides within the former uranium mining district of Ronneburg, Germany. In situ activity of SRB, measured by the 35SO4 2− radiotracer method, was restricted to reduced soil horizons with rates of ≤142 ± 20 nmol cm−3 day−1. Concentrations of heavy metals were enriched in the solid phase of the reduced horizons, whereas pore water concentrations were low. X-ray absorption near-edge structure (XANES) measurements demonstrated that ∼80% of uranium was present as reduced uranium but appeared to occur as a sorbed complex. Soil-based dsrAB clone libraries were dominated by sequences affiliated with members of the Desulfobacterales but also the Desulfovibrionales, Syntrophobacteraceae, and Clostridiales. [13C]acetate- and [13C]lactate-biostimulated soil microcosms were dominated by sulfate and Fe(III) reduction. These processes were associated with enrichment of SRB and Geobacteraceae; enriched SRB were closely related to organisms detected in soils by using the dsrAB marker. Concentrations of soluble nickel, cobalt, and occasionally zinc declined ≤100% during anoxic soil incubations. In contrast to results in other studies, soluble uranium increased in carbon-amended treatments, reaching ≤1,407 nM in solution. Our results suggest that (i) ongoing sulfate reduction in contaminated soil resulted in in situ metal attenuation and (ii) the fate of uranium mobility is not predictable and may lead to downstream contamination of adjacent ecosystems.

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Clej (Slave), Dumitra Daniela, Ioana Lavinia Ardelean, and Gheorghe Nechifor. "Applicability of Ferromagnetic Nanoparticles in the Retention of Heavy Metals from Aqueous Solutions." Revista de Chimie 68, no. 6 (July 15, 2017): 1320–24. http://dx.doi.org/10.37358/rc.17.6.5666.

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In this paper are presented the experimental results obtained in the study of applicability of ferromagnetic nanoparticles in the retention of heavy metals from aqueous solutions. The influence of magnetic nanoparticles based on iron, cobalt and nickel on turbidity, pH, permanganate index, aluminum, copper, cadmium and lead was studied. The study shows that conventional water treatment systems combined with acrylic polymer can be improved by adding magnetic nanoparticles. Experimental data has shown that the presence of magnetic nanoparticles based on iron, cobalt and/or nickel increases the efficiency of the treatment system and is reflected by all analyzed parameters.

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Journal articles on the topic 'Retention of heavy metals'

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