Showing papers on "Bioaccumulation published in 2014"
TL;DR: This review addresses the systemic pathophysiology of individual organ systems associated with mercury poisoning through eating contaminated fish, seafood, and wildlife which have been exposed to mercury through ingestion of contaminated lower organisms.
Abstract: Mercury exists naturally and as a man-made contaminant. The release of processed mercury can lead to a progressive increase in the amount of atmospheric mercury, which enters the atmospheric-soil-water distribution cycles where it can remain in circulation for years. Mercury poisoning is the result of exposure to mercury or mercury compounds resulting in various toxic effects depend on its chemical form and route of exposure. The major route of human exposure to methylmercury (MeHg) is largely through eating contaminated fish, seafood, and wildlife which have been exposed to mercury through ingestion of contaminated lower organisms. MeHg toxicity is associated with nervous system damage in adults and impaired neurological development in infants and children. Ingested mercury may undergo bioaccumulation leading to progressive increases in body burdens. This review addresses the systemic pathophysiology of individual organ systems associated with mercury poisoning. Mercury has profound cellular, cardiovascular, hematological, pulmonary, renal, immunological, neurological, endocrine, reproductive, and embryonic toxicological effects.
743 citations
TL;DR: Different species of fish showed inter-specific variation of metals, as well as variations between fish from the same species, which contributed to the contribution of potential factors that affected metals' uptake, like age, geographical distribution and species' specific factors.
Abstract: The concentrations of heavy metals (Cu, Zn, Pb, Cd, Fe and Mn) were measured in the liver, gills and muscles of fourteen benthic and pelagic fish species collected from three main landing areas (Shalateen, Hurghada and Suez) in the Egyptian Red Sea. The levels of heavy metals varied significantly among fish species and organs. As expected, muscles always possessed the lowest concentrations of all metals. In most studied fish, the liver was the target organ for Cu, Zn and Fe accumulation. Pb and Mn, however, exhibited their highest concentrations in the gills. Different species of fish showed inter-specific variation of metals, as well as variations between fish from the same species. These differences were discussed for the contribution of potential factors that affected metals' uptake, like age, geographical distribution and species' specific factors. Generally, recorded metal concentrations were within the range or below the levels in similar species from global studies. The concentration of metals in the present fish muscles were accepted by the international legislation limits and are safe for human consumption.
356 citations
TL;DR: It is found that juvenile turbot bioconcentrated and biotransformed BDE-47 was similar in fish from all treatment groups, and a stepwise debromination of Bde-47 to BDE -28 is demonstrated, demonstrating the risk of its bioaccumulation in the marine environment.
Abstract: Polybrominated diphenyl ethers (PBDEs) are a class of global flame retardants whose residues have markedly increased in fish and human tissues during the last decade. They belong to persistent and toxic contaminants which need more attention and toxicological study as their degradation in the environment is not well understood. This study characterizes 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) bioconcentration, elimination and biotransformation in juvenile turbot Psetta maxima, in order to evaluate the risk of its bioaccumulation in the marine environment. During this study, juvenile turbot were exposed to environmentally relevant BDE-47 concentrations from 0.001 to 1 μg/L for 16 days via aqueous exposure. This study found that juvenile turbot bioconcentrated and biotransformed BDE-47. There was no difference in standard length or weight between control and exposed fish. Uptake and elimination of BDE-47 by the turbot during exposure were examined in controlled laboratory experiments. Bioconcentration of BDE-47 was similar in fish from all treatment groups. Bioconcentration was rapid and increased with exposure time, since the bioconcentration factor (BCF) was higher. However, elimination was slower in comparison and low elimination was detected after 10 days in clean water. BDE-47 concentration in water influences the BCF. Half-life ranged between 37 and 108 days and theoretical times t
90 could range from 120 to 358 days. The present study demonstrates a stepwise debromination of BDE-47 to BDE-28.
318 citations
TL;DR: More comprehensive approaches for the evaluation of environmental (ERA) and human health risk assessment (HRA) are included and analytical methods required to detect bioaccumulation of pharmaceuticals are discussed.
289 citations
01 Jan 2014
TL;DR: The heavy metals chiefly include Pb, Hg, Cd, Cr, Cu, Zn, Mn, Ni, Ag, etc. are considered most toxic to humans, animals, fishes and environment.
Abstract: The heavy metals chiefly include Pb, Hg, Cd, Cr, Cu, Zn, Mn, Ni, Ag, etc. The heavy metals, viz., As, Cd, Pb and Hg are considered most toxic to humans, animals, fishes and environment. Excessive concentrations of heavy metals are detrimental. They destabilize ecosystems because of their bioaccumulation in organisms, and toxic effects on biota and even death in most living beings. All heavy metals, in spite some of them are essential micronutrients, have their toxic effects on living organisms via metabolic interference and mutagenesis. The bioaccumulation of toxic metals can occur in the body and food chain. So, the toxic metals generally exhibit chronic toxicity. The heavy metals like Pb and Hg have significant toxic effects. The heavy metals are important pollutants for fishes, because these are not eliminated from aquatic systems by natural methods, such as organic pollutants, and are enriched in mineral organic substances. Occurrence of heavy metals differs in fishes, depending on their age, development and other physiological factors. Among animal species, the fishes are inhabitants which can be highly affected by these toxic pollutants. Heavy metals can have toxic effects on different organs. They can enter into water via drainage, atmosphere, soil erosion and all human activities by different ways. As the heavy metals concentrated more in the environment, they enter biogeochemical cycle, leading to toxicity.
270 citations
TL;DR: It is concluded that the two prevailing hypotheses for the mechanisms that control the bioaccumulation of perfluorinated alkyl acids need not be mutually exclusive, but that protein interactions are needed to explain some important features of PFAA bio Accumulation.
Abstract: In this review, we consider the two prevailing hypotheses for the mechanisms that control the bioaccumulation of perfluorinated alkyl acids (PFAAs). The first assumes that partitioning to membrane phospholipids, which have a higher affinity for charged species than neutral storage lipids, can explain the high bioaccumulation potential of these compounds. The second assumes that interactions with proteins—including serum albumin, liver fatty acid binding proteins (L-FABP), and organic anion transporters—determine the distribution, accumulation and half-lives of PFAAs. We consider three unique phenomena to evaluate the two models: (1) observed patterns of tissue distribution in the laboratory and field, (2) the relationship between perfluorinated chain length and bioaccumulation, and (3) species- and gender-specific variation in elimination half-lives. Through investigation of these three characteristics of PFAA bioaccumulation, we show the strengths and weaknesses of the two modeling approaches. We conclud...
236 citations
TL;DR: The log-transformed concentrations of PAHs and OPAHs in muscles, guts+gills were significantly correlated with their octanol-water partitioning coefficients, strongly suggesting that equilibrium partitioning from water/sediment into fish tissue was the main mechanism of bioaccumulation.
200 citations
TL;DR: SSBC is suggested to be a candidate for soil amendment that offers advantages over SS in terms of PAH/PTE bioaccumulation mitigation and conversion of SS to SS biochar significantly decreased PAH and available PTE concentrations.
176 citations
TL;DR: Long-term low dose exposure of heavy metals may play a key role in tumorigenesis, and it may not be necessary to accumulate a high concentration of heavy metal in the human body for those metals to induce tumorsigenesis.
159 citations
TL;DR: The trophic magnification factor of ∑SCCPs was determined to be 2.38 in the zooplankton-shrimp-fish food web, indicating biomagnification potential of SCCPs in the marine ecosystem, and the TMF values of individual congener groups significantly correlated with their log KOW values.
Abstract: Short chain chlorinated paraffins (SCCPs) are under the evaluation for inclusion into the Stockholm Convention on persistent organic pollutants. However, information on their bioconcentration and biomagnification in marine ecosystems is unavailable, limiting the evaluation of their ecological risks. In this study, seawater, sediment, zooplankton, invertebrates, and fishes collected from Liaodong Bay, Bohai Sea, North China were analyzed to investigate the residual level, congener group profile, bioaccumulation, and trophic transfer of SCCPs in a marine food web. The total concentrations of SCCPs ranged from 4.1 to 13.1 ng L–1 in seawater, 65 to 541 ng g–1 (dw) in sediment, and 86 to 4400 ng g–1 (ww) in organisms. Correspondence analysis indicated the relative enrichment of C10Cl5 and C11Cl5 formula groups in most aquatic organisms. Both the logarithm bioaccumulation factors (log BAFs: 4.1–6.7) and biota–sediment accumulation factors (BSAFs: 0.1–7.3) of individual congeners implied the bioaccumulation of S...
153 citations
TL;DR: The results suggest that the nature of the pristine coatings as a determinant of hazard may be greatly reduced once CeO2-NPs enter the environment and are coated with NOM.
Abstract: The objective of this study was to investigate the role of the CeO2 nanoparticle (NP) surface charge and the presence of natural organic matter (NOM) in determining bioavailability and toxicity to the model soil organism Caenorhabditis elegans. We synthesized CeO2-NPs functionalized with positively charged, negatively charged, and neutral coatings. The positively charged CeO2-NPs were significantly more toxic to C. elegans and bioaccumulated to a greater extent than the neutral and negatively charged CeO2-NPs. Surface charge also affected the oxidation state of Ce in C. elegans tissues after uptake. Greater reduction of Ce from Ce (IV) to Ce (III) was found in C. elegans, when exposed to the neutral and negatively charged relative to positively charged CeO2-NPs. The addition of humic acid (HA) to the exposure media significantly decreased the toxicity of CeO2-NPs, and the ratio of CeO2-NPs to HA influenced Ce bioaccumulation. When the concentration of HA was higher than the CeO2-NP concentration, Ce bioaccumulation decreased. These results suggest that the nature of the pristine coatings as a determinant of hazard may be greatly reduced once CeO2-NPs enter the environment and are coated with NOM.
TL;DR: This study summarizes the empirical evidence that is currently available of those compounds in the Arctic that are not commonly included in chemical monitoring programmes and focuses on novel flame retardants, e.g. alternatives to the banned polybrominated diphenyl ethers (PBDEs), current-use pesticides and various other compounds.
TL;DR: This investigation indicated that various levels of heavy metals exist in the fish species sampled, but those concentrations are within the maximum residual levels recommended by the European Union and FAO/WHO and therefore, fish caught in Mumbai Harbor can be considered safe for human consumption.
TL;DR: The metal bioaccumulation pattern in fish was weakly related to the metal concentrations in the environment with the exception of Hg at the most polluted location, partly explained by the different metabolic role of essential and non-essential elements and the influence of other factors such as species' ecology and individual traits in the bio Accumulation of most metals.
TL;DR: Metal loads were comparable with literature data from contaminated sites, often exceeding recommended European Environmental Quality Standards and the slopes of these relationships were often significantly heterogeneous, a fact barely acknowledged in the literature, and were often negative.
TL;DR: All hazard ratio values reported for PFOS and perfluorooctanoate (PFOA) were less than unity, suggesting that the detected levels would not cause any immediate health effects to the people in Taihu Lake region through the consumption of shrimps and fish.
TL;DR: The occurrence as well as the spatial and temporal variations of some common prescribed pharmaceuticals in the Suquía River basin (Córdoba, Argentina) and the bioconcentration of two of them in Gambusia affinis, a widely distributed fish species inhabiting the river basin are reported.
TL;DR: In this paper, the mean concentrations of metals in sediment, bivalves, and P. australis (roots and leaves) decreased in the following order: Fe > Mn > Zn > Cu > Cr > Ni > Pb > Co > Cd.
Abstract: Urbanization can considerably affect water reservoirs by, inter alia, input, and accumulation of contaminants including metals. Located in the course of River Cybina, Maltanski Reservoir (Western Poland) is an artificial shallow water body built for recreation and sport purposes which undergoes restoration treatment (drainage) every 4 years. In the present study, we demonstrate an accumulation of nine metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn) in water, sediment, three bivalve species (Anodonta anatina, Anodonta cygnea, Unio tumidus), and macrophyte Phragmites australis collected before complete drainage in November 2012. The mean concentrations of metals in the sediment, bivalves, and P. australis (roots and leaves) decreased in the following order: Fe > Mn > Zn > Cu > Cr > Ni > Pb > Co > Cd. A considerably higher bioconcentration of metals was observed in samples collected from the western and southern sites which undergo a higher degree of human impact. Sediments were found to be a better indicator of metal contamination than water samples. Interspecific differences in levels of metal accumulation were found between investigated unionids. U. tumidus accumulated higher levels of Cr, positively correlated with ambient concentrations, predisposing this species as a potential bioindicator of this metal in aquatic environments. On the other hand, species of Anodonta genus demonstrated higher accumulation of Cu and Cd. Positive correlations were found between Pb content in the sediments and tissues of all three bivalve species. In P. australis, metals were largely retained in roots except for Cd and Pb for which higher concentrations were found in leaves suggesting additional absorption of these metals from aerial sources. P. australis and bivalve from the Maltanski Reservoir may be a potential source of toxic metals for animals feeding upon them and contribute to further contamination in the food chain.
TL;DR: The results suggest that frequent consumption of these four fish species may pose health risks to local population, indicating a similar pollution source for these PFASs.
TL;DR: It is demonstrated that the biological uptake of Hg in lakes is determined by binding thresholds on DOC, a water quality variable predicted to change markedly with future environmental change.
Abstract: Dissolved organic carbon (DOC) is known to affect the Hg cycle in aquatic environments due to its overriding influence on complexation, photochemical, and microbial processes, but its role as a mediating factor in the bioaccumulation of Hg in aquatic biota has remained enigmatic. Here, we examined 26 tundra lakes in Canada’s western Arctic that span a large gradient of DOC concentrations to show that total Hg (HgT) and methyl mercury (MeHg) accumulation by aquatic invertebrates is defined by a threshold response to Hg-DOC binding. Our results showed that DOC promotes HgT and MeHg bioaccumulation in tundra lakes having low DOC ( DOC TC), consistent with bioaccumulation results in a companion paper (this issue) using a microbial bioreporter. Chemical equilibrium modeling showed that Hg bioaccumulation factors were elevated when Hg was associated mainly to fulvic acids, but became...
TL;DR: The consequence of the presence of more hydrophobic mono- and dibrominated EE2 in the environment remains to be further investigated, as these products were shown to have a lower estrogenic potency but are expected to be a higher bioaccumulation potential and to be more toxic than the mother compound.
Abstract: Bioconcentration and transformation of the potent and persistent xeno-estrogen 17α-ethinylestradiol (EE2) by organisms at the basis of the food web have received only little research attention. In this study, uptake, elimination, and biotransformation of radiolabeled EE2 ((14)C-EE2) by the freshwater green alga Desmodesmus subspicatus were investigated. The alga highly incorporated radioactivity following (14)C-EE2 exposure. Up to 68% of the test compound was removed from the medium by D. subspicatus within a rather short time period (72 h C(algae)/C(water): 2200 L/kg wet weight). When the algae were transported to clear medium, a two-stage release pattern was observed with an initially quick elimination phase following slower clearance afterward. Interestingly, D. subspicatus brominated EE2 when bromide was available in the medium, a transformation process demonstrated to occur abiotically but not by algae. The consequence of the presence of more hydrophobic mono- and dibrominated EE2 in the environment remains to be further investigated, as these products were shown to have a lower estrogenic potency but are expected to have a higher bioaccumulation potential and to be more toxic than the mother compound.
TL;DR: It is estimated that 80-90% of the bioaccumulated (65)Cu concentration in L. stagnalis originated from the ( 65)CuO NPs, suggesting that dissolution had a negligible influence on Cu uptake from the NPs under the authors' experimental conditions.
Abstract: The incidental ingestion of engineered nanoparticles (NPs) can be an important route of uptake for aquatic organisms. Yet, knowledge of dietary bioavailability and toxicity of NPs is scarce. Here we used isotopically modified copper oxide ((65)CuO) NPs to characterize the processes governing their bioaccumulation in a freshwater snail after waterborne and dietborne exposures. Lymnaea stagnalis efficiently accumulated (65)Cu after aqueous and dietary exposures to (65)CuO NPs. Cu assimilation efficiency and feeding rates averaged 83% and 0.61 g g(-1) d(-1) at low exposure concentrations (<100 nmol g(-1)), and declined by nearly 50% above this concentration. We estimated that 80-90% of the bioaccumulated (65)Cu concentration in L. stagnalis originated from the (65)CuO NPs, suggesting that dissolution had a negligible influence on Cu uptake from the NPs under our experimental conditions. The physiological loss of (65)Cu incorporated into tissues after exposures to (65)CuO NPs was rapid over the first days of depuration and not detectable thereafter. As a result, large Cu body concentrations are expected in L. stagnalis after exposure to CuO NPs. To the degree that there is a link between bioaccumulation and toxicity, dietborne exposures to CuO NPs are likely to elicit adverse effects more readily than waterborne exposures.
TL;DR: The results indicated that plants in polluted environments are enriched in heavy metals relative to those in pristine environments, this is mainly caused by traffic emissions and coal combustion.
TL;DR: In this article, the bioavailability, toxicity, and transfer of silver nanoparticles (AgNPs) in comparison with AgNO3 in two model food chain organisms: the alga Chlamydomonas reinhardtii and the grazing crustacean Daphnia magna were evaluated.
Abstract: This study assessed the bioavailability, toxicity, and transfer of silver nanoparticles (AgNPs) in comparison with AgNO3 in two model food chain organisms: the alga Chlamydomonas reinhardtii and the grazing crustacean Daphnia magna. The effects of phosphate, a potential Ag(+)-binding ligand and a determinant of phytoplankton productivity, were evaluated. Nano Ag derived from coated AgNPs and AgNO3 was accumulated at similar concentrations into microalgae during high phosphate treatment, but AgNO3 accumulation was increased by low phosphate availability. After feeding on Ag-containing algae, D. magna equally accumulated AgNO3 and nano-derived Ag. There were significant reductions in feeding when D. magna were fed Ag-contaminated algae, with the AgNO3, low phosphate-exposed cells being ingested the least. Nutritional quality characteristics including fatty acid and trace nutrient content were similar in all algal samples, indicating that feeding reduction is specifically due to the presence of Ag, with AgNO3 being more toxic than nano Ag.
TL;DR: Investigation into GSH metabolism and its role in ameliorating metal toxicity can offer important information on the application of the microorganism for wastewater treatment.
Abstract: Phanerochaete chrysosporium are known to be vital hyperaccumulation species for heavy metal removal with admirable intracellular bioaccumulation capacity. This study analyzes the heavy metal-induced glutathione (GSH) accumulation and the regulation at the intracellular heavy metal level in P. chrysosporium. P. chrysosporium accumulated high levels of GSH, accompanied with high intracellular concentrations of Pb and Cd. Pb bioaccumulation lead to a narrow range of fluctuation in GSH accumulation (0.72-0.84 μmol), while GSH plummeted under Cd exposure at the maximum value of 0.37 μmol. Good correlations between time-course GSH depletion and Cd bioaccumulation were determined (R (2) > 0.87), while no significant correlations have been found between GSH variation and Pb bioaccumulation (R (2) < 0.38). Significantly, concentration-dependent molar ratios of Pb/GSH ranging from 0.10 to 0.18 were observed, while molar ratios of Cd/GSH were at the scope of 1.53-3.32, confirming the dominant role of GSH in Cd chelation. The study also demonstrated that P. chrysosporium showed considerable hypertolerance to Pb ions, accompanied with demand-driven stimulation in GSH synthesis and unconspicuous generation of reactive oxygen stress. GSH plummeted dramatically response to Cd exposure, due to the strong affinity of GSH to Cd and the involvement of GSH in Cd detoxification mechanism mainly as Cd chelators. Investigations into GSH metabolism and its role in ameliorating metal toxicity can offer important information on the application of the microorganism for wastewater treatment.
TL;DR: The significance of using a set of integrated biomarker and advocate to include these parameters in National Water Quality Monitoring Program in areas potentially polluted with metals to assess the health of the ecosystem is highlighted.
Abstract: The evaluation of metal’s toxicity in freshwater is one of the imperative areas of research and there is an emergent concern on the development of techniques for detecting toxic effects in aquatic animals. Oxidative stress biomarkers are very useful in assessing the health of aquatic life and more in depth studies are necessary to establish an exact cause effect relationship. Therefore, to study the effectiveness of this approach, a laboratory study was conducted in the fish Labeo rohita as a function of hexavalent chromium and the toxicity indices using a battery of oxidative stress biomarkers such as catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GR) in the liver, muscle, gills, and brain have been studied along with biometric parameters, behavioral changes, and Cr bioaccumulation. A significant increased HSI was observed in contrast to CF which reduced significantly. SOD, CAT, and GR activity increased significantly in all the tissues of treated fishes. The bioaccumulation of Cr was highest in liver followed by gills, muscle, and brain. This study highlights the significance of using a set of integrated biomarker and advocate to include these parameters in National Water Quality Monitoring Program in areas potentially polluted with metals to assess the health of the ecosystem.
TL;DR: The co-presence of wheat and earthworms enhanced the bioavailability of PFASs in soil and increased the bioaccumulation in wheat of PFCAs containing seven or less perfluorinated carbons, and decreased bioaccUMulation of PFSAs.
TL;DR: Remarkably, little fractions of the internalized radioactivity were detected in the blood and muscle tissue of exposed fish, suggesting biomagnification of MWCNTs in the food chain is possible and should be a subject of further research.
Abstract: No data on the bioaccumulation and distribution of multiwalled carbon nanotubes (MWCNTs) in aquatic vertebrates is available until now. We quantified uptake and elimination of dispersed radiolabeled MWCNTs ((14)C-MWCNT; 1 mg/L) by zebrafish (Danio rerio) over time. The influences of the feeding regime and presence of dissolved organic carbon (DOC) on accumulation of the nanomaterial were determined. The partitioning of radioactivity to different organs and tissues was measured in all experiments. A bioaccumulation factor of 16 L/kg fish wet weight was derived. MWCNTs quickly associated with the fish, and steady state was reached within 1 day. After transfer to clear medium, MWCNTs were quickly released to the water phase, but on average 5 mg of MWCNTs/kg fish dry weight remained associated with the fish. The nanomaterial mainly accumulated in the gut of all fish. Feeding led to lower internal concentrations due to facilitated elimination via the digestive tract. In the presence of DOC, 10-fold less was taken up by the fish after 48 h of exposure compared to without DOC. Quick adhesion to and detachment from superficial tissues were observed. Remarkably, little fractions of the internalized radioactivity were detected in the blood and muscle tissue of exposed fish. The part accumulated in these fish compartments remained constant during the elimination phase. Hence, biomagnification of MWCNTs in the food chain is possible and should be a subject of further research.
TL;DR: Findings indicate that silver ions are more toxic than Ag-NP and have a higher potential to accumulate in F. candida.
Abstract: The growing use of silver nanoparticles (Ag-NP) triggered an increasing interest in their environmental fate and possible ecotoxicological impacts. To investigate the potential risk of Ag-NP to soil organisms, the springtail Folsomia candida was exposed to Ag-NP (reported diameter size 3–8 nm) and AgNO3 in Lufa 2.2 natural soil for 28 days to determine effects on survival and reproduction. Also, the kinetics of uptake and elimination of Ag were studied for F. candida exposed in Lufa 2.2 soil to Ag-NP (at 168 mg Ag/kg dry soil) and AgNO3 (at 30 and 60 mg Ag/kg dry soil). AgNO3 was toxic with an LC50 was 284 mg Ag/kg dry soil for effects on survival and EC10 and EC50 values of 47.6 and 99.5 mg Ag/kg dry soil, respectively for the effect on reproduction. These values did correspond with porewater concentrations of 0.801, 0.042 and 0.082 mg Ag/l, respectively. No effects on survival and reproduction of Ag-NP were observed up to 673 mg Ag/kg dry soil, although porewater concentration was similar to the EC50 for AgNO3. Exposure to both Ag forms caused a fast uptake of Ag, but the Ag elimination rate was significantly higher for Ag-NP than for AgNO3. Bioaccumulation factor was higher for AgNO3 (on average 5.64) than for Ag-NP (1.12). These findings indicate that silver ions are more toxic than Ag-NP and have a higher potential to accumulate in F. candida.
Journal Article•
TL;DR: In this paper, the potentials of biosorption and bioaccumulation for removal of heavy metals from the contaminated environment were analyzed and selected biosorbents applied in the process of removing heavy metals.
Abstract: Biosorption and bioaccumulation can be applied to remedy environments contaminated with heavy metals as complementary methods to currently used physical and chemical methods. The overall goal of this work was to analyze potentials of biosorption and bioaccumulation for removal of heavy metals from the contaminated environment. The most frequently used methods for removal of heavy metals from water and wastewater were presented. Select biosorbents applied in the process of removal of heavy metals from contaminated environment were characterized. Factors that influence biosorption were analyzed. Also, methods for improving the efficiency of removal of heavy metals with biosorbents through biomass modification and immobilization were presented. Types of reactors applied in the processes of biosorption and bioaccumulation were described. It was found that removal of heavy metals from the environment with biotechnological methods should consider a number of physicochemical factors such as temperature, pH, contact time of biomass, and a solution containing metals, concentration and age of biomass, and toxicity when living microorganisms are applied. Improving the efficiency of removal of metals can be performed through physical and chemical modifications and immobilization of biomass. The most frequently applied reactors include: stirred tank reactors, fixed-bed, reactors and fluidized-bed reactors.