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Growing concerns over metal pollution highlight the need for effective remediation strategies. This study evaluates the accumulation capacity and tolerance of Melia azedarach and Ailanthus altissima for trace elements (Pb, Zn, and Cu), aiming to assess their phytoremediation potential. Three-month-old seedlings of both species, grown from seeds collected at the Touissit mine site, were cultivated in perlite and irrigated with Hoagland nutrient solution. Plants were exposed to various concentrations of metal salts—Pb(NO3)2 (8, 40, and 80 mg.L−1), ZnSO4 (8, 40, and 80 mg.L−1), and CuSO4 (2, 10, and 20 mg.L−1)—over a 90-day period. Growth, biomass, metal accumulation, chlorophyll, and carotenoid contents were measured. Results indicate that M. azedarach exhibited enhanced biomass under Pb exposure, suggesting notable tolerance and potential for phytoremediation. Conversely, A. altissima showed an initial increase in biomass at low Pb levels, followed by a significant reduction at higher concentrations. Both species demonstrated decreased biomass under Zn and Cu treatments, with varying degrees of sensitivity. Notably, A. altissima accumulated significant levels of Pb, Zn, and Cu, particularly in the roots, indicating high phytoremediation potential. While M. azedarach also accumulated metals, levels were comparatively lower. Both species maintained chlorophyll content under metal stress, indicating resilience. Overall, this hydroponic screening highlights the considerable capacities of M. azedarach and A. altissima for Pb, Zn, and Cu tolerance, with A. altissima showing particularly high potential for Pb phytostabilization. [ABSTRACT FROM AUTHOR]

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Purpose: This study aims to assess the feasibility and efficiency of electrokinetic (EK) remediation of soil contaminated with As, Cd, Cu, and Pb using the biodegradable chelator N, N-bis(carboxymethyl)-tetrasodium salt (GLDA) at the pilot scale. Materials and methods: The experiments were performed under a constant voltage (40 V) in an EK reactor (100 cm (length) × 50 cm (width) × 25 cm (height)) for over 100 days using various enhancement strategies. The current, electroosmotic flow (EOF), microstructure, mineral composition of the soil samples (before and after EK remediation), removal efficiencies, chemical forms, and ecotoxicity risks of As, Cd, Cu, and Pb were determined. Results and discussion: The results showed gradual decreases in the electrical current and EOF over time. The spatial distribution of As, Cd, Cu, and Pb in the soil solution and electrolyte revealed that the removed metals primarily accumulated in anolytes. The soil As, Cd, and Cu contents, especially near the anode, showed gradual reductions. The total removal efficiencies of As, Cd, Cu, and Pb were 49.4%, 44.0%, 53.6%, and 36.6%, respectively. Overall, the ecotoxicity risks of the remaining As, Cd, Cu, and Pb were below the initial values. A soil microstructure and mineral composition analysis indicated that the GLDA-enhanced EK technology effectively removed As, Cd, Cu, and Pb by dissolving soil minerals and breaking chemical bonds. The unit energy consumption ranged from 1.25 to 1.83 kW·h/t/%, indicating lower or comparable values to the data in the literature. Conclusions: The biodegradable chelator, GLDA, has been shown to remove different types of potentially toxic elements using enhancement strategies on a pilot scale with low unit energy consumption. Arsenic migrated to the anode in the anionic form, and the complexes formed by Cd, Cu, and Pb with GLDA were negatively charged and moved toward the cathode. After the EK treatment, the ecotoxicity risks of As, Cd, Cu, and Pb decreased with a reduction in the contents and the chemical form changes of As, Cd, Cu, and Pb. [ABSTRACT FROM AUTHOR]

Fish meat is recommended for consumption as a source of protein, essential unsaturated fatty acids, and fat-soluble vitamins, unfortunately it can also be a source of dangerous contaminants. The aim of the study was to assessment the level of Zn, Cu and Pb in water and bottom sediments collected in summer and autumn from the Koronowo Reservoir and the Wierzchucińskie Duże Lake and in the tissues of perch (Perca fluviatilis L.) and rudd (Scardinius erythrophtalmus L.) for health risk assessment of potential consumers. Metals accumulated in the tissues in the following order: meat, liver and gills: Zn > Cu > Pb. Of the four factors taken into account, such as: type of tissue, fish species, catching season and place of catching, the first one determined the degree of metal accumulation to the greatest extent. The high level of Pb in muscle tissue was determined by the content of this metal in tissue collected from rudd from Wierzchucińskie Duże Lake in the summer (0.383 mg kg−1 ww). The bioconcentration factor (BCF) of Pb, Zn and Cu in all tissues of analysed fish was much higher from water than from sediments. The highest value of metal pollution index (MPI) in the meat (1.42), liver (12.97), and gills (8.49) was calculated for summer-caught fish. The research indicated that consumption of 100 g of fish meat could meet daily requirement for Zn up to 26.3 % and for Cu in 16.4 %. The potential risk of Pb consumption according to RDA is as much as 2.4 %.

Environmental factors, such as trace elements and blood lead, have been implicated in the heterogeneity of children with attention deficit hyperactivity disorder (ADHD). This research aimed to investigate the relationship between blood trace elements and cognitive function as well as behavioral problems in children aged 4–12 years diagnosed with ADHD. In this study, we recruited 146 children with ADHD and 91 neurotypical controls matched for age and gender. We used atomic absorption spectrometry to measure the concentrations of Cu, Zn, Ca, Mg, Fe, and Pb in the whole blood. The Conners Parent Rating Scale (CPRS) and Wechsler intelligence tests were employed to evaluate cognitive function and behavioral problems. Compared with controls, children with ADHD exhibited higher levels of Pb. Pb levels indicated a negative correlation with the verbal comprehension index and the full intelligence scale. Cu levels indicated a negative correlation with the verbal comprehension index but positively correlated with conduct, learning, and impulsive-hyperactivity problems. In addition, Fe levels indicated a positive correlation with psychosomatic symptoms. Wechsler intelligence results indicated substantially higher scores in children with normal Zn levels than those outside the reference range. These results indicate a correlation between the present of Pb, Cu, Fe, and Zn in the blood of Chinese children with ADHD and cognitive function and behavioral problems. [ABSTRACT FROM AUTHOR]

The coast of Tanjung Mas, Semarang City, is an industrial area used by the community to cultivate milkfish using stick-net pens. Furthermore, heavy metal contamination such as Cr, Cd, Cu, and Pb potentially disrupts milkfish meat's growth, quality, and safety. This study aims to determine heavy metals concentration in the waters and milkfish meat in stick-net pens cultivation in Tanjung Mas, Semarang City. The study was conducted using exploration, with five observation sites representing household waste disposal flow, industrial discharge, open sea, and intermediate areas. The observation sites were selected based on the milkfish cultivation activity. The sample and data, including water, milkfish, and environmental factors (temperature, pH, salinity, water current, and dissolved oxygen), were collected three times every two weeks. The heavy metals were detected using Atomic Absorption Spectrometry (AAS). The highest heavy metal concentration is Cr, which ranges from 1.70 ± 0.32 ppm to 2.36 ± 0.63 ppm in milkfish and 2.77 ± 0.65 ppm to 3.05 ± 0.58 ppm in the environment. The heavy metals contamination in Semarang City's water areas is still relatively low and has no impact on milkfish growth. Industrial waste, mainly heavy metals, potentially threatens the stick-net pens cultivation model developed by the community in Semarang City. This study can be used as an input for mitigation and adaptive action in anticipating future environmental changes and maintaining their business sustainability. [ABSTRACT FROM AUTHOR]

In this study, biosorption potential of nine epiphytic bacteria isolated from the rhizosphere of Lepironia articulata and Scirpus grossus were assessed. Identification of the isolated epiphytic rhizobacteria using 16S rRNA analysis showed species belonging to the four genera of Bacillus, Enterobacter, Aeromonas, and Chromobacterium. Batch biosorption studies were carried out to assess the capacity of the isolated bacteria to act as Pb and Cu biosorbents. Different initial concentrations of the two heavy metals (50, 100, 200, 300, and 400 ppm) were used to determine the ability of the biosorbent to reach a tolerance level and then calculate the percentage of biosorption with respect to 0.1 g dry weight. Initial concentration of Pb and Cu exposed showed that the isolated bacteria have high tolerance up to 400 ppm. Bacteria prefer Pb ions over Cu, which is indicated by higher removal of Pb in all tested reactors. Bacillus sp. (coded Sc1) showed the highest biosorption capacity with 100% Pb and 97% Cu removal. [ABSTRACT FROM AUTHOR]

The concentrations of heavy metals Cu, Zn, Cd, and Pb in the leaves of Betula pubescens were analyzed at ten sites along the pollution gradient near the Middle Ural copper smelter. The studies were carried out during the period of moderate emissions (2009) and after their reduction to a minimum (2019). Leaf samples were collected in early and late summer. Cu and Cd showed a strong negative correlation with the distance to the smelter. The interannual differences are most pronounced for Pb, the concentration of which significantly decreased in 2019 at the sites closest to the smelter compared to 2009. In both years, the concentrations of metals in the leaves increased towards the end of the growing season. [ABSTRACT FROM AUTHOR]

This paper presents general research on heavy metal pollution and explains the effect of heavy metal accumulation in the body on blood tests and biochemical assays. This study was conducted at the Faculty of the College of Veterinary Medicine at the University of Tikrit with aim to study the effect of lead, cadmium, copper, and molybdenum poisoning on the properties of blood and biochemical assays. The study divided 45 white male mice into five groups, and a group with distilled water as control group. The lead group (PB) received (0.376) mg/kg lead acetate daily, the Cd group received (0.832) mg/kg cadmium chloride, the Cu group received (37.974) mg/kg copper sulfate, and the Mo group received (5) mg/kg ammonium molybdate. The blood parameters were measured by the Mindray BC-30S CBC device, where the red blood cell count (RBC), white blood cell count (WBC), hemoglobin concentration (HGB), mean corpuscular volume (MCV), hematocrit (HCT), intramuscular hemoglobin (MCH), average group hemoglobin concentration (MCHC), and platelet count (PLT) were checked. Biochemical assays as: blood urea nitrogen (BUN) creatinine (CRE), albumin (ALB), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) were carried out using Cobas 111 C device, Germany. The data were statistically analyzed using the experimental system in the pre-written statistical program Statistical Analysis System (SAS) and the complete random design system (CRD). It was found that there was an increase in the number of white blood cells in the Pb group compared to the control groups, copper, cadmium and Mo groups. Also a decrease in red blood cells in the lead group compared to the control group and other groups was showed, as well as a decrease in HGB compared to the other groups. The decrease of RBC, HGB and HCT may be due to systemic hemolysis. However, in this group was showed rise in WBC, and the cause of this rise is inflammation as a result of the formation of free radicals and oxidation of cell membranes. The results also showed an increase in AST in the Pb, Cu and Cd groups compared to the control group. The kidney tests showed a decrease in albumin in the Pb group compared to the control group, and a significant decrease in BUN in all groups compared to the control group. The results showed that exposure to heavy metals in male mice increased the chance of developing anomalies in the blood system, decreased renal function, and increased liver defects in WBC, blood, and hemoglobin due to hemolysis and irregular liver enzymes. We conclude from the study that exposure to heavy metals can cause blood disorders, liver damage, and kidney failure, regardless of what we advise when assessing the risks associated with exposure to multiple heavy metals. [ABSTRACT FROM AUTHOR]

Among a number of climate-related factors, moisture has the greatest impact on crop productivity. In recent years, certain changes have been observed under conditions of the Forest-Steppe of Ukraine with regard to precipitation - from low to in some cases - abnormally high, which requires the study of their impact on the yield and safety of cereal grain for its forecasted production. The article examined the effect of a high level of soil moisture (256.2-272.5 mm) and a low level (47.4-52.3 mm) during the growing season (germination-earing) of spring barley grain on the accumulation of heavy metals in it and its productivity under the conditions of gray forest soils of the Right Bank Forest Steppe of Ukraine. Spring barley varieties Helios and Caesar were selected for the research. A decrease in the accumulation coefficient at a high level of soil moisture (256.6-272.5 mm) in spring barley grain Pb from 8.3% to 11.3%, Cd - from 35.0% to 35.5%, Zn was established - by 15% and Cu - from 11.2% to 16.6% compared to the low level of soil moisture (47.1 mm - 53.3 mm). At the same time, it was found that with a high level of soil moisture, there is a decrease in the yield of Helios and Caesar spring barley by 18.0% and 14.1%, respectively. [ABSTRACT FROM AUTHOR]

The aim of the study was to investigate and compare the soils of three groups of grassland ecosystems with varying degrees of heavy metal (Cu, Pb, and Zn) pollution as well as estimating of mobility on the basis of calculated mobility indexes (MI) expressed as a percentage of the EDTA-extracted forms of metals in their total content. A total of 55 surface soil samples were collected from various areas of Poland: urban soils, rural soils, and soils along communication routes. Heavy metal concentrations were determined in solutions after wet mineralization (using a mixture of acids) by atomic absorption spectrometry (AAS) with flame atomization. To isolate the mobile forms of metals in soils, a one-step extraction method was used with 0.05-M EDTA solution. The ranges of Cu, Pb, and Zn concentrations in soils were varied, respectively: 6.7–47.6, 61.1–563.9, and 86.4–644.5 mg·kg−1 (A); 5.7–39.8, 13.56–45.71, and 16.3–119.6 mg·kg−1 (B); and 1.0–195.8, 19.2–310.2, and 27.4–894.1 mg·kg−1 (C). The average values of mobility indexes of Cu, Pb, and Zn were at the level of 40.9, 33.5, and 22.2% (A); 23.2, 27.1, and 25.9% (B); and 37.5, 34.3, and 30.7% (C). Studies have shown that metals derived from anthropogenic sources are characterized by greater mobility compared to metals of natural origin (lithological associated with the ground). The inclusion of metal mobility indices in the environmental monitoring strategy may minimize errors in assessing the actual risk associated with the potential uptake of these metals by plants and incorporation into circulation. [ABSTRACT FROM AUTHOR]

Phytomanagement is a concept fit for a bio-based circular economy that combines phytotechnologies and biomass production for non-food purposes. Here, ten annual and perennial industrial non-food crops (Sorghum Biomass 133, Sorghum Santa Fe red, Linum usitatissimum L., Eucalyptus sp., Salix Inger, Salix Tordis, Beta vulgaris L., Phacelia tanacetifolia Benth., Malva sylvestris L., and Chenopodium album L.) were studied under field conditions for phytomanaging a metal (Cd, Cu, Pb, and Zn)-contaminated dredged sediment in the North of France. The crops were selected according to their relevance to pedoclimatic and future climatic conditions, and one or more non-food end-products were proposed for each plant part collected, such as biogas, bioethanol, compost, natural dye, ecocatalyst, and fiber. Based on the soil–plant transfer of metals, eight out of the crops cultivated on field plots exhibited an excluder behavior (bioconcentration factor, BCF < 1), a trait suitable for phytostabilization. However, these crops did not change the metal mobilities in the dredged sediment. The BCF < 1 was not sufficient to characterize the excluder behavior of crops as this factor depended on the total dredged-sediment contaminant. Therefore, a BCF group ranking method was proposed accounting for metal phytotoxicity levels or yield decrease as a complemental way to discuss the crop behavior. The feasibility of the biomass-processing chains was discussed based on these results and according to a survey of available legislation in standard and scientific literature. [ABSTRACT FROM AUTHOR]

The purpose of this work was to study the patterns of Zn, Cu, and Pb distribution in soil aggregates of various size fractions. Materials were Calcic Chernozems and Urbic Technosol of the Rostov agglomeration. Soil samples were passed through sieves with different mesh sizes (dry sieving). For the study, particle size fractions of > 10, 7–5, 5–3, 2–1, and < 0.25 mm were sampled, where the total forms of Zn, Cu, and Pb were examined by means of the X-ray fluorescence method. In the Zn content in both Calcic Chernozems and Urbic Technosol peaks in < 0.25-mm particle size fractions, the concentration decreases as particle size grows. Calcic Chernozems display Cu concentrations in mid-size soil particles of 2–1 and 5–3 mm. In Urbic Technosols, the lowest Cu concentration is typically found in particle size fractions of > 10 mm. Pb in Calcic Chernozems is concentrated in mid-size soil aggregates of 2–1 and 5–3 mm. However, Urbic Technosols tend to accumulate silt-fraction lead (< 0.25 mm). A higher zinc concentration in silt-fraction aggregates found in Urbic Technosols in comparison to Calcic Chernozems highlights the anthropogenic origin of a considerable part of this element's soil pool. Excessively high lead content in UR (urbic) horizons leads to the structure degradation and, consequently, to a transformed overall trend of HM distribution across the soil profile in general. [ABSTRACT FROM AUTHOR]

The direct or indirect discharge of industrial wastewater leads to the high degree of pollution of heavy metals in Chinese natural water resources. The removal of heavy metals sewage is a problem that is exigent to be solved. However, existing heavy metal removal methods are generally found to be too complicated or expensive. Because the waste concrete particles contain cement hydration products and unhydrated cement particles, which have a certain activity and a high specific surface area. This paper tries to use the waste concrete particles as the adsorption material of water polluted by heavy metals. Through the heavy metals leaching test, it is found that the heavy metal leaching capacity is related to the particle size of the waste concrete. The larger the particle size is, the smaller the heavy metal leaching capacity is. Based on the test data and the discharge threshold requirements of the National Comprehensive Sewage Discharge Standard, the optimal selected particle size of the waste concrete particle material is finally determined. Then, by the static adsorption test, the effect of the adsorption time, the adsorbent dosage and the initial mass concentration of heavy metal on the adsorption of heavy metals copper and lead in waste concrete are mainly investigated. The result shows that the adsorption time, waste concrete dosage and initial concentration of heavy metal copper and lead will affect the adsorption properties of waste concrete. With the increase of adsorption time, the adsorption of two heavy metals copper and lead shows a trend of increasing first and then stabilizing. In the first 100 min, the adsorption of copper and lead quickly reached the equilibrium. With the increase of the initial mass concentration of copper and lead, the removal rate of the two heavy metal gradually decreases, and the adsorption capacity gradually increases and then stabilizes. When the initial mass concentration is less than 150 mg/L, the adsorption capacity for heavy metal copper is positively correlated, while heavy metal lead is positively correlated at the initial mass concentration of 200 mg/L. However, with the increase of waste concrete dosage, the removal rate of the two heavy metals copper and lead increases first and then stabilized. The adsorption of heavy metals copper and lead on waste concrete conforms to the Langmiur isothermal adsorption model, and the maximum adsorption capacity obtains 40.75 and 86.73 mg/g respectively; the pseudo-second-order kinetic model is more suitable for describing the adsorption process of heavy metals copper and lead on waste concrete, which indicating that the adsorption rate is controlled by chemisorption. Compared with other common adsorbent materials, the maximum adsorption capacity of heavy metals lead and copper on the waste concrete is much higher than natural zeolite and palygorskite, while the maximum adsorption capacity of heavy metal copper is lower than activated carbon. However, based on the price, the recycling price of waste concrete is still far lower than the market price of activated carbon even if the processing cost caused by crushing. This also reflects that the waste concrete has good adsorption capacity for the heavy metals copper and lead, which can be used as an adsorption material to treat the wastewater containing heavy metals copper and lead. [ABSTRACT FROM AUTHOR]

It has been reported that heavy metals have adverse effects on the immune system. However, the relationship between heavy metal exposure and allergic outcomes remains unclear. This systematic review was conducted to examine whether heavy metal exposure is associated with allergic outcomes during childhood. We performed a systematic search of all relevant articles in Web of Science, EMBASE, and PubMed, from inception through to November 2020. We used odds ratio (OR) and the standard mean differences (SMDs) with 95% confidence intervals (CIs) to present estimates from individual studies. In addition, random-effects meta-analysis was used to pool the data. We also conducted the meta-regression and subgroup analysis to explore potential sources of heterogeneity. After duplicate removal, we finally included 35 articles in the systematic review and meta-analysis from an initial 11,181 articles. The overall results showed that copper (Cu) was associated with asthma (pooled SMD = 1.50, 95% CI = 0.13–2.86); in the subgroup analysis, the results indicated that lead (Pb) was associated with asthma (pooled OR = 6.27, 95% CI = 2.24–17.56), and Cu and Pb were connected with atopic dermatitis (SMD = − 1.05, 95% CI = − 1.45 to − 0.65; SMD = 5.68, 95% CI = 5.05–6.32), respectively. Mercury (Hg) was associated with atopic dermatitis (pooled OR = 1.13, 95% CI = 1.04–1.22) and wheeze (OR = 1.20, 95% CI = 1.05–1.37). The meta-analysis results indicate that Cu might be connected with childhood asthma, but not with other allergic diseases; Hg and Pb may have no association with allergic diseases during childhood. Given some limits observed in the current studies, more prospective cohort studies are still needed to verify our findings. Review registration: PROSPERO CRD42020222167. [ABSTRACT FROM AUTHOR]

The present study investigated the antioxidant enzyme activities (AEA) of ascorbate peroxidase (APX), catalase (CAT), guaiacol peroxidase (GPX), and superoxide dismutase (SOD) as biomarkers of Cu and Pb stress by using Centella asiatica grown in an experimental hydroponic condition. The results showed (i) higher accumulations of Cu and Pb in the roots of C. asiatica than those in the leaves, (ii) synergistic effects of Cu and Pb stress at higher metal-level exposures, and (iii) Cu and Pb stress triggered the increment of APX, CAT, GPX, and SOD levels in both the leaves and roots of C. asiatica. The increment of four AEA indicated that C. asiatica underwent oxidative stress caused by the production of reactive oxygen species when the plant was exposed to Cu and Pb. In order to prevent damages caused by Cu and Pb stress, the AEA system was heightened in C. asiatica, in which APX, CAT, GPX, and SOD can be used as biomarkers of Pb and Cu stress in the plant.

Despite of the introduced normative requirements, the control, the efforts made, the planned and implemented measures for environmental protection, the three large enterprises from the mining and concentrating industry contribute to the significant heavy metal pollution of forest ecosystems in the region of State Forest Enterprise Pirdop. Contamination with heavy metals leads to deterioration of soil properties, and hence to deterioration of the growth and productivity of the aboveground forest plantations. The present study aims to assess the condition of forest soils on the territory of SFE „Pirdop" by determining and interpreting a number of samples of forest floor and soil analyzed by the following parameters: pH, C% and N%, content of heavy metals Cu, Zn, Pb. Based on the obtained results the presence of acidification processes in soils was established, which creates a risk of deterioration of their forest vegetation properties and therefore worse conditions for growth and development of forest-tree vegetation. The detected pollution with heavy metals Cu, Zn, Pb in some of the studied sites is extremely high, both in the soil and in the forest floor, which indicates the need for monitoring in order to define urgent measures to reduce the risk of deterioration of the soil condition and the state of ecosystems. [ABSTRACT FROM AUTHOR]

The article is devoted to the study of the intensity accumulation of heavy metals (Pb, Cd, Zn, Cu) by vegetables in agricultural lands. Vegetable products play important role in human nutrition and requirements for quality and safety are very strict. The study was conducted on dark gray podzolic soils in the Tyvriv district of the Vinnytsia region. The fruits of the cucumber variety Dzherelo, the zucchini variety Chaklun, and the pea variety Geneva were used for the research. It is noted that the main indicators of climatic conditions during the study period were favorable for growing vegetables. It was determined that among vegetables (food peas, zucchini, cucumber) the highest content of heavy metals was observed in pea fruits. At the same time, it was found that the Cd content in pea fruits exceeded the PL (permissible level) by 1.61 times at a concentration of heavy metals in the soil below the TVL. Among heavy metals (Pb, Cd) higher migration and translocation were observed in the studied vegetables according to Cd, and among heavy metals-trace elements (Zn and Cu) - according to Cu. It was found that pea fruits were characterized by the highest coefficient of accumulation of heavy metals (Pb, Cd, Zn, Cu). The risk factor for heavy metals in the studied vegetables was lower than the threshold level of 0.1, except for Cd in peas, where this figure was 1.61 times higher. [ABSTRACT FROM AUTHOR]

Most Pb and Cd neurotoxicity studies investigate exposure to either of the toxic metals alone, while data on co-exposure are scarce. The aim of our study was to fill that gap by investigating acute combined effects of Pb and Cd on redox and essential metal status in the brain of Wistar rats. Animals were randomised in four groups of six to eight rats, which received 15 or 30 mg/kg of Cd, 150 mg/kg of Pb, or 150 mg/kg of Pb + 15 mg/kg of Cd by gavage. The fifth, control, group received distilled water only. Co-treatment with Pb and Cd induced significant increase in malondialdehyde (MDA) and thiobarbituric acid-reactive substances (TBARS) compared to control and groups receiving either metal alone. This is of special importance, as MDA presence in the brain has been implicated in many neurodegenerative disorders. The groups did not significantly differ in Zn, Cu, Mn, and Fe brain levels. Our findings highlight the importance of metal mixture studies. Neurotoxicity assessments of single chemicals do not provide a real insight into exposure to mixtures in real life. Further research should look into interactions between these metals to reveal complex molecular mechanisms of their neurotoxicity.

In the present study, the levels and probable public health risks of selected metals (Fe, Mn, Cu, Zn, Ni, Cd and Pb) in nine wheat flour samples collected from Amhara, Oromia, South region, and the Strategic Food Reserve Agency were determined using FAAS and compared with results of prior studies and critical level. The wet digestion method using 65 % HNO3 and 72 % HClO4 in 300°C for 3 h was used when preparing the sample. Validation of the optimised digestion method was assessed using the spiking method, and an acceptable percent recovery from all metals. The levels of Fe, Cu, Mn, Zn, Ni and Cd ranged between 8⋅5297 and 11⋅1535, 1⋅633 and 4⋅2346, 3⋅1875 and 8⋅5313, 2⋅3589 and 2⋅7719, 0⋅154 and 0⋅854, and 0⋅0411 and 0⋅216 mg/kg, respectively, for Ethiopian wheat flour, while the level of Fe, Cu, Mn, Zn, Ni, Cd and Pb were ranged between 8⋅0099 and 8⋅1089, 1⋅663 and 1⋅6691, 4⋅5625 and 4⋅6250, 2⋅3015 and 2⋅3072, 0⋅9423 and 1⋅1346, 0⋅1593 and 0⋅1606, and 0⋅13 and 0⋅1381 mg/kg, respectively, for imported wheat flour. However, Pb had a concentration of less than 0⋅043 mg/kg for Ethiopian wheat flour. Findings indicate that Ethiopian wheat is comparatively higher in Fe, Mn, Cu, Zn and Cd, but lower in Ni and Pb than imports. From the result of the study, it can be concluded that the level of heavy metals determined in this study was within the permissible limit, and no probable health risk because both the Hazard quotient (HQ) and the Hazard Index (HI) are found to be below 1⋅0 regarding study metals.

A fixed-bed sand column with graphene oxide (GO) layer was used to remove heavy metals (Cu(II) and Pb(II)) from an aqueous solution injected under steady flow. Due to the time constrained kinetic process of heavy metal sorption to GO, removal efficiency was affected by the injection flow rate. When injection flow rate changed from 1 to 5mLmin-1, the removal efficiency of the two metals decreased from 15.3% to 10.3% and from 26.7% to 19.0% for Cu(II) and Pb(II), respectively. Provided a fixed concentration of heavy metals in the injected flow, an increase in GO in column from 10 to 30mg resulted in an sharp increase in the removal efficiency of Pb(II) from 26.7% to 40.5%. When Cu(II) and Pb(II) were applied simultaneously, the removal efficiency of the two metals was lower than when applied by individually. GO-sand column performance was much better for the removal of Pb(II) than for Cu(II) in each corresponding treatment. When breakthrough curve (BTC) data were simulated by the convection-dispersion-reaction (CDER) model, the fittings for Cu in every treatment were better than that of Pb in corresponding treatment. Considering the small amount of GO used to enable the sand columns that resulted in a great increase in k value, compared to the GO-free sand columns, the authors propose GO as an effective adsorption media in filters and reactive barriers to remove Pb(II) from flowing water.

Pontechium maculatum, a facultative metallophyte, was collected from four ultramafic localities in Serbia and analysed in terms of micro- and macroelement accumulation. The aim of the study was to reveal trace element profiles and differences in uptake and translocation of heavy metals in populations growing under heavy metal stress. The concentrations of major and trace elements in soil samples (Ca, Mg, Fe, Mn, Ni, Pb, Cr, Zn, Cu, Co, Cd) and in plant tissues (Fe, Mn, Ni, Pb, Cr, Zn, Cu, Co, Cd) are presented. The results of our analysis indicate that P. maculatum efficiently absorbs Zn and Cr, while for most of the other elements accumulation levels fit in the range of values obtained for several other species from ultramafic localities on the Balkan Peninsula.

Heavy metal pollution is a global problem although its sources and trends differ by region and time. To data, no published research has reported heavy metal pollution in global rivers and lakes. This study reviewed past sampling data across six continents from 1970 to 2018 and analyzed the trends and sources of 10 heavy metal species in sediments from 289 rivers and 133 lakes. Collectively, river sediments showed increasing trends in Cd, Cr, Ni, Mn, and Co and decreasing trends in Hg, indicating that rivers acted as a sink for the former and a source for the latter. Lake sediments showed increasing trends in Pb, Hg, Cr, and Mn, and decreasing trends in Cd, Zn, and As, indicating that lakes acted as a sink for the former and a source for the latter. Due to difference in natural backgrounds and development stage in continents, mean metal concentrations were generally higher in Europe and North America than in Africa, Asia, and South America. Principal component analysis showed that main metal source was mining and manufacturing from the 1970s to 1990s and domestic waste discharge from the 2000s to 2010s. Metal sources in sediments differed greatly by continent, with rock weathering dominant in Africa, mining and manufacturing dominant in North America, and domestic waste discharge dominant in Asia and Europe. Global trends in sediment metal loads and pollution-control measures suggest that the implementation of rigorous standards on metal emissions, limitations on metal concentrations in manufactured products, and the pretreatment of metal-contaminated waste have been effective at controlling heavy metal pollution in rivers and lakes. Thus, these efforts should be extended globally. [ABSTRACT FROM AUTHOR]

Pb(II) leakage from batteries, dyes, construction materials, and gasoline threaten human health and environmental safety, and suitable adsorption materials are vitally important for Pb(II) removal. Bone char is an outstanding adsorbent material for water treatment, and the effectiveness in Pb(II) removing need to be verified. In this paper, the transport characteristics of Pb(II) in columns filled with a sand and bone char mixture were studied at the laboratory scale, and the influences of the initial concentration, column height, inlet flow rate, and competing ion Cu(II) on Pb(II) adsorption and transport were analyzed. The Thomas and Dose-Response models were used to predict the test results, and the mechanisms of Pb(II) adsorption on bone char were investigated. The results showed that the adsorption capacity of the bone char increased with increasing column height and decreased with increasing initial Pb(II) concentration, flow rate, and Cu(II) concentration. The maximum adsorption capacity reached 38.466 mg/g and the saturation rate was 95.8% at an initial Pb(II) concentration of 200 mg/L, inlet flow rate of 4 mL/min, and column height of 30 cm. In the competitive binary system, the higher the Cu(II) concentration was, the greater the decreases in the breakthrough and termination times, and the faster the decrease in the Pb(II) adsorption capacity of the bone char. The predicted results of the Dose-Response model agreed well with the experimental results and were significantly better than those of the Thomas model. The main mechanisms of Pb(II) adsorption on bone char include a surface complexation reaction and the decomposition-replacement-precipitation of calcium hydroxyapatite (CaHA). Based on selectivity, sensitivity, and cost analyses, it can be concluded that bone char is a potential adsorbent for Pb(II)-containing wastewater treatment. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Inorganic Analytical Chemistry / Zhongguo Wuji Fenxi Huaxue is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Metals are among the pollutants of highest concern in urban areas due to their persistence, bioavailability and toxicity. High concentrations of metals threaten aquatic ecosystem functioning and biodiversity, as well as human health. High-resolution estimates of pollutant sources are required to mitigate exposure to toxic compounds by identifying the specific locations and associated site characteristics where the deposition of metals is greatest. Mosses have been widely used as low-cost biological monitors of metal pollution for decades, because they readily accumulate pollutants over time, reflecting long term pollution levels. However, spectroscopic techniques to determine the concentration of metal pollutants in moss samples still require expensive instrumentation and involve time consuming sample preparation protocols with heavy use of reagents. Here we present protocols to perform in-situ and laboratory X-ray fluorescence (XRF) spectroscopy of epiphytic moss as rapid, low-cost, and accurate alternatives to conventional metal pollution biomonitoring. We also report on a preliminary validation of the measurements using mass fractions determined by inductively coupled plasma atomic emission spectroscopy (ICP-OES) as reference. • XRF measurements are taken from moss directly on tree trunks in less than five minutes. • Grinding and pelletizing of moss enables definitive quantitation (R2>0.90) of metals through portable XRF.

Bu araştırmada Sivas ve yöresinde bulunan 5 süt fabrikasının depo tankından temin edilen 50 adet süt örneğinde ağır metallerden kadmiyum (Cd), bakır (Cu), krom (Cr) ve kurşun (Pb) içerikleri incelenmiştir. Araştırma sonucunda süt örneklerinin Cd, Cu ve Cr içeriklerinin sırasıyla 8,896, 33,69 ve 31,81 µg/kg düzeyinde olduğu saptanmıştır. Süt örneklerin %92’inde Pb miktarının tespit edilebilir limitin altında, %8’inde ise 304,1-503,4 µg/kg olduğu belirlenmiştir.

Variation in the trace element chemistry of cortical bone microstructure is delineated for interred and non-interred human femora. This was done to investigate the range of element concentrations that might occur within single bones, specifically the original laminar bone and later osteons, and its potential for investigating chemical life histories. To do so, femora were chosen from individuals who experienced quite different ways of life over the past two millennia. The distributions of Sr, Ba, Cu, and Pb, mostly in partial (early) and complete (late) osteons, in cross-sections of proximal femora were characterized through Laser Ablation Inductively Coupled Plasma Mass Spectrometry. Absolute calibrations of these data were obtained using solution Inductively Coupled Plasma Mass Spectrometry on adjacent dissolved bulk samples. Chemical life histories were approximated by classifying bone microstructure into four categories: laminar bone and 1st, 2nd, and 3rd generation osteons. This four-part sequence, on average, charts the temporal dimension of an individual's life. Consistent with recent studies of medieval bones, Sr and Ba are thought to be mainly responsive to diet, presumably related to the consumption of mostly locally produced food, while Cu and Pb do the same for heavy metal exposure often attributable to social status or occupation. No systematic differences in these elements were found between interred and non-interred individuals. The effect of diagenesis on interpretations of life histories based on archaeological bone, therefore, are minimized by plotting element concentrations across cortical bone cross-sections. [ABSTRACT FROM AUTHOR]

Most Pb and Cd neurotoxicity studies investigate exposure to either of the toxic metals alone, while data on co-exposure are scarce. The aim of our study was to fill that gap by investigating acute combined effects of Pb and Cd on redox and essential metal status in the brain of Wistar rats. Animals were randomised in four groups of six to eight rats, which received 15 or 30 mg/kg of Cd, 150 mg/kg of Pb, or 150 mg/kg of Pb + 15 mg/kg of Cd by gavage. The fifth, control, group received distilled water only. Co-treatment with Pb and Cd induced significant increase in malondialdehyde (MDA) and thiobarbituric acid-reactive substances (TBARS) compared to control and groups receiving either metal alone. This is of special importance, as MDA presence in the brain has been implicated in many neurodegenerative disorders. The groups did not significantly differ in Zn, Cu, Mn, and Fe brain levels. Our findings highlight the importance of metal mixture studies. Neurotoxicity assessments of single chemicals do not provide a real insight into exposure to mixtures in real life. Further research should look into interactions between these metals to reveal complex molecular mechanisms of their neurotoxicity. [ABSTRACT FROM AUTHOR]

The paper presents data on the involvement of local populations of bank vole (Clethrionomys glareolus) in the biogeochemical cycles of Cu, Zn, Cd, and Pb at territories strongly chemically polluted by large nonferrous metallurgical plant in the Middle Urals (in 1990–1992) and after a significant decrease in its emissions (in 2015–2017). At maximally polluted areas (impact zone), the animal-controlled transit Cu, Cd, and Pb flows approached their background values by the end of the study period, and the Zn flow simultaneously twofold decreased compared to the background areas. At moderately polluted areas (buffer zone), no significant changes in the metal fluxed were detected for any of the elements. The specifics of the transit flows of the elements at variably polluted areas are controlled by the concentrations of these elements in the diet of the animals and by the abundance of voles. Thereby the manyfold (fifty-fold) decrease in the emissions did no result in an equivalent decrease in the concentrations of the metals in the animal rations at the polluted areas. The main reason for the changes was a structural transformation in the community of the small mammals, which led to a drastic decrease in the bank vole population in the impact zone. The simultaneous effects of the analyzed factors over the study period of time (25 years) resulted in intensification (in the background zone), retardation (impact zone), and stabilization (buffer zone) of the biogeochemical exchange of the elements. [ABSTRACT FROM AUTHOR]

Copyright of South China Fisheries Science is the property of South China Fisheries Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The adsorption characteristics of metal ions in unitary (Pb(II), Cu(II), and Cd(II)); binary (Pb(II)-Cu(II), Pb(II)-Cd(II), and Cu(II)-Cd(II)); and ternary (Pb(II)-Cu(II)-Cd(II)) systems in white pottery clay were investigated. The influence of the white pottery clay content, pH value, and ion strength on Pb(II) adsorption was analyzed, and the kinetic and isothermal equilibrium adsorption characteristics of Pb(II), Cu(II), and Cd(II) are discussed. The results showed that the adsorption reactions of white pottery clay for Pb(II), Cu(II), and Cd(II) are all rapid reactions that reach equilibrium in 180 min. The pseudo-second-order kinetic model fits the experimental results well. The Langmuir model can accurately predict the isothermal adsorption process of Pb(II), Cu(II), and Cd(II), and the monolayer maximum adsorption capacity of white pottery clay reached 159.236, 38.491, and 26.991 mg/L, respectively. Cu(II) can significantly inhibit the adsorption of Pb(II) on white pottery clay in the Pb(II)-Cu(II) binary system, and the inhibition effect is stronger at a higher Cu(II) concentration, while Cd(II) shows less of an inhibitory effect in the Pb(II)-Cd(II) binary system. The competitive adsorption effect superimposes in the Pb(II)-Cu(II)-Cd(II) ternary system, which results in a significant decrease in the capacity of white pottery clay to adsorb all three metals. Among them, the adsorption capacity of Pb(II) decreases with increasing Cu(II) and Cd(II) concentrations, whereas the adsorption of Cu(II) and Cd(II) is less affected by concentration changes of Pb(II). [ABSTRACT FROM AUTHOR]

Copyright of Journal of Henan Agricultural Sciences is the property of Editorial Board of Journal of Henan Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effect of temporal shifts in diurnal geomagnetic variation with 6- and 12-h intervals relative to the day–night cycle on the activity of digestive glycosidases (maltase and amylolytic activity) and their sensitivity to the in vitro influence of heavy metal ions (Cu2+, Zn2+, Pb2+, Cd2+) at a concentration of 25 mg/L has been studied in roach Rutilus rutilus (L.) underyearlings. Amylolytic activity (the total activity of starch-hydrolyzing enzymes: α-amylase, glucoamylase, and maltase) is determined by the modified Nelson method, maltase activity by the glucoseoxidase method with a Fotoglukoza clinical biochemistry kit. It is found that exposing embryos to both 6- and 12-h shifts in diurnal geomagnetic variation reduces the activity of maltase and its sensitivity to the effect of zinc and cadmium ions. Amylolytic activity increases only in roach underyearlings exposed to a 6-h shift in diurnal geomagnetic variation as embryos. The sensitivity of starch-hydrolyzing enzymes to the influence of copper (6- and 12-h shifts) and cadmium (12-h shift) increases. The decrease in the enzyme activity and its increased sensitivity to the inhibitory effect of heavy metals may reduce the efficiency of carbohydrate hydrolysis in roach underyearlings. The increase in the amylolytic activity can be considered as adaptation of the digestive system of the fish to a 6-h shift in diurnal geomagnetic variation relative to the day–night cycle during embryogenesis. [ABSTRACT FROM AUTHOR]

Copyright of Problems of Environmental Biotechnology is the property of National Aviation University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Donkey milk is a complex food, beneficial to the human body. It is widely used in the treatment of food allergies and in the nutrition of children suffering from various diseases. Donkey milk was analyzed to assess the level of heavy metals under the influence of lactation. Lactation has influenced the amount of heavy metals. Heavy metals were present in the highest quantities in lactation 4 and the lowest in lactation 1. The following heavy metals in donkey milk were analyzed: Cu, Pb, Fe, Zn, Na, Mg, Al and Cu. The analyzed heavy metals show the highest average values in lactation 4: Fe (1.98 ± 0.03), (Zn 2.03 ± 0.01), Na (192 ± 1.91), Mg (44.72 ± 0.71), Al (5.49 ± 0.20) and Mg (44.72 ± 0.71). [ABSTRACT FROM AUTHOR]

The objective of this work is to assess response characteristics of conventional mercury film (MFE) and (poly)indoline modified mercury film electrodes (ICMFE) in determination of Cu, Pb and Cd ions by voltammetric stripping analysis. Parameters regarding to mercury and polymer film formations (such as potential, electrochemical mode chosen for film growth, polymer and mercury film thicknesses) and supporting electrolyte type and pH in stripping analysis were thoroughly studied, and conditions providing the highest and most stable responses for the three test metal ions were determined for both electrode types. Performances of the electrodes were evaluated in terms of sensitivity and selectivity in both synthetic aqueous solutions and urine samples. Responses at ICMFE were invariably much lower compared to that obtained at plain MFE. Decomposition of urine samples by hot mineral acid gave rise to enhanced responses at both electrodes. However, ICMFE always exhibited negative selectivity toward Cd even in acid decomposed urine samples. Reliability of the concentration values calculated by the method of standard addition in complex matrices, such as urine, was discussed comprehensively on statistical basis. [ABSTRACT FROM AUTHOR]

The speciation of Cu, Pb, and Zn compounds in Haplic Chernozem under the anthropogenic impact of a power plant mainly operating on coal was studied. General tendencies in the distributions of Cu, Pb, and Zn among the compound forms were revealed using selective sequential extractions (Miller method modified by Berti and Jacobs (1996)), which is based on the nature of metals and the participation of soil components. In an uncontaminated soil occurring far from the emission source, 55–85% of total Cu, Zn, and Pb fractions are concentrated in the residual fraction characterizing the metal bond with silicates. In uncontaminated soils, the contents of Cu, Pb, and Zn in crystallized Fe compounds are largely higher than in its amorphous forms. Metals accumulate in the soil occurring near the power plant, which increases the total contents of Cu, Pb, and Zn in 1.3–2.5 times and their mobile (water-soluble, exchangeable, and carbonate-bound) compounds in 2–12 times. The largest contributions to the adsorption and retention of metals are made by silicates, as well as soil organic matter for Cu and Pb and nonsilicate Fe compounds for Zn. A significant increase in the exchangeable Zn fraction is observed in studied soils. The estimation of the degree of metal fixation in the soil was calculated Partition index of element, which reflects the degree of metal-soil bonding. It showed that the highest parameter value for the studied metals was found for the soils located at 15 km from the NPP, where the Index values approach 1; the lowest Index value is noted for contaminated soils nearby from the enterprise. Thus, sequential extraction is an effective tool to check the affinity of the soil components for Cu, Pb and Zn. Image 1 • The metals fractional distributions in soil under contamination was studied. • Soil organic matter for Cu and Pb is the main soil binding compound under contamination. • Zn content bound to amorphous and crystalline Fe was increased under contamination. [ABSTRACT FROM AUTHOR]

Purpose: Contamination of agricultural soils with potential toxic elements (PTEs) has caused serious health and environmental concern all over the world. Therefore, eco-friendly solutions for Pb and Cu immobilization were required to minimize their mobility through various types of biochar amendments in contaminated soil. Materials and methods: A greenhouse pot study was conducted to evaluate the comparative effect of rapeseed residue (RP), and rice straw (RS)-derived biochars, produced at different temperatures on Pb and Cu mobility and their accumulation in a high metal accumulating crop such as Chinese cabbage (Brassica chinensis L.). Sequential extraction, leaching toxicity, and phytoavailability techniques were used to assess Pb and Cu mobility. The impacts of various types of biochars on soil surface electronegative charge and soil enzymatic activity were also investigated in contaminated soil. Results and discussion: The sequential extraction results revealed that the application of 5% of high-temperature rice straw biochar (RS550) and rapeseed residue biochar (RP550) significantly reduced the acid-soluble fractions (active fractions) of Pb and Cu by 53.50 and 50.35% respectively. Following the addition of 5% RS550, the residual fraction (stable fractions) of Pb and Cu were increased by 36.14 and 50.94% respectively. A remarkable decrease in Pb and Cu phytoavailability and solubility was observed after the soil was treated with 5% of both RS550 and RP550 biochars. In all biochar treatments, the maximum reduction of Pb concentration in roots and shoots of the cabbage was 37.81 and 26.54%, respectively, while the concentration of Cu decreased by 50.41 and 46.25%, respectively. Incorporation of biochar into contaminated soils also improved soil urease, catalase, and acid phosphatase activities as compared to the control soil. Conclusions: Biochar application greatly enhanced the Pb and Cu immobilization, reduced phytoavailability to Chinese cabbage, and improved soil enzymes activity. The significant increment in soil surface electronegative charges and soil pH after biochar incorporation was considered one of the Pb and Cu immobilization mechanisms. Overall, application of rice straw biochar produced at 550 °C could potentially be a safe, efficient, and sustainable approach to stabilize Pb and Cu and restore soil functions in contaminated soil. [ABSTRACT FROM AUTHOR]

Abstract There is critical concern over heavy metals because they are biotoxins. The best management option is elimination or at least minimization of effluence into the environment, but in several regions, mining wastewater or acid mine drainage (AMD) effluence into natural wetlands has continued. The ability of wetlands to attenuate heavy metals in mining wastewater and AMD has led to natural wetlands being used as recipients of these effluents in many parts of the world. Ten greenhouse-based laboratory-scale constructed wetlands (GLCW) were set up at IHE-Delft Institute for Water Education to understand the mechanisms and fate of heavy metals in three Zambian wetlands in attenuation of Co, Cu, and Pb. These were operated as Free Water Surface Constructed Wetlands (FWS-CWs). The principal investigations compared how vegetated and unvegetated microcosm artificial wetlands retained controlled additions of heavy metals and the effect of drying and rewetting on that. The potential for phytoremediation using Typha angustifolia was also investigated. Typha angustifolia was planted in three vegetated and compared with one unvegetated treatment. Treatments A, B, and, the investigated, Treatment D received synthetic wastewater containing Co, Cu, and Pb, while a control, Treatment C, received tap water. Water samples were taken throughout the experiment, and sediment samples collected after the first flushing and before drying. Samples of T. angustifolia were taken before drying the wetlands. Analyses for Co, Cu, and Pb were made in the water and sediment, and in roots, stems and leaves of plant samples. The unvegetated Dutch sediments GLCWs removed more Co from wastewater (52%) than the vegetated Dutch and Zambian sediments GLCWs (13% and −4%, respectively). There was a similar removal of Cu among the GLCWs receiving wastewater (81%–87%). The removal of Pb was significantly higher in the vegetated Dutch sediment GLCWs than the unvegetated Dutch sediments GLCWs, (89% and 72%, respectively). It was concluded that a hectare of the vegetated Zambian sediments with similar design parameters of 50 mg/m2.day for Co, Cu, and Pb used in the experiment would on average retain 83 g/day of Co, and 417 g/day of both Cu and Pb. After drying, Co, Cu, and Pb washed out on the first day of rewetting. The washout after that took only a few days. How long the metals washed out of the GLCWs was in order Co > Cu > Pb. T. angustifolia could neither be classified as an accumulator nor an excluder species because the concentrations of Co, Cu, and Pb in the sediments and T. angustifolia were below phytotoxic levels mainly due to a short running period of the experiment. [ABSTRACT FROM AUTHOR]

Abstract The effects of interaction between Bacillus subtilis DBM and soil minerals on Cu(II) and Pb(II) adsorption were investigated. After combination with DBM, the Cu(II) and Pb(II) adsorption capacities of kaolinite and goethite improved compared with the application of the minerals independently. The modeling results of potentiometric titration data proved that the site concentrations of kaolinite and goethite increased by 80% and 30%, respectively after combination with DBM. However, the involvement of functional groups in the DBM/mineral combinations resulted in lower concentrations of observed sites than the theoretical values and led to the enhancement of desorption rates by NH 4 NO 3 and EDTA-Na 2. The DBM-mineral complexes might also help to prevent heavy metals from entering DBM cells to improve the survivability of DBM in heavy metal-contaminated environments. During the combination process, the extracellular proteins of DBM provided more binding sites for the minerals to absorb Cu(II) and Pb(II). In particular, an especially stable complexation site was formed between goethite and phosphodiester bonds from EPS to enhance the Pb(II) adsorption capacity. So, we can conclude that the DBM–mineral complexes could improve the Cu(II) and Pb(II) adsorption capacities of minerals and protect DBM in heavy metal-contaminated environments. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]