Soil and water contamination by potentially toxic metals (PTMs) has exerted adverse environmental impacts, which justifies studies of promising remediation alternatives. This article investigated the ...competitive sorption of cadmium (Cd), lead (Pb), and zinc (Zn) onto peat, compost, and biochar derived from the organic fraction of municipal solid waste (OFMSW), but its main innovation was the post-sorption assessment. The effects of contact time on competition between contaminants were systematically analyzed by batch experiments and the effectiveness of the sorption process was evaluated in desorption tests (H2O, HCl, NaOH, and NaCl) and sequential extraction. Kinetic data were well-fitted to pseudo-first-order (PFO) and pseudo-second-order (PSO) models and the intra-particle diffusion model revealed the existence of multiple linear regions, indicating the sorption process was controlled by a multi-step mechanism. The sorption capacities followed a biochar > compost > peat order, with biochar retaining more than 99% of Cd, Pb, and Zn in all samples. The general order of desorption percentage was peat > compost > biochar, with a below 0.60% biochar release, suggesting the importance of chemical processes. HCl solution (more acid pH) showed the highest release of previously sorbed contaminants and, therefore, can be employed for the reuse of sorbents (sorption/desorption cycles). The only exception was Pb desorption on biochar, with maximum release in NaOH solution. A negative Pearson correlation with F1 (acid-soluble/exchangeable fraction) for Cd and Zn and a positive one with the other steps were reported. Pb exhibited an opposite behavior, showing the highest sorption performances and the lowest desorption rates for all sorbents, justified by positive correlations with F4 (residual fraction) and negative ones with desorption. The findings suggest the evaluated sorbents, especially compost and biochar, can be effective materials in the simultaneous sorption of Cd, Pb, and Zn in wastewater, as well as an amendment for PTMs immobilization in contaminated soils.
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•Compost and biochar are environmentally friendly and innovative sorbents.•The order of sorption capacities was biochar > compost > peat.•Biochar showed an excellent sorption capacity and the lowest desorption rates.•Pb showed the highest sorption and the lowest desorption in multi-metal systems.•Pearson correlations were more similar for Cd and Zn and more different for Pb.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•Potentially toxic metals (PTMs) in coal mining posed a significant health risk to 0-6 years children.•Fe/Mn hydroxide and carbonate-bound fractionations of PTMs determine the ...gastrointestinal and lung bioaccessibility.•BLLs across age-and gender-differences reveal the effect of coal mining on 0-6 years children’s health.•The findings contribute the strategy for coal mining management and environment lead reduction.
Coal is a primary energy source in the world. Potentially toxic metals (PTMs) emission from coal mining and combustion are posing a serious public health concern. In order to quantify and evaluate the effect of PTMs on children’s health, the concentrations of 12 PTMs (As, Co, Cr, Cu, Mn, Ni, Pb, Sr, Zn, Ca, Fe, and Mg) bound in urban soil and street dust are determined and blood lead levels of these PTMs in 229 children (0–6 years old) are collected from the coal mining city of Yulin, China. In vitro pulmonary bioaccessibilities of PTMs are evaluated by artificial lysosomal fluid and Gamble’s solution, and gastrointestinal bioaccessibilities by the unified BAGRE method (UBM); correlations between chemical speciation of PTMs and their bioaccessibility are examined, and children’s (0–6 years old) health risks are systematically studied. Similar distribution levels of PTMs are found in soils and dusts, with the most polluted metals being Co, Sr, Ca and Pb. All PTMs (except Cr, Fe) are from the considerable artificial lysosomal fluid extraction both in soil and dust, while Ca and Co are favorably extracted in gastro and intestinal phases than others. Significant correlations are observed between the bioaccessibilities (lung and gastrointestinal) and Fe/Mn hydroxide-bound and carbonate-bound phases, which are key factors influencing and determining PTMs’ bioaccessibility. Blood lead levels for children (0–6 years old) are 27.47 (21.65, 33.30) for 0–1 year olds, 32.29 (26.39, 38.19) for 1–2 year olds, 36.99 (28.16, 45.81) for 2–3 year olds, 30.79 (22.56, 39.01) for 3–4 year olds, 27.12 (17.31, 36.93) for 4–5 year olds, 34.59 (24.22, 44.97) for 5–6 year olds and 37.83 (24.15, 51.51) μg/L for 6–7 year olds, respectively, with 3.93%, 3.49%, 4.80%, 2.62%, 1.31%, 1.75% and 1.31% exceeding 50 μg/L, respectively. This indicates that the blood lead levels elevate for 1–2 year and 5–6 year old groups, which should be paid more attention. Although the non-carcinogenic and carcinogenic risks of most PTMs are under the acceptable level, the higher carcinogenic risk of Ni and non-carcinogenic risk of Pb should be monitored continuously. We suggest that further actions will be taken to reduce PTMs exposure for children through sustainable clean and ecological energy technology for coal mining, especially for those infants of 1–2 years old.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Sea level rise and extreme weather conditions caused by climatic changes enhance the frequency and length of submersion events in coastal soils, causing deposited airborne dusts to get in contact ...with marine salts.
The behaviour of Cd, Zn and Pb from pedogenetic minerals and from dusts from mining and smelting activities, added to two soils under different agricultural management (arable and grassland) was examined after soil flooding for 1, 7 and 30 days with waters of increasing salinities (0, 4.37, 8.75, 17.25 and 34.5 g L−1). A rain water event following 1 d flooding released an extra amount of metals. Concentration of potentially toxic elements (PTE), pH, dissolved inorganic and organic C were measured in solutions collected by gravity from soil columns. Speciation distribution of leached metals and oversaturation parameters were calculated by Visual Minteq 3.0 and showed that complexation by chloride ions for Cd and fulvic acids for Pb were the drivers of solubilisation, while Zn interacted with both.
Results showed that marine salts enhance up to 300 times leaching of Cd, and several times that of Zn and Pb from contaminated soils and that airborne toxic elements are much more mobilized than pedogenic ones. Smelter exhaust metals, particularly Pb, were made more mobile than those in mine tailings (up to 55 against 0.7 ng μg-1 Pb). Soil management strongly also influence mobilization by saline water: much lower amounts were leached from the grassland soil. Soil organic matter quality (DOC and humification) affects the extent of mobilization. The length of the flooding period did not result in coherent time trend patterns for the three metals, probably because of the multiple changes in solution parameters, but leached metals were always highly linearly correlated negatively with pH and positively with DOC.
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•Sea or brackish water flooding increases solubility of PTE from airborne dusts.•Airborne PTE are much more mobilized than geogenic soil PTE.•Contamination source has strong influence on the amount of PTE dissolved.•Airborne PTE are made more soluble in arable than grassland soils.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Contamination by potentially toxic metals and metalloids (PTMs) has become a significant health and environmental issue worldwide. Sorption has emerged as one of the most prominent strategies for ...remediating both soil and water contamination. New sorbents are being developed to provide economically viable and environmentally sound alternatives, in alignment with the principles of the Sustainable Development Goals. This research aimed to assess the potential effects on human health and environmental toxicity following the sorption of cadmium (Cd), lead (Pb), and zinc (Zn) using peat, compost, and biochar as sorbents. The peat was collected in Brazil, a country with a tropical climate, while the compost and biochar were produced from the organic fraction of municipal solid waste (OFMSW). In terms of bioaccessibility, the results showed the following order: compost < biochar < peat for Pb, and compost < peat < biochar for Cd and Zn. There was a significant growth inhibition for Eruca sativa and Zea mays exposed to increasing concentrations of PTMs treated with peat and compost. The presence of contaminants played a decisive role on immobilization of neonates of Ceriodaphnia silvestrii after treatments with compost and, especially, peat. However, the biochar addition rate caused a significant influence on the outcomes of ecotoxicity across all tested species. Although the samples treated with biochar exhibited lower residual concentrations of PTMs than those treated with compost and peat, the inherent toxicity of biochar might be attributed to the material itself. The exposure to residual PTM concentrations post-desorption caused ecotoxic effects on tested species, emphasizing the need to assess PTM desorption potential. Peat, compost, and biochar are promising alternatives for the sorption of PTMs, but the addition rates must be properly adjusted to avoid the occurrence of undesirable ecotoxicological effects. This research offers valuable insights for sustainable environmental management and protection by thoroughly investigating the impacts of different sorbents and contaminants on aquatic and terrestrial ecosystems.
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•Pb had lowest bioaccessibility among tested metals when pre-sorbed onto the compost.•The sensitivity order was established as: root length > shoot length > germination.•Eruca sativa displayed higher phytotoxicity compared to Zea mays.•Biochar revealed inherent aquatic ecotoxicity in Ceriodaphnia silvestrii.•The toxicity of peat and compost samples originated from the presence of PTMs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Tree-herb intercropping is a prospective approach for the ecological remediation of soil contaminated with potentially toxic metals (PTMs). In this study, the facilitation and microbial community ...response of woody plant Morus alba L. intercropped with Cd/Zn hyperaccumulator Sedum alfredii H. and pioneer plant Arundo donax L. were carried out in the PTM-contaminated soil. The results indicated that the intercropping system can improve M. alba L. growth, as well as increase its PTMs uptake. The dried biomass of M. alba L. in the intercropping system was increased observably (p < 0.05) by 55.1%. Meanwhile, the contents of chlorophyll in M. alba L. leaves, PTMs contents in M. alba L. roots, and the relative abundance of Rhizobiaceae, Singulisphaera, Isosphaeraceae, and Arthrobacter in the M. alba L. rhizosphere were also notably (p < 0.05) enhanced. Meanwhile, the interactions of microorganisms in the intercropped plants rhizosphere might contribute to improving the biological quality of the contaminated soil. Soil sucrase and acid phosphatase activities in the intercropping system were significantly (p < 0.05) increased by 97.03% and 34.91% relative to the control. Furthermore, in the intercropping system, 93.61%, 61.30%, and 79.18% of Cd, Pb, and Zn were extracted by S. alfredii H., 72.16% of Cu was extracted by A. donax L., and 46.38% of Mn was extracted by M. alba L., which indicated that the extraction amounts of PTMs among the intercropped plants were relatively compensated. The results suggested that the tree-herb intercropping might increase the coexistence of plants and facilitate the adaptability for ecological remediation of PTM-contaminated soils.
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•Growth and photosynthesis of M. alba L. was improved by the intercropping.•Uptake of PTMs in M. alba L. roots was significantly enhanced by the intercropping.•Overall PTMs accumulation amounts were relatively complemented by the intercropped plants.•The intercropping system can enhance the interactions of microorganisms.•The change of microbial community might facilitate the coexistence of intercropped plants.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Metal pollution of agricultural soils is currently an issue of major concern in China and many soils require remediation. Photovoltaic (PV) power generation is a useful source of renewable energy but ...solar power plants often require large areas of land. Combining PV power generation with phytoextraction on contaminated arable land is therefore a novel and potential option if these processes can work effectively together. A three-year-long continuous field study was conducted to test the feasibility of phytoextraction using a metal hyperaccumulator species growing under arrays of PV panels. Meteorological data were collected and the growth and cadmium (Cd) and zinc (Zn) uptake of the Cd/Zn hyperaccumulator Sedum plumbizincicola were determined. Shading by the PV panels reduced the annual solar irradiance by 58.4% but this showed no inhibitory effect on plant growth or metal uptake by S. plumbizincicola. Phytoextraction under the PV panels gave high removal efficiencies of Cd and Zn and the hyperaccumulator took up Cd and Zn at rates of 3.40 and 96.2 kg ha−1, respectively, for three seasons. It is concluded that soil phytoextraction and PV electricity generation can be combined to realize soil remediation and energy production.
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•Combined phytoextraction with solar power generation is an emerging land-use type.•Cd/Zn hyperaccumulator Sedum plumbizincicola grew well under photovoltaic panels.•Shading by the panels did not inhibit the growth of the hyperaccumulator.•Phytoextraction of polluted soil under PV panels gave high Cd removal efficiencies.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Soil pollution in agricultural lands poses a serious threat to food safety, and suggests the need for consolidated methods providing advisory indications for soil management and crop production. In ...this work, the three-step extraction procedure developed by the EU Measurement and Testing Programme and two soil-to-plant transfer factors (relative to total and bioavailable concentration of elements in soil) were applied on polluted agricultural soils from southern Italy to obtain information on the retention mechanisms of metals in soils and on their level of translocation to edible vegetables. The study was carried out in the Sarno river plain of Campania, an area affected by severe environmental degradation potentially impacting the health of those consuming locally produced vegetables. Soil samples were collected in 36 locations along the two main rivers flowing into the plain. In 11 sites, lettuce plants were collected at the normal stage of consumption. According to Italian environmental law governing residential soils, and on the basis of soil background reference values for the study area, we found diffuse pollution by Be, Sn and Tl, of geogenic origin, Cr and Cu from anthropogenic sources such as tanneries and intensive agriculture, and more limited pollution by Pb, Zn and V. It was found that metals polluting soils as a result of human activities were mainly associated to residual, oxidizable and reducible phases, relatively immobile and only potentially bioavailable to plants. By contrast, the essential elements Zn and Cu showed a tendency to become more readily mobile and bioavailable as their total content in soil increased and were more easily transported to the edible parts of lettuce than other pollutants. According to our results, current soil pollution in the studied area does not affect the proportion of metals taken up by lettuce plants and there is a limited health risk incurred.
•Soil pollution in an intensively farmed area of southern Italy was investigated•Soil background reference values discriminated geogenic from anthropogenic pollution•Metal bioavailability in soil was assessed by sequential extractions•Transfer factors for available metal content accurately described bioaccumulation•Essential elements Cu and Zn were more easily transported to lettuce edible parts than other pollutants
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Urban and suburban road dust samples were collected in the most populated city of China, Shanghai. Size fractions of dust particles were analyzed; metal levels of the dust were also measured. Human ...exposure to individual toxic metals through road dust was assessed for both children and adults. The results showed that dust particles from urban and suburban road were presented similar size distribution pattern, with most particles in the range of 100–400
μm. Urban road dust consisted of higher proportions of inhalable, thoracic and respirable particles with increased risk of adverse effects to human. In general, mean grain sizes of urban road dust were smaller than suburban dust. Total organic carbon contents and levels of Pb, Cd, Cu, Zn, Ni, Cr in urban dust were higher than those of suburban dust. But the concentrations of As and Hg from suburban dust were higher, indicting a different main source. The exposure pathway which resulted in the highest level of risk for human exposed to road dust was ingestion of this material, which was followed by dermal contact. Except for some locations, risk values of both cancer and non-cancer obtained in this study were in the receivable range on the whole. Children had greater health risks than adults. The overall risks of non-cancer in urban area were higher than those in suburban area, but the values of cancer in the two areas were comparable. As for the aggregate noncarcinogenic risk, Pb was of most concern regarding the potential occurrence of health impacts. Of the three carcinogenic metals As, Cr and Cd, the only mean risk higher than 10
−6 was Cr, accounting for a great percentage (95%) of the overall risk of cancer. Hence, potentially adverse health effects arising from Pb and Cr in road dust should arouse wide concern.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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•Potentially toxic metals detected in drinking groundwater resources.•More than 99% and 23.46% of the study area polluted by As and Pb.•High non-carcinogenic and cancer risk estimated ...for As in probabilistic approach.•Pollutant concentration was the most sensitive factor for health risk assessment.
In this study, the concentration and spatial distribution of potentially toxic metals (PTMs), including arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), copper (Cu), iron (Fe), manganese (Mn), and magnesium (Mg) in 23 wells and drinking groundwater distribution networks of Rafsanjan, located in southeast Iran were evaluated. Moreover, the assessment of carcinogenic and non-carcinogenic risks was estimated by Monte Carlo simulation (MCS). The results showed that the concentrations of As and Pb in more than 99% and 23.46% of the study area, respectively, were higher than the maximum concentration level (10 µg/L). The mean concentration of other metals, including Cd, Cr, Cu, Fe, Mg, and Mn in all drinking water resources was within the WHO standard level. The mean hazard quotient (HQ) for As in the age group of children was 9.246 and adults 2.972, indicating high non-carcinogenic risk of As in the study area. The lifetime cancer risk (LTCR) of As was 1.36E−3 for adults and 1.52E−2 for children, indicating high non-carcinogenic risk of As. The level of HQ and LTCR for Pb in both age groups was in the acceptable range. The results of sensitivity analysis showed that the most effective variables were pollutant concentration and body weight (BW), respectively. Finally, it can be concluded that exposure to PTMs, especially As through drinking water in the study area can have significant effects on people’s health living in the area; therefore, it is necessary to treat and remove As from groundwater resources before drinking or using for domestic purpose.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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