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Herein, we demonstrate a scalable method for fabricating monodisperse sulphonated polystyrene (SPS) microspheres with abundant sulphonic acid groups and excellent heavy metal removal ability. A comprehensive characterization through SEM, EDS, FT-IR, TG, XRD and XPS confirmed the formation of the SPS microspheres. Take advantage of the abundant sulphonic acid groups on the surface of microspheres, as well as the superior monodisperse properties, adsorption ability of SPS microspheres both in quantity and speed have been enhanced. The adsorption equilibrium obeyed the Langmuir isotherm model with the theoretical maximum capacities of 49.16, 15.38 and 13.89 mg·g−1 for Pb2+, Zn2+ and Cu2+, respectively (30°C, pH = 3.5). Besides, the adsorption equilibriums of Pb2+ onto SPS microspheres can be achieved within only 1 min and the adsorption kinetics can be fitted by a pseudo-second-order kinetics model. More importantly, because of the micron structure of the SPS microspheres, it could overcome the excessive hydrophilia brought by rich sulphonic acid groups and thereby easily separated, which maintain a good recyclable capacity after five regeneration cycles. With the excellent adsorption ability and reusability, SPS microspheres can efficiently handle the polluted water in a convenience and rapid process, which satisfies the sustainable pollution treatment in heavy metals elimination. [ABSTRACT FROM AUTHOR]

Rural waste accumulation leads to heavy metal soil pollution, impacting microbial communities. However, knowledge gaps exist regarding the distribution and occurrence patterns of bacterial communities in multi-metal contaminated soil profiles. In this study, high-throughput 16 S rRNA gene sequencing technology was used to explore the response of soil bacterial communities to various heavy metal pollution in rural simple waste dumps in karst areas of Southwest China. The study selected three habitats in the center, edge, and uncontaminated areas of the waste dump to evaluate the main factors driving the change in bacterial community composition. Pollution indices reveal severe contamination across all elements, except for moderately polluted lead (Pb); contamination severity ranks as follows: Mn > Cd > Zn > Cr > Sb > V > Cu > As > Pb. Proteobacteria, Actinobacteria, Chloroflexi , and Acidobacteriota predominate, collectively constituting over 60% of the relative abundance. Analysis of Chao and Shannon indices demonstrated that the waste dump center boasted the greatest bacterial richness and diversity. Correlation data indicated a predominant synergistic interaction among the landfill's bacterial community, with a higher number of positive associations (76.4%) compared to negative ones (26.3%). Network complexity was minimal at the dump's edge. RDA analysis showed that Pb(explained:46%) and Mn(explained:21%) were the key factors causing the difference in bacterial community composition in the edge area of the waste dump, and AK(explained:42.1%) and Cd(explained:35.2%) were the key factors in the center of the waste dump. This study provides important information for understanding the distribution patterns, co-occurrence networks, and environmental response mechanisms of bacterial communities in landfill soils under heavy metal stress, which helps guide the formulation of rural waste treatment and soil remediation strategies. [Display omitted] • Rural simple garbage stacking sites can cause heavy metal pollution in soil. • The bacterial co-occurrence network in the center of L waste dump is the most complex. • Mn, Zn and Cu are the key factors to decrease microbial network complexity • The interaction between bacterial community and heavy metals、soil properties was clarified. • The interaction between microorganisms, metals and soil properties was elucidated. [ABSTRACT FROM AUTHOR]

Chemical fractions of heavy metals (Mo, Ni, Cu, Zn, Fe, Mn, Pb, Cd, and Cr) and compositions of bacteria and fungi in surface sediments from the Mo-Ni polymetallic mine area were analyzed. The results indicated that the mean concentrations of Mo, Ni, Cu, Zn, and Cd were higher than their background values. The mean percentage of Cr in residual fraction was much higher than that of other heavy metals. Mo, Cu, Zn, Fe, and Pb were mainly associated with oxidizable fraction. The dominant proportions of Mn and Cd were found in exchangeable fraction with mean percentages of 93.46% and 54.50%, respectively. According to RAC classification and potential ecological risk index (PERI), the Cd with high bioavailability had a very high environmental risk. The MisSeq sequencing results of bacteria and fungi revealed that microbial communities discrepantly respond to different sampling sites. The most abundant phylum of bacteria and fungi were Proteobacteria and Ascomycota, respectively. The bioavailable heavy metals including Mo-B, Pb-B, and Cd-B were recognized to have important influences on both dominant bacterial and fungal communities. The present study manifested that the bioavailability of heavy metal is very important to assess the potential environmental risk and plays a key role in shaping microbial structure. [ABSTRACT FROM AUTHOR]

Two wetland plant-sediment microbial fuel cell systems (PSM1 and PSM2) and one wetland sediment microbial fuel cell system (SM) were constructed to investigate their electricity production performance and the simultaneous migration and transformation of arsenic and heavy metals in sediment and overlying water, arsenic and heavy metals uptake by plants. The bioelectricity generation was monitored for 175 days, and sediment samples were collected at three time points (64, 125 and 200 days) for the analysis. The results showed that plants improved the efficiency of the electricity production by the fuel cell system. The average output voltage was: PSM1 (0.32 V) > PSM2 (0.28 V) > SM (0.24 V)(P ≤ 0.05).The electricity production of the electrodes and the introduction of plants affected the mobility and transformation of As, Zn and Cd in the sediment, which contributed to their stability in the sediment and reduced the release of these metals into the overlying water column. The bioelectricity production process affected the bioavailability of arsenic and heavy metals in the sediment and attenuated metal uptake by plants, which indicated the potential for remediation of arsenic and heavy metals pollution in sediment. [ABSTRACT FROM AUTHOR]

The speciation of metals in surface sediments, as well as metal concentrations in muscle and liver of sharpbelly Hemiculter leucisculus from a stream near the Mo–Ni polymetallic mines in Maoshi town were investigated. The results indicated that metal concentrations were generally highest in the most upstream sampling location that is closest to the former mine operation. The total concentrations of Mn in sediments were higher than other metals. The Cr was mainly associated with residual fraction, while the order of bioavailability of metals (sum of the concentrations of exchangeable, reducible, and oxidizable fractions) was as follows: Cd (89.95%) > Mn (82.32%) > Ni (45.58%) > Mo (29.39%) > Hg (29.23%) > As (22.60%) > Pb (17.38%) > Cr (6.21%). The Cd concentration in muscle of H. leucisculus exceeded the permissible limit which indicated that the fish from this area are not safe for human consumption. The potential ecological risks of Cd cannot be ignored in this study area. [ABSTRACT FROM AUTHOR]

In this study, selected heavy metals (Hg, As, Cd, Pb, Cr, Cu and Zn) in the lake water and sediments from the Caohai wetland, which is a valuable state reserve for migrant birds in China, were investigated to assess the spatial distribution, sources, bioavailability and ecological risks. The results suggested that most of the higher concentrations were found in the eastern region of the lakeshore. The concentration factor (CF) revealed that Hg, Cd and Zn were present from moderate risk levels to considerable risk levels in this study; thus, based on the high pollution load index (PLI) values, the Caohai wetland can be considered polluted. According to the associated effects-range classification, Cd may present substantial environmental hazards. An investigation of the chemical speciation suggested that Cd and Zn were unstable across most of the sites, which implied a higher risk of quick desorption and release. Principal component analysis (PCA) indicated that the heavy metal contamination originated from both natural and anthropogenic sources. [ABSTRACT FROM AUTHOR]

As the largest tributary flowing into Chaohu Lake, China, the Hangbu–Fengle River (HFR) has an important impact on the aquatic environment security of the lake. However, existing information on the potential risks of heavy metals (HMs) in HFR sediments was insufficient due to the lack of bioavailability data on HMs. Hence, geochemical fractionation, bioavailability, and potential risk of five HMs (Cr, Cu, Zn, Cd, and Pb) in HFR sediments were investigated by the combined use of the diffusive gradient in thin-films (DGT), sequential extraction (BCR), as well as the physiologically based extraction test (PBET). The average contents of Cd and Zn in the HFR Basin were more than the background values in the sediments of Chaohu Lake. A large percentage of BCR-extracted exchangeable fraction was found in Cd (8.69%), Zn (8.12%), and Cu (8.05%), suggesting higher bioavailability. The PBET-extracted fractions of five HMs were all almost closely positively correlated with their BCR-extracted forms. The pH was an important factor affecting the bioavailability of HMs. The average DGT-measured contents of Zn, Cd, Cr, Cu, and Pb were 28.07, 7.7, 3.69, 2.26, 0.5 μg/L, respectively. Only DGT-measured Cd significantly negatively correlated with Eh, indicating that Cd also had a high release risk under reducing conditions, similar to the risk assessment results. Our results could provide a reference for evaluating the potential bioavailabilities and ecological hazards of HMs in similar study areas. [Display omitted] • Zn and Cd in sediments were all present at relatively high levels. • BCR, in vitro PBET and DGT were used to assess metal bioavailability in sediments. • pH is the important factor influencing the metal bioavailability in sediments. • Cd has a potential risk of being released from sediments in the study area. Capsule: The study helps to better understand for effectively evaluating the bioavailability and potential hazards of metal elements in river sediments. [ABSTRACT FROM AUTHOR]

In recent years, with the expansion of the Weining county in the northeast of Caohai wetland, the construction of a new port in the north, and the large-scale development of cultivated land in the east, land use patterns in lakeshore areas have changed. These changes have affected the state of lake shores water bodies in complex ways, resulting in varying degrees of local water pollution. To explore the distribution and transformation characteristics of water chemistry and heavy metals in different areas of a water body under the influence of different land uses, especially the interactions between water chemical factors and heavy metals in different areas of a water body, this study used Circos diagrams, originally used in biological genetic analysis, to visualize these interactions. This is the first time that the Circos diagram has been applied to the analysis of environmental interactions. The results showed that there are significant differences in the distribution of water chemical factors and heavy metals in different areas of the Caohai wetland. In particular, Cd is affected by anthropogenic sources. The Cd content is higher in the NCL and UL areas, which are at greater risk from pollution. The factors controlling heavy metal levels in water bodies were different in the different regions. The NCL region was mainly affected by construction excavation ore, UL was mainly affected by man-made industrial inputs, CL was mainly affected by pesticide and fertilizer inputs, and ML and FL were mainly affected by Eh and DO. The PCA results showed that the sources of heavy metals in different types of water bodies in the lakeshore zone were both natural and anthropogenic. Therefore, controlling pollutants, reducing environmental pollution inputs to the lakeshore zone, and strengthening supervision and management near wetlands may be of great significance for handling heavy metal pollution. Image 1 • Hydrochemistry and metals distribution in different regions is obviously different. • Lakeshore land use patterns has a significant impact on nearby water quality. • The factors controlling heavy metal levels were different in the different regions. • Increasing the input of Ca2+ may help control the concentration of Cd in the water. [ABSTRACT FROM AUTHOR]

The agricultural land-atmospheric dustfall-plant system around the mining area is at high risks of heavy metal pollution caused by mining-smelting activities. In this study, 118 samples (including rhizospheric soils, background soils, soil-forming parent rocks, crops, vegetables, medicinal plants and atmospheric dustfall) were collected nearby Tongling Cu-Fe-Au mining area, Eastern China. We studied the concentrations, migration, sources, and health risks through consumption of two main crops (corn and rice), six kinds of vegetables, and medicinal plants (Fengdan, Paeonia ostii) for six metal elements (Cu, Zn, Cr, Cd, Pb and Hg). Results revealed Cr and Cd in soils, and Cd, Cr, Pb, Cu and Zn in dustfall showed a relatively high contamination degree. The mean contents of Cr and Pb in corn kernels, as well as Cd, Cr and Pb in rice grains and all vegetables, and Cr in Fengdan cortex moutan exceeded the corresponding food safety limits in China. The transfer capability of Cr in corn kernels and rice grains, Pb in edible vegetables, and Cd in cortex moutan were the strongest, respectively. Health risk assessment results showed Cr had the greatest non-carcinogenic risk, followed by Pb and Cd. The results of pearson's correlation analysis (CA), hierarchical cluster analysis (HCA), and principal component analysis (PCA) indicated Zn-Cr, Pb and Cd-Cu-Hg in the plants might derive from different geochemical end-members. Source apportionment based on lead isotope showed that mining-smelting activities were the major source of Pb in atmospheric dustfall and agricultural soils, with the average contribution rates of 66% and 50%, respectively. Vehicle emissions from diesel fuels (50%–68%) and mining-smelting activities (16%–25%) contributed mainly to Pb accumulation in plants. Hence, our study suggested the accumulations of Pb in plants might be mainly from the direct foliar uptake of atmospheric Pb related to vehicle emissions and mining-smelting activities. Image 1 • Cr and Cd in soils and dustfall were all present at relatively high levels. • Cr, Cd, and Pb have potential health risks via consumption of edible plants. • Sources of Cr and Cd in soil-dustfall-plant system are different. • Diesel vehicle emission was the dominant Pb source in plants. The research expands the application of lead isotope in tracing the sources of heavy metals in the more complex soil-dustfall-plant system for the mine environment. [ABSTRACT FROM AUTHOR]

Environment-friendly and cost-effective disposal and reutilization of sludge wastes are essential during the wastewater treatment process. Converting sludge wastes into ceramsite by sintering treatment is a promising strategy for sludge treatment. This paper summarizes existing processes and technologies for regenerating ceramsite from sludge wastes. The synthesis process including raw material pretreatment, sludge characteristics analysis, batching, mixing and molding, drying and preheating, sintering and cooling is discussed. Then, the effects of additives, sintering temperature and time, and sludge content on the preparation and properties of sludge-based ceramsite are summarized. Integrating mechanistic insights and different physicochemical properties highlighted the understanding of the different applications (environmental remediation and architecture ingredients) of sludge-based ceramsite. High-temperature sintering sludge-based ceramsite exhibited excellent performance for the removal of contaminants due to the high porosity, large surface area, and good biocompatibility. Besides, the sludge-based ceramsite could also be used as concrete aggregate and asphalt mixtures due to its high strength, thermal insulation, and seismic resistance. Finally, the challenges and proposals for sludge-based ceramsite are proposed. This paper can provide a theoretical basis and guidance for the preparation and application of sludge-based ceramsite. [Display omitted] • Sludge-derived ceramsite can be used as support material for biofilters. • Sludge-derived ceramsite can be applied as medium filler for constructed wetland. • Sludge-derived ceramsite as adsorbents can effectively remove heavy metals. • Sludge-derived ceramsite has three main roles as a bulking agent in composting. • Sludge-derived ceramsite can also be utilized in concrete and asphalt mixtures. [ABSTRACT FROM AUTHOR]

The ability of Metal-organic frameworks (MOFs) material Fe-MIL-88NH 2 to adsorb heavy metal Pb2+ from wastewater was studied in this paper. The influences of the contact time, initial Pb2+ concentration, adsorbent dosage and pH of solution on the adsorption performance of Fe-MIL-88NH 2 were investigated. The adsorption behavior of Pb2+ on Fe-MIL-88NH 2 was discussed by using the isotherm model and adsorption kinetic model. The Fe-MIL-88NH 2 showed good adsoption capacity for Pb2+. The adsoption process of Pb2+ on Fe-MIL-88NH 2 was better described by Freundlich isothermal and pseudo-second-order kinetic model. The Fe-MIL-88NH 2 showed excellent recycling capability in the cyclic adsorption process. The results indicated that Fe-MIL-88NH 2 has a good application prospect in the removal of Pb2+ from wastewater. The adsorption process of Pb2+ on Fe-MIL-88NH 2 can better described by the pseudo-second-order kinetic model than other model. The adsorption process is dominated by chemical adsorption. [Display omitted] • Fe-MIL-88-NH 2 is a promising adsorbent for removing of heavy metal ion Pb2+ ​from wastewater. • The adsorption behavior of Pb2+ ​on Fe-MIL-88NH 2 ​is based on non-uniform pores or surfaces as the main adsorption sites. • The adsorption of Pb2+ on Fe-MIL-88NH 2 is dominated by chemical adsorption. • The adsorption capacity of Pb2+ remains above 89.5% of the original adsorption capacity after 4 times of regeneration of Fe-MIL-88-NH 2. [ABSTRACT FROM AUTHOR]