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Retention of toxic metals/metalloids like arsenic via mineral-water interaction plays a crucial role in the environmental behavior of pollutants. However, the influence of mineral crystallinity on the retention of toxic elements, the evolution of liquid composition, and the interaction mechanism are poorly understood. This study investigated the interaction between As(V) and calcium phosphate (CaP) under oxic conditions with varying crystallinities, particularly amorphous CaP (ACP), across varying As(V) concentrations and pH conditions. Results revealed that the amorphous phase substantially influenced As(V) fate, with the As(V) retention potential of ACP and poorly crystalline hydroxylapatite (HAP) being 13.65 and 12.61 times higher than highly crystalline HAP, respectively. As(V) retention involves the dissolution of ACP and the recrystallization of As(V)-substituted HAP, correlated with three distinct ACP transformation stages during recrystallization. The lower pH (7.5) facilitated ACP dissolution, and the elevated Ca 2+ concentration enhanced the volume of CaP recrystallization. Conversely, higher pH levels (8.0, 8.5, and 9.0) promoted a higher degree of recrystallization, evidenced by reduced residual Ca 2+ levels after 48 hrs (post-crystallization stage). Meanwhile, As-bearing CaP forms with greater competition between PO 4 3- and AsO 4 3- at higher initial As(V) concentrations than lower ones. Additionally, lattice distortion, increases in species of surface bond groups, and reduced crystallinity were observed in the As(V)-bearing CaP product. Overall, this study underscores the pivotal role of ACP and its poorly crystalline counterparts in arsenic retention through the dissolution-recrystallization mechanism., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The remediation of heavy metal-contaminated soils necessitated a holistic approach that encompassed water and fertilizer conservation alongside soil property restoration. This study introduced the synthesis of (poly)acrylamide-layered double hydroxide gel spheres (PAM-LDH beads), which were designed to simultaneously immobilize heavy metals, control the release of fertilizers, and enhance soil water retention. Laboratory soil experiments under diverse conditions highlighted the superior performance of PAM-LDH beads in the immobilization of hexavalent chromium (Cr(VI)). The layered double hydroxide (LDH) component was identified as the key player in Cr(VI) immobilization, with anion exchange being the predominant mechanism. Notably, the encapsulated urea within the beads was released independently of environmental influences, governed by a concentration gradient across the beads surface. This release process was characterized by an initial phase of absorptive swelling followed by a diffusive phase. The impact on plant growth was assessed, revealing that PAM-LDH beads significantly curtailed Cr(VI) accumulation and alleviated its phytotoxic effects. Changes in the carbon (C) and nitrogen (N) content of the plants suggested that the urea encapsulated within the beads served as a nutrient source, contributing to soil fertility. Moreover, the water-holding capacity and soil-water characteristic curves of PAM-LDH beads suggested that these superabsorbent beads could delay soil water evaporation. The observed shifts in microbial community structure provided evidence for the enhancement of soil carbon and nitrogen cycles, indicative of improved soil properties., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Algae-derived organic matter (ADOM) is a key source of chromophoric dissolved organic matter (CDOM) in natural waters. When exposed to solar irradiation, ADOM undergoes gradual degradation and transformation. The escalating presence of microplastics (MPs) can act as a novel type of environmental photosensitizer, however its impacts on ADOM photodegradation remains largely unexplored. Thus, in this study, ADOM were extracted from four common algal species (Microcystis aeruginosa, Synechococcus sp., Chlorella pyrenoidosa and Scenedesmus obliquus) and exposed to UV irradiation with or without polystyrene (PS) MPs, namely ADOM+PS groups and ADOM groups, respectively. The results indicated that a more rapid degradation of amino acid-like substances (∼38 % vs. ∼22 %) and more ammonia products (1.86 vs. 1.21 mg L -1 ) were observed in the ADOM+PS groups compared to the ADOM groups after a five-day exposure. This enhanced photodegradation might be attributed to the production of environmentally persistent free radicals and reactive species during the photoaging of PS. Furthermore, PS-derived high electron transfer belt activity of ADOM led to the production of highly aromatic and humified products. These humic-like products could potentially accelerate the degradation of amino acid-like compounds by exciting the generation of excited triplet CDOM. This study underscores the role of MPs as environmental photosensitizers in promoting ADOM degradation and ammonia generation, providing insights on the transformation of ADOM mediated by emerging pollutants and its impact on aquatic carbon and nitrogen cycles., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

A precious metal catalyst with loaded Pt single atoms was prepared and used for the complete oxidation of C 3 H 6 O. Detailed results show that the T 100 of the 1.5Pt SA/γ-Al 2 O 3 catalyst in the oxidation process of acetone is 250 °C, the TOF of Pt is 1.09 × 10 -2 s -1 , and the catalyst exhibits good stability. Characterization reveals that the high dispersion of Pt single atoms and strong interaction with the carrier improve the redox properties of the catalyst, enhancing the adsorption and dissociation capability of gaseous oxygen. DFT calculations show that after the introduction of Pt, the oxygen vacancy formation energy on the catalyst surface is reduced to 1.2 eV, and PDOS calculations prove that electrons on Pt atoms can be quickly transferred to O atoms, increasing the number of electrons on the σ p * bond and promoting the escape of lattice oxygen. In addition, in situ DRIFTS and adsorption experiments indicate that the C 3 H 6 O oxidation process follows the Mars-van Krevelen reaction mechanism, and CH 2 =C(CH 3 )=O (ads) , O* (O 2 - ), formate, acetate, and carbonate are considered as the main intermediate species and/or transients in the reaction process. Particularly, the activation rate of O 2 and the cleavage of the -C-C- bond are the main rate-determining steps in the oxidation of C 3 H 6 O. This work will further enhance the study of the oxidation mechanism of oxygenated volatile organic pollutants over loaded noble metal catalysts., Competing Interests: Declaration of Competing Interest Hereby declare that the authors have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Recovering silver from wastewater not only significantly reduces environmental harm but also meets the growing demand for silver in modern industry. Here, a novel metal-organic framework adsorbent (MOF-RD) using rhodanine derivatives as linkers is introduced for the efficient and selective capture of silver ions in real wastewater. The adsorption of MOF-RD followed pseudo-second-order and Sips models, and thermodynamic investigations revealed the process to be endothermic. MOF-RD demonstrated a remarkable adsorption capacity of 707.2 mg·g -1 for Ag(I) at pH 5 and 318 K. The interaction between silver ions and MOF-RD was mainly electrostatic attraction and coordination, with coordination primarily occurring at the CO and CS sites within the rhodanine motif. The practical applicability of MOF-RD for selective adsorption of Ag(I) was validated in actual wastewater with high-concentration competing metal ions. Furthermore, after 10 adsorption-desorption cycle experiments, MOF-RD still retained a strong regenerative capability. The results reveal the good potential of MOF-RD as an adsorbent for selectively recovering Ag(I) from industrial wastewater. Additionally, the strategies and methods adopted in this article also provide new perspectives and technical paths for the separation and recovery of other metal ions in wastewater., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The Hartman Park community in Houston, Texas-USA, is in a highly polluted area which poses significant risks to its predominantly Hispanic and lower-income residents. Surrounded by dense clustering of industrial facilities compounds health and safety hazards, exacerbating environmental and social inequalities. Such conditions emphasize the urgent need for environmental measures that focus on investigating ambient air quality. This study estimated benzene, one of the most reported pollutants in Hartman Park, using machine learning-based approaches. Benzene data was collected in residential areas in the neighborhood and analyzed using a combination of five machine-learning algorithms (i.e., XGBR, GBR, LGBMR, CBR, RFR) through a newly developed ensemble learning model. Evaluations on model robustness, overfitting tests, 10-fold cross-validation, internal and stratified validation were performed. We found that the ensemble model depicted about 98.7% spatial variability of benzene (Adj. R 2 =0.987). Through rigorous validations, stability of model performance was confirmed. Several predictors that contribute to benzene were identified, including temperature, developed intensity areas, leaking petroleum storage tank, and traffic-related factors. Analyzing spatial patterns, we found high benzene spread over areas near industrial zones as well as in residential areas. Overall, our study area was exposed to high benzene levels and requires extra attention from relevant authorities., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest. The funders had no role in the study design; data collection, analyses, interpretation; writing of the manuscript; nor in the decision to publish the results., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Butylparaben, a common preservative, is widely used in food, pharmaceuticals and personal care products. Epidemiological studies have revealed the close relationship between butylparaben and diabetes; however the mechanisms of action remain unclear. In this study, we administered butylparaben orally to mice and observed that exposure to butylparaben induced glucose intolerance and hyperlipidemia. RNA sequencing results demonstrated that the enrichment of differentially expressed genes was associated with lipid metabolism, bile acid metabolism, and inflammatory response. Western blot results further validated that butylparaben promoted hepatic lipogenesis, inflammation, gluconeogenesis, and insulin resistance through the inhibition of the farnesoid X receptor (FXR) pathway. The FXR agonists alleviated the butylparaben-induced metabolic disorders. Moreover, 16 S rRNA sequencing showed that butylparaben reduced the abundance of Bacteroidetes, S24-7, Lactobacillus, and Streptococcus, and elevated the Firmicutes/Bacteroidetes ratio. The gut microbiota dysbiosis caused by butylparaben led to decreased bile acids (BAs) production and increased inflammatory response, which further induced hepatic glycolipid metabolic disorders. Our results also demonstrated that probiotics attenuated butylparaben-induced disturbances of the gut microbiota and hepatic metabolism. Taken collectively, the findings reveal that butylparaben induced gut microbiota dysbiosis and decreased BAs production, which further inhibited FXR signaling, ultimately contributing to glycolipid metabolic disorders in the liver., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The purpose of this research was to design and synthesize an adsorbent based on polyimide covalent organic frameworks (PICOFs) for uranium-containing wastewater treatment and uranium recovery. A modified solvothermal method was innovatively proposed to synthesize PICOFs with high specific surface area (1998.5 m 2 g -1 ) and regular pore structure. Additionally, a convenient functionalization strategy of PICOFs was designed through polydopamine (PDA) and a well-dispersed polymer (MPC-co-AO) containing multiple functional groups, forming stable composite (PMCA-TPPICOFs) in which the hydrogen bonding and cation-π interactions between PDA and MPC-co-AO played a key role. The obtained PMCA-TPPICOFs as an adsorbent exhibited strong selectivity for uranyl ions (maximum adsorption capacity was 538 mg g -1 ). In simulated wastewater with low uranium concentrations, the removal rate reached 98.3%, and the concentration of treated simulated wastewater met discharge standards. Moreover, PMCA-TPPICOFs was suitable for fixed-bed column adsorption because of its favorable structure. According to the research about adsorption mechanism, the adsorption primarily relied on electrostatic interaction and complexation. In summary, PMCA-TPPICOFs exhibited good potential for uranium-containing wastewater treatment, expanding the application of PICOFs. And the proposed functionalization strategy and modified solvothermal method may promote research in the fields of material functionalization and COFs synthesis. ENVIRONMENTAL IMPLICATION: Uranium is a raw material for nuclear energy applications, which is toxic and radioactive. If uranium is discharged with wastewater, it would not only pose a threat to the environmental protection and life safety, but also cause the loss of precious nuclear raw materials. Although adsorption was considered to be an effective way to remove uranium, many of the developed adsorbents were difficult to apply due to the harsh wastewater environment and complex preparation processes. This study reported a novel adsorbent and a new functionalization strategy, which was expected to solve the problem of uranium recovery in wastewater., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Clay minerals and iron (hydr)oxides are important geosorbents in controlling the migration of heavy metal cations in the environment. Despite the widespread occurrence of clay minerals/iron (hydr)oxides composites, their complex mutual effects on the fate of heavy metal cations are not well recognized. In this work, we investigated the effect of clay minerals on the redistribution of Cd(II) during the phase transformation of ferrihydrite containing coprecipitated Cd(II) (Cd-Fh). Three systems were considered: i.e., Cd-Fh, Cd-Fh/kaolinite composite, and Cd-Fh/montmorillonite composite. Our results showed that the transformation of Fh into goethite and hematite caused the release of Cd(II), while the presence of kaolinite and montmorillonite inhibited the phase transformation of Fh and the release of Cd(II), with montmorillonite being more effective in these process. Multiple factors contributed to the reduced release of Cd(II), including the retarded transformation of Fh, the buffering of solution pH, and the re-adsorption of the released Cd(II). Our findings show that clay minerals have multiple effects in reducing the release of heavy metal cations from Fh during its transformation process, which sheds new light on understanding the critical roles of nanominerals in modulating the migration and bioavailability of heavy metal cations in the environment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Mercury biomagnification in aquatic ecosystems is a global issue. Biomagnification patterns and drivers in alpine regions remain poorly understood. Hg biomagnification in the aquatic food web of the Qinghai-Tibetan Plateau (Q-T Plateau) was investigated. A total of 302 fish and macroinvertebrate tissue samples were analysed for total mercury (THg) and nitrogen (δ 15 N) stable isotope ratios. Overall, 26.75% of fish individuals exceeded the USFWS consumption guidelines. A total of 52.17% of the sampling sites covering different habitats exhibited a significantly positive THg-δ 15 N relationship, which confirmed the Hg biomagnification potential of Q-T Plateau aquatic ecosystems. The Q-T Plateau Hg biomagnification rates were generally far higher than global averages regardless of the habitat type. Hg in sediments, elevation and population density were positively related to the Hg biomagnification magnitude on the Q-T Plateau, which could be attributed to the disproportionate response of Hg concentrations in macroinvertebrates and fishes along environmental gradients. Our findings offer empirical evidence that fish consumption on the Q-T Plateau poses a substantial Hg exposure risk to people living along river and lake shores. Higher biomagnification rates could further disproportionately accelerate Hg pollution in Q-T Plateau aquatic ecosystems under future anthropogenic activities and climate warming trajectories., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Here, we show that the adverse environmental and health effects of tetracycline (TC) can be efficiently reduced by encapsulating Ag 3 PO 4 into MIL-101(Fe) to construct a Ag 3 PO 4 /MIL-101(Fe) heterojunction composite through advanced oxidation processes, such as Fenton catalysis, photocatalysis, and photo-Fenton catalysis. Notably, the reaction can be driven by natural sunlight and does not require any artificial energy source. Remarkably, the optimal degradation of TC can be achieved under different compositions of the composite system through photocatalysis and photo-Fenton catalysis. For photo-Fenton catalysis, the maximum degradation rate of TC (2.5730 min -1 ) is achieved when the mass ratio of MIL-101(Fe) to Ag 3 PO 4 in the composite is 5:1, which is 31.65- and 3.12-fold of that in the Ag 3 PO 4 + PDS + Sunlight and MIL-101(Fe) + PDS+ Sunlight catalyst systems, respectively. Moreover, the internal conversion of matrix during photocatalysis and Fenton catalysis processes inhibits the photocorrosion of Ag 3 PO 4 and improves the reusability of the composite. Furthermore, it is found that both radical and non-radical species participate in the TC degradation. Besides, the degradation products and catalytic mechanism of Ag 3 PO 4 and Ag 3 PO 4 /MIL-101(Fe) systems are explored. The toxicity evaluation results suggest that the intermediates produced during Ag 3 PO 4 /MIL-101(Fe) catalysis have a lower biotoxicity than those produced during Ag 3 PO 4 catalysis. Overall, this work provides an effective strategy to inhibit the inherent photocorrosion of Ag 3 PO 4 and establishes an efficient catalytic system for the treatment of organic-contaminated wastewater under natural sunlight conditions., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The formation of As(V) substituted hydroxylapatite (HAP) has a vital influence on the fate of As(V) in the environment. However, despite growing evidence showing that HAP crystallizes in vivo and in vitro with amorphous calcium phosphate (ACP) as a precursor, a knowledge gap exists concerning the transformation from arsenate-bearing ACP (AsACP) to arsenate-bearing HAP (AsHAP). Here we synthesized AsACP nano-particles with varied As contents and investigated the arsenic incorporation during their phase evolution. The phase evolution results showed that the transformation process of AsACP to AsHAP could be divided into three Stages. A higher As(V) loading significantly delayed the transformation of AsACP, increased the distortion degree, and decreased the crystallinity of AsHAP. NMR result showed that the PO 4 3- tetrahedral is geometrically preserved when PO 4 3- is substituted by AsO 4 3- . From AsACP to AsHAP, the As-substitution led to the transformation inhibition and As(V) immobilization., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Runliang Zhu reports financial support was provided by Fundamental and Applied Fundamental Research Major Program of Guangdong Province. Shijun Wu reports financial support was provided by Guangdong Basic and Applied Basic Research Foundation. Shijun Wu reports financial support was provided by National Natural Science Foundation of China. Tim White reports financial support was provided by Monetary Academic Resources for Research Grant. Yao Yan reports financial support was provided by China Scholarship Council., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Microbial-induced carbonate precipitation (MICP) is a promising technology to immobilize/remediate heavy metals (HMs) like cadmium (Cd). However, the long-term stability of MICP-immobilized HMs is unclear, especially in farmland where chemical fertilization is necessary. Therefore, we performed MICP treatment on soils contaminated with various Cd compounds (CdCO 3 , CdS, and CdCl 2 ) and added diammonium phosphate (DAP) to explore the impact of phosphate on the MICP-immobilized Cd. The results showed that MICP treatment was practical to immobilize the exchangeable Cd but to mobilize the carbonate and Fe/Mn oxide-bound Cd. After applying DAP, soil pH declined due to ammonium nitrification. At high P/Ca molar ratios (1/2 and 1), partial previously immobilized Cd was released due to the carbonate dissolution. Contrarily, exchangeable Cd transformed to less mobilizable Fe/Mn oxide-bound at low P/Ca molar ratios (1/4 and 1/8). Meanwhile, other treatments were also helpful in avoiding the release of immobilized Cd, such as applying non-ammonium phosphate and adding lime material after soil acidification. Our investigation suggested that the long-term stability of HMs in remediated sites should be carefully evaluated, especially in agricultural areas with phosphate and nitrogen fertilizer input., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Runliang Zhu reports financial support was provided by Fundamental and Applied Fundamental Research Major Program of Guangdong Province. Shijun Wu reports financial support was provided by National Natural Science Foundation of China. Shijun Wu reports financial support was provided by Guangdong Basic and Applied Basic Research Foundation. Shijun Wu reports financial support was provided by Science and Technology Planning Project of Guangdong Province., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Biogenic isoprene is an important pollutant for regional air quality. Being ubiquitously distributed on the earth surface, manganese (hydr)oxides should play a vital role in the transformation of isoprene. Cryptomelane is a typical manganese oxide with isomorphous substitution of Fe for Mn, but less attention has been paid to its heterogeneous reaction with isoprene. When Fe 3+ replaces Mn 3+ , K + is depleted and Mn 3+ is oxidized to Mn 4+ . In contrast, oxygen vacancies are formed when Fe 3+ substitutes Mn 4+ . Fe substitution creates weak crystallites and abundant mesopores, resulting in the increase of isoprene adsorption. As found by theoretical calculations, the Mn 4+ -O 2- bonds at the cross sections of the tunnels is more active than that on the outer wall of the tunnels. After the adsorption of isoprene, bridging carboxylate species and hydrogen-bonding water are produced and the surface octahedra are distorted, i.e., Mn 4+ O 6 → Mn 3+ O 6-δ . As the heat facilitates the breakage of Mn 4+ -O 2- , the increase of environmental temperature enhances the oxidation of isoprene. The above findings shed light on the effect of Fe substitution in cryptomelane to enhance the oxidation of isoprene, and illustrates that heterogeneous reaction with isoprene impairs the transformation of other environmental substances on cryptomelane., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Carbonate-bound uranium (U) is critical in controlling the migration of U in circumneutral to alkaline conditions. The potential release risk of carbonate-bound U should be concerned due to the contribution of mineral replacement. Herein, we explored the fate of U during the conversion process from microbial-induced calcite to hydroxylapatite (HAP) and investigated the phase and morphology evolution of minerals and the immobilization efficiency, distribution, and stability of U. The results showed that most calcite could convert to HAP during the conversion process. The aqueous residual U was below 1.0 mg/L after U-HAP formation, and the U removal efficiencies were enhanced by 20.0-74.4% compared to the calcite precipitation process. XRD and TEM results showed that the products were a mixture of HAP and uramphite. The elemental mapping results showed that most U concentrated on uramphite while a handful of U distributed homogeneously in calcite and HAP matrixes. The stability test verified that U-bearing HAP decreased the U solubility by 98-100% relative to calcite due to the uramphite formation and U incorporation into HAP. Our findings demonstrated that the combinations of microbial-induced calcite precipitation and calcite-HAP conversion could facilitate the U immobilization in treating radioactive wastewater and soil., (Copyright © 2022 Elsevier B.V. All rights reserved.)

This study comprehensively investigated arsenic's enrichment, distribution, and characteristics in tailings. XRD and SEM-EDS characterized the phase and morphology of tailings from various smelting processes. At the same time, the embedding characteristics of arsenic in the ore phase were analyzed by EPMA. The differences between arsenic's leading ore phase carriers in different recovery processes were found. It was discussed that this phenomenon would be related to the element-binding ability and the precipitation priority of the ore phase. The occurrence state of arsenic was discussed by sequential chemical extraction experiments. The proportion of leachable arsenic is higher than the low-risk limit, whatever which smelting method is adopted, which leads to high environmental risk. In the experiment of comparing the leaching toxicity of tailings by different leaching methods, the arsenic concentration in the leaching solution of tailings recovered by the flotation method exceeds the specified safety range. Although the tailings after reduction smelting did not show high leaching toxicity, a large number of accumulations also would not represent absolute safety., (Copyright © 2022 Elsevier B.V. All rights reserved.)

A key matter in heavy metal removal technology is to develop the adsorbents with efficient adsorption sites. In this study, an oxygen-rich covalent organic framework (JUC-505) was functionalized by carboxyl (-COOH) groups to form synergetic effects aiming for the removal of Cd(II) and Pb(II) ions. JUC-505-COOH shows a high Cd(II) uptake of 504 mg⋅g -1 surpassing most of the reported porous adsorbents. Meanwhile, the kinetics study shows a rapid adsorption process at a high initial concentration (100 mg⋅L -1 ), and the equilibrium can be reached within 5 min. We investigated the adsorption mechanism in-depth by density functional theory calculations, proving the synergistic effects of surface complexation and hydrogen-bond, which are from the post-modified -COOH groups and the in-situ oxygen atoms of JUC-505, respectively. Moreover, under the interference of common ions in natural water, the removal efficiency of Cd(II) is almost insusceptible, which sheds lights on the potential for the application in the natural water purification. In addition, the Pb(II) uptake (559 mg⋅g -1 ) and the adsorption kinetics also surpass most of the reported porous adsorbents., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Wastewater with complex compositions of both heavy metals and organic pollutants is of critical environmental and socioeconomic threat worldwide, which urgently requires feasible remediation technologies to target this challenge. In this study, natural chalcopyrite (CuFeS 2 , NCP), the most abundant copper-based mineral in the Earth's crust, has been discovered to be a heterogeneous catalyst that can activate peroxydisulfate (PDS) for the simultaneous degradation of organic pollutant Rhodamine B (RhB) and reduction of hexavalent chromium (Cr(VI)). Batch experimental results indicate that both RhB and Cr(VI) could be simultaneously removed under a near-neutral condition in NCP/PDS combined system. The radicals SO 4 •- and • OH generated from PDS activation are the main oxidative species detected by electron paramagnetic resonance (EPR) spectroscopy. SO 4 •- acted as a predominant role in RhB degradation, while Cr(VI) reduction is mainly attributed to the oxidization of S 2- and S 2 2- species on NCP surface, as well as the photoreduction performance of NCP, which could be enhanced by the intermediates generated from RhB degradation. Density functional theory (DFT) calculation results disclose that Fe is the critical catalytic site for PDS activation. This work demonstrates a user-friendly strategy for remediation of complex wastewater containing both heavy metal and organic pollutants by combining photoreduction and advanced oxidation processes (AOPs) with natural minerals. It paves a way for wastewater treatment by utilizing low-cost natural abundant minerals as catalysts., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Epidemiological evidence regarded the relations of phthalates with children's renal function and its underlying mechanism were largely unknown. We conducted a panel study using 287 paired urine-blood samples by repeated measurements of 103 children (4-13 years) across 3 seasons to explore effects of urinary phthalate metabolites on estimated glomerular filtration rate (eGFR) and the potential role of multiple cytokines. We found that mono-ethyl phthalate (MEP), monobutyl phthalate (MBP), mono-benzyl phthalate (MBzP) and mono-n-octyl phthalate (MOP) were significantly associated with eGFR reduction. Compared with the lowest quartile, MBP, MBzP and MEP in the third and fourth quartiles exhibited a graded decrease in eGFR. Meanwhile, weighted quantile sum regression analyses showed an inverse association of metabolites mixture with eGFR, to which MEP, MBzP, MOP were the major contributors. MEP also remained robust in multiple-phthalate model. Age and weight status might modify such relationships with significant interactions. Furthermore, eGFR related phthalate metabolites were associated with increased multiple cytokines, and CCL27, CXCL1 might be potential mediators between MEP and eGFR with mild mediated proportions. Accordingly, urinary phthalate metabolites were related to eGFR reduction in dose-response manner and multiple cytokines elevation, of which CCL27 and CXCL1 might partly mediate phthalate-associated decreased renal function among children., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Antimony (Sb) is the ubiquitous re-emerging contaminant greatly accumulated in sediments which has been revealed risky to ecological environment. However, the impacts of Sb (III/V) on microbes and plants in sediments, under different water management with presence of engineering materials are poorly understood. This study conducted sequential incubation of sediments (flooding, draining and planting) with presence of multiwall carbon nanotubes (MWCNTs) and Sb to explore the influence on microbial functional diversity, Sb accumulation and alfalfa traits. Results showed that water management and planting led to greater impacts of sediment enzyme activities and microbial community metabolic function and bioavailable Sb fractions (defined as sum of acid-soluble fraction and reducible fraction, F1 + F2). Available fractions of Sb (V) showed higher correlation to microbial metabolism (r = 0.933) than that of Sb (III) (r = -0.480) in planting stage. MWCNTs with increasing concentrations (0.011%, w/w) positively correlated to microbial community metabolic function in planting stage whereas resulted in decreasing of Sb (III/V) concentrations in alfalfa, although 0.01% MWCNT led to increase of Sb (V) and decrease of Sb (V) by 50.97% and 32.68% respectively. This study provided information for investigating combined ecological impacts of heavy metal and engineering materials under different water managing sediments., (Copyright © 2021 Elsevier B.V. All rights reserved.)

A novel graphene oxide-dicationic ionic liquid composite (GO-DIL) was prepared by modifying graphene oxide (GO) with a dicationic ionic liquid (DIL), 3,3'-(butane-1,4-diyl) bis (1-methyl-1H-imidazol-3-ium) chloride ([C 4 (MIM) 2 ]Cl 2 ). GO and GO-DIL were characterized by SEM, BET, FTIR, and XPS, and the materials were used for Cr(VI) adsorption. Batch adsorption studies showed that adsorption reached equilibrium within 40 min, and the optimal pH was 3, where the electrostatic attraction between GO-DIL and Cr(VI) was maximized. The maximum theoretical Cr(VI) adsorption capacity (q m ) was 271.08 mg g -1 , and q m remained above 228.00 mg g -1 after five cycles. The adsorption data were fitted well by both the pseudo-first-order kinetic model and the Langmuir model. Furthermore, thermodynamics calculations revealed that adsorption was a spontaneous endothermic process. Importantly, electrostatic attraction between Cr(VI) and the protonated imidazole N + of GO-DIL played a critical role in Cr(VI) adsorption, and Cr(VI) was reduced to Cr(III). Thus, GO-DIL is predicted to be an effective adsorbent for Cr(VI) and other heavy metal ions in wastewater., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Coprecipitation with calcium carbonate (CaCO 3 ) could decrease the bioavailability of arsenic (As). However, in a phosphate-rich environment, some CaCO 3 will be converted to hydroxylapatite (HAP). Currently, the behavior of carbonate-bound As during conversion is unclear. Therefore, we prepared bio-induced CaCO 3 in an As solution and converted it to HAP. The results showed that a high concentration of arsenate promoted vaterite precipitation and the conversion of CaCO 3 to HAP. The dissolution data verified the low solubility of As in HAP, though its As-bearing CaCO 3 precursor released up to 88.19% As during the conversion. Furthermore, HPLC-ICP-MS data showed partial oxidation of arsenite to arsenate, suggesting that CaCO 3 and HAP's structure favored the incorporation of arsenate. Our results demonstrated that the stability of heavy metal-bearing CaCO 3 should be considered, and the role of HAP in the immobilization of heavy metals such as As should not be overestimated., (Copyright © 2021 Elsevier B.V. All rights reserved.)

As the dominant mercury species in fish, methylmercury (MeHg) biomagnifies during its trophic transfer through aquatic food webs. MeHg is known to bind to cysteine, forming the complex of MeHg-cysteine. However, relationship between MeHg and cysteine in large-scale food webs has not been explored and contrasted with MeHg biomagnification models. Here, we quantified the compound-specific nitrogen isotopic analysis of amino acids (CSIA-AA), MeHg, and amino acid composition in aquatic organisms of Poyang Lake, the largest freshwater lake in China. The trophic positions (TP AA ) of organisms ranged from 1.0 ± 0.1-3.7 ± 0.2 based on CSIA-AA approach. The trophic magnification factor (TMF) of MeHg, derived from the regression slope of Log-transformed MeHg in organisms upon their TP AA for the entire food web was 9.5 ± 0.5. Significantly positive regression between MeHg and cysteine (R 2  = 0.64, p < 0.01) was documented, suggesting MeHg-cysteine complex may potentially play a critical role in the bioaccumulation of MeHg. Furthermore, TMFs of MeHg calculated with and without cysteine normalization compared well (7.7-8.7) when excluding primary producers. Our results implied that MeHg may biomagnify as the complex of MeHg-cysteine and contribute to our understanding of MeHg trophic transfer at the molecular level., (Copyright © 2020. Published by Elsevier B.V.)

Microbial degradation is an important option for combating antibiotic pollution. Arthrobacter nicotianae OTC-16 was isolated as a novel tetracycline-degrading bacterium, which could degrade oxytetracycline/tetracycline (OTC/TET). Toxicity assessment indicated that this bacterium effectively converted OTC into byproducts with less toxicity to bacterial and algal indicators. Six degradation products of OTC were tentatively identified, and a potential biotransformation pathway was proposed that includes decarbonylation, reduction, and dehydration. Bioaugmentation of TC removal with this bacterium was further studied in various matrices. In aqueous media, strain OTC-16 accelerated OTC removal over a temperature range of 20-35 ℃, pH range of 6.0-9.0, and OTC concentration range of 25-150 mg L -1 . The strain also facilitated the decrease of OTC and TET concentrations in both swine and chicken manures, with a maximum decrease of 91.54%, and increased the degradation of OTC in soils by 8.22-45.45%. A unique advantage of this bacterium in promoting OTC degradation in alkaline environments was demonstrated, where it successfully competed with the indigenous microbiota and largely decreased the relative abundances of the studied tetracycline resistance genes (tetB and tetW) in soil. This work offers a better understanding of the antibiotic bioaugmentation and new microbial sources., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Zero-valent Cu-Fe bimetallic porous carbon materials were successfully applied to remediate organic wastewater. In this work, we successfully recycled the layered double hydroxides (LDHs) adsorbed with Orange II (OII) to form a zero-valent Cu-Fe bimetallic porous carbon material (CuFe/Carbon). The characterization results showed that CuFe/Carbon was a zero-valent Cu-Fe bimetallic porous graphene-like carbon material. In the course of the experiment, we found that aeration condition had a great influence on the activity of CuFe/Carbon. The removal efficiency of nitrobenzene (NB) was 100 % in nitrogen system and 48 % in air system. The active species of O 2 - and OH was formed under air condition, while there was no active species under nitrogen condition. NB was reduced to aniline directly under nitrogen condition. We proposed there were reduction and oxidation mechanisms under different aeration conditions. This work mainly investigated the conversion process of a novel material under different reaction conditions, which provided theoretical support for the removal of organic matters., (Copyright © 2020 Elsevier B.V. All rights reserved.)

As one of the most toxic heavy elements, humans are mainly exposed to cadmium (Cd) via daily diets and smoking. Calcite can be used as an amendment directly or precipitated in situ based on microbial-induced carbonate precipitation (MICP) technology to immobilize Cd in soil with potential release of Cd due to calcite dissolution. Therefore, we converted microbial-induced calcite to less soluble hydroxyapatite and investigated the phase and morphology evolutions of the solids, as well as the immobilized efficiency, distribution and release of Cd. The results showed that the conversion of calcite to hydroxyapatite enhanced Cd removal efficiency up to 1.67% and 33.14% compared to the MICP process and adsorption by calcite, respectively. Accordingly, the released Cd decreased up to 94.10% and 99.96%, respectively. Our findings demonstrated that the conversion of calcite to hydroxyapatite might control the environmental behavior of heavy metals like Cd and can potentially be applied for soil remediation., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Biomineralization is an interesting naturally occurring process of forming minerals by microorganisms, which offers an efficient way to sequester heavy metal ions within relatively stable solid phases. In this study, Bacillus cereus Cd01 was selected to investigate effects of self-mediated pH on biosorption and biomineralization of Cd 2+ in whole 72h cultivation period. Results revealed that strain Cd01-mediated pH decrease of the cultivation medium from 7.0 to 6.1 inhibited biosorption of Cd 2+ on Cd01 cells at the initial cultivation period, while an increased pH from 6.1 to 7.4 facilitated biosorption of Cd 2+ on Cd01 cells at the middle and late cultivation period. The reasons were mainly that self-mediated pH altered cell surface hydrophobicity and cell membrane fluidity of strain Cd01. Moreover, biosorption and bioaccumulation of Cd 2+ on Cd01 cells in the period of increased pH promoted biomineralization of Cd 2+ observed by the transmission and scanning electron microscopes. The analyses of energy dispersive spectroscopy, X-ray photoelectron spectroscopy and select area electron diffraction demonstrated that Cd 2+ loaded on Cd01 cells was biomineralized into polycrystalline and/ or amorphous cadmium sulfide and cadmium phosphate. These results suggest that strain Cd01 may play a potential role in biomineralization remediation of heavy metal contaminated soils., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Ag 2 O nanoparticles-loaded Bi 5 O 7 I microspheres forming a three dimensional Ag 2 O/Bi 5 O 7 I p-n heterojunction photocatalyst with wide-spectrum response were synthesized in this study. The results of transmission electron microscopy observations revealed that the Ag 2 O nanoparticles with the diameter of ca. 10-20nm were distributed on the surfaces of Bi 5 O 7 I nanosheets. The as-synthesized Ag 2 O/Bi 5 O 7 I exhibited an excellent wide-spectrum response to wavelengths ranging from ultraviolet (UV) to near-infrared (NIR), indicating its potential for effective utilization of solar energy. Compared with pure Bi 5 O 7 I, the Ag 2 O/Bi 5 O 7 I composite also demonstrated excellent photocatalytic activity for the degradation of Bisphenol A and phenol in aqueous solution under visible LED light irradiation. Among samples, the 20% Ag 2 O/Bi 5 O 7 I composite photocatalyst showed the highest photocatalytic activity for the degradation of Bisphenol A and phenol in aqueous solution. In addition, the 20% Ag 2 O/Bi 5 O 7 I composite also exhibited a photocatalytic activity for the degradation of Bisphenol A under NIR light irradiation. The improved photocatalytic activity is attributed to the formation of a p-n heterojunction between Ag 2 O and Bi 5 O 7 I, allowing the efficient utilization of solar energy (from UV to NIR) and high separation efficiency of photogenerated electron-hole pairs. The present work is desirable to explore a possible avenue for the full utilization of solar energy., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In this study, a series of Mn substituted spinel ferrites calcinated at different temperatures were used as catalysts for the oxidation of formaldehyde (HCHO). X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and H2 temperature-programmed reduction were conducted to characterize the structure and physico-chemical properties of catalysts, which were affected by calcination in the range of 200-600°C. Results show that all the ferrites were with spinel structure, and those calcinated in the range of 300-600°C were in the phase of maghemite. The calcination changed the valence and distribution of Mn and Fe on the ferrite surface, and accordingly the reducibility of ferrites. The HCHO catalytic oxidation test showed that with the increase of calcination temperature, the activity was initially improved until 400°C, but then decreased. The variation of HCHO conversion performance was well positively correlated to the variation of reduction temperature of surface Mn(4+) species. The remarkable effect of calcination on the catalytic activity of Mn-doped spinel ferrites for HCHO oxidation was discussed in view of reaction mechanism and variations in cationic microstructure of Mn-doped ferrites., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Adsorption has been considered as an efficient method for the treatment of dye effluents, but proper disposal of the spent adsorbents is still a challenge. This work attempts to provide a facile method to reutilize the spent Mg/Al layered double hydroxide (Mg/Al-LDH) after the adsorption of orange II (OII). Herein, the spent hybrid was carbonized under the protection of nitrogen, and then washed with acid to obtain porous carbon materials. Thermogravimetric analysis results suggested that the carbonization could be well achieved above 600°C, as mass loss of the spent hybrid gradually stabilized. Therefore, the carbonization process was carried out at 600, 800, and 1000°C, respectively. Scanning electron microscope showed that the obtained carbon materials possessed a crooked flaky morphology. Nitrogen adsorption-desorption results showed that the carbon materials had large BET surface area and pore volume, e.g., 1426 m(2)/g and 1.67 cm(3)/g for the sample carbonized at 800°C. Moreover, the pore structure and surface chemistry compositions were tunable, as they were sensitive to the temperature. Toluene adsorption results demonstrated that the carbon materials had high efficiency in toluene removal. This work provided a facile approach for synthesizing porous carbon materials using spent Mg/Al-LDH., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Linear free energy relationships (LFERs) were applied to investigate the sorptive characteristics of organic contaminants (OCs) on organoclays from water. Three cetyltrimethylammonium modified montmorillonites (C-Mts) were selected as representative organoclays. The sorption coefficients (logK(oc)) of OCs on the C-Mts were calculated according to the results of batch sorption experiments. Then the LFER equations for OC sorption on C-Mts from water were developed. The results of this study showed that compared with bulk water, water saturated C-Mts are more polarizable, less polar and cohesive, and have stronger H-bond acceptor capacities and weaker H-bond donor capacities. The primary driving forces for the sorption of OCs from water to C-Mts can be ascribed to the weaker cohesive characteristics of C-Mts as well as the stronger nonspecific Van der Waals interaction between OCs and C-Mts. With increasing CTMA loading amount, the interaction between OCs and C-Mts increases whereas the C-Mts become more cohesive. Consequently, the sorption capacity of C-Mts first increases with CTMA loading amount and then decreases with further increased loading amount., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The major objective of the present study was to investigate the role of iron and manganese on the formation of haloacetic acids (HAAs) when algae are chlorinated at different pHs. The results showed that both iron and manganese can reduce the yields of dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) on chlorinating green alga Chlorella vulgaris (C. vulgaris) at a pH range of 6.0-9.0, and the decline of DCAA and TCAA was shown to be more significant at the low pH range. At pH 6.0, DCAA and TCAA yields decreased by 44.5% and 57.3%, respectively with the addition of 0.5 mg L(-1) iron, and decreased 39.5% and 49.4%, respectively with the addition of 0.5 mg L(-1) manganese. The main reason for decreasing the yields of HAAs as shown by scanning electron microscope (SEM) is that Fe(OH)(3(am)) or MnO(2(am)) coat the algal cells, which then improves their agglomeration of algal cells which is also revealed by the laser particle size analysis (LPSA)., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Molecularly imprinted polymers for bisphenol A (BPA) were prepared by using surface molecular imprinting technique. Analogues of BPA, namely 4,4'-dihydroxybiphenyl and 3,3',5,5'-tetrabromobisphenol A, were used as the dummy templates instead of BPA, to avoid the leakage of a trace amount of the target analyte (BPA). The resulting dummy molecularly imprinted polymers (DMIPs) showed the large sorption capacity, high recognition ability and fast binding kinetics for BPA. The maximal sorption capacity was up to 958 micromol g(-1), and it only took 40 min for DMIPs to achieve the sorption equilibrium. The DMIPs were successfully applied to the solid-phase extraction coupled with HPLC/UV for the determination of BPA in water samples. The calibration graph of the analytical method was linear with a correlation coefficient more than 0.999 in the concentration range of 0.0760-0.912 ng mL(-1) of BPA. The limit of detection was 15.2 pg mL(-1) (S/N=3). Recoveries were in the range of 92.9-102% with relative standard deviation (RSD) less than 11%. The trace amounts of BPA in tap water, drinking water, rain and leachate of one-off tableware were determined by the method built, and the satisfactory results were obtained., (2010 Elsevier B.V. All rights reserved.)

The saturated level of cationic exchange capacity (CEC) of bentonite by organic cations can significantly influence the sorption capacity of the resulting organobentonites. In this work cationic polyacrylamide (CPAM) was applied to saturate part of the CEC of the cetyltrimethylammonium (CTMA) modified bentonite, with the aim to enhance their sorption capacity. XRD was applied to investigate the basal spacings of the organobentonites with and without CPAM, and the sorption characteristics of the organobentonites towards phenol and nitrobenzene to CTMA-bentonite was also studied. The XRD characterization results showed that the resulting organobentonites (C/P-Bt) had larger basal spacings than the CTMA modified bentonite (C-Bt), which indicated that both CPAM and CTMA could intercalate into the interlayer spaces of C/P-Bt. The saturated CEC of C/P-Bt increased with the intercalated amounts of CPAM. The sorption coefficients (K(d)) of phenol and nitrobenzene on C/P-Bt were shown to first increase with the saturated CEC until the maximum, and then began to decrease as the saturated CEC further increased. The maximum increase of K(d) reached 41% and 23% for phenol and nitrobenzene, respectively, which could be ascribed to the enhanced affinity of the adsorbed CTMA aggregates towards the sorbates. Results of this work showed that the simultaneous intercalation of CPAM could be a novel method to enhance the sorption capacity of the traditional organobentonites., (Copyright 2010 Elsevier B.V. All rights reserved.)

Diatomite-supported/unsupported magnetite nanoparticles were prepared by co-precipitation and hydrosol methods, and characterized by X-ray diffraction, nitrogen adsorption, elemental analysis, differential scanning calorimetry, transmission electron microscopy and X-ray photoelectron spectroscopy. The average sizes of the unsupported and supported magnetite nanoparticles are around 25 and 15 nm, respectively. The supported magnetite nanoparticles exist on the surface or inside the pores of diatom shells, with better dispersing and less coaggregation than the unsupported ones. The uptake of hexavalent chromium [Cr(VI)] on the synthesized magnetite nanoparticles was mainly governed by a physico-chemical process, which included an electrostatic attraction followed by a redox process in which Cr(VI) was reduced into trivalent chromium [Cr(III)]. The adsorption of Cr(VI) was highly pH-dependent and the kinetics of the adsorption followed a pseudo-second-order model. The adsorption data of diatomite-supported/unsupported magnetite fit well with the Langmuir isotherm equation. The supported magnetite showed a better adsorption capacity per unit mass of magnetite than unsupported magnetite, and was more thermally stable than their unsupported counterparts. These results indicate that the diatomite-supported/unsupported magnetite nanoparticles are readily prepared, enabling promising applications for the removal of Cr(VI) from aqueous solution.

This work aimed to develop novel bentonite based sorbents that could simultaneously remove hydrophobic organic compounds (HOCs) and phosphate from water. Cetyltrimethyl ammonium bromide (CTMAB) and hydroxy-aluminum (Al(13)) were used to intercalate bentonite simultaneously or sequentially to prepare series of inorganic-organic bentonites (IOBs). Structures of the prepared IOBs were characterized, and their sorptive characteristics towards naphthalene and phosphate were investigated. Results showed that both CTMAB and Al(13) could intercalate into bentonite's interlayers if they were simultaneously used or if CTMAB was first used for the intercalation. The resulting IOBs were as effective as the CTMAB modified bentonites in sorption of naphthalene from water, and they were shown to be more effective in sorption of phosphate from water than the Al(13) pillared bentonite. However, if Al(13) was first used for the intercalation, the interlayers of the bentonites would be "locked" by the intercalated Al(13), and thus CTMAB could hardly further intercalate bentonite. As a result, the obtained IOBs showed weak sorption efficiency towards naphthalene, and its sorption capacity towards phosphate was also lower than the corresponding Al(13) pillared bentonites. Results of this work showed that IOBs prepared with proper processes could be efficient sorbents towards both HOCs and phosphate.

This work was to examine the feasibility and efficiency to use bentonite for simultaneous removal of cationic dyes and hydrophobic organic carbons (HOCs) from water. The sorption capacities of crystal violet (CV) on two bentonites and one activated carbon were compared. Simultaneous sorption of CV and 2-naphthol on the two bentonites were tested, and the removal efficiencies of 2-naphthol by the simultaneous sorption method and by CV modified bentonite was also compared. The experimental results in this study showed that the bentonite is more effective in sorption of CV than the activated carbon. With the sorption of CV, bentonite surfaces were altered from hydrophilicity to hydrophobicity, and thus 2-naphthol could be simultaneously removed. The aromatic effect between CV and 2-naphthol was supposed to be the primary driving force for the sorption of 2-naphthol. The simultaneous sorption method was shown to be more effective in the sorption of 2-naphthol than the CV modified bentonite. Results of this work could provide novel information for the treatment of wastewater containing both cationic dyes and HOCs.