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Objective: To systematically explore the effect and mechanism of melastomatis dodecandri herba (Melastoma dodecandrum Lour.) in the treatment of hepatitis based on network pharmacology. Method: We evaluated the hepatoprotective effects of M. dodecandrum in concanavalin A (Con A)-induced hepatitis in mice by assessing survival rate, histological analysis, serum transaminases, and related cytokines. Then the mechanism of action was predicted by a network pharmacology-based strategy. Based on the results, we measured the hepatic expression of related genes at mRNA level and proteins related to the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) and nuclear factor-kappa B (NF-кB) pathways. Results: Our study results clearly demonstrated that M. dodecandrum pretreatment significantly alleviated liver injury. This was demonstrated by an increase in survival rate, decreased severity of liver damage, and reduced serum transaminase levels compared with those in the Con A group. Moreover, M. dodecandrum significantly reduced the serum levels of tumor necrosis factor-α, interleukin-6, and interferon-γ and increased the liver levels of superoxide dismutase, which indicated that M. dodecandrum exhibits anti-inflammatory and antioxidant activities. On the basis of network pharmacology, 50 nodes were selected as major hubs based on their topological importance. Pathway enrichment analyses indicated that the putative targets of M. dodecandrum mostly participate in various pathways associated with the anti-inflammation response, which implies the underlying mechanism by which M. dodecandrum acts on hepatitis. Real-time fluorescent quantitative PCR analysis showed that M. dodecandrum downregulates the mRNA expression of interleukin-6, Toll-like receptor 7, interleukin-1 receptor-associated kinase-4, NF-кB and tumor necrosis factor-α in liver tissues. Western blotting showed that M. dodecandrum pretreatment protected against inflammation through activating the PI3K-Akt pathway by upregulating phosphorylated Akt (p-Akt) expression and suppressing NF-кB activation by inhibiting the phosphorylation of IKK, IκBα, and p65. Conclusion: The present work demonstrated the hepatoprotective effects of M. dodecandrum by regulating the PI3K/Akt and NF-кB pathways in Con A-induced mice, which provide insights into the treatment of hepatitis using M. dodecandrum.

Metal-organic framework (MOFs) composites are new kind of porous materials, with great specific surface area and extremely high porosity. MOFs have been in the catalytic application due to excellent catalytic properties such as, their unique structure and dispersed active centers. Hence, the chemical, environment and energy-related fields disciplines have made substantial applications of MOFs and its composites. Moreover, several researchers have made conducted extensive studies regarding the application of MOFs materials for air pollution control such as, including functionalization, loading, carbonization, oxidation of MOFs materials, and application of MOFs as sensors for air pollution monitoring. This review article is aimed at providing precise information about the efforts made by some researchers in the field of MOFs and MOFs derived materials and their application in other disciplines. The following areas have been succinctly reviewed: (1) general introduction of MOFs materials, (2) synthesis of various MOFs materials, composites and their derivatives, (3) catalysis of MOFs materials, composites and their derivatives on different air pollution, (4) summary and future prospects. We hope this review will help researchers understand more about the research progress of MOFs materials in the catalysis of air pollution.

2D carbon ribbon/Al2O3 was synthesized with two-dimensional metal organic frameworks 2D-MOFs as precursors using the solvothermal and calcination methods. Batch experiments of adsorption parameters such as pH, liquid/solid ratio, adsorption kinetics, adsorption thermodynamics, and anions competitions were investigated to understand the adsorptive behavior of fluoride on carbon ribbon/Al2O3 and nitrogen-doped carbon ribbon/Al2O3. The adsorption of fluoride on carbon ribbon/Al2O3 could be described as the chemical and multilayer adsorption, while the adsorption of fluoride on nitrogen-doped carbon ribbon/Al2O3 followed the chemical and monolayer adsorption phenomenon. The fluoride on nitrogen-doped carbon ribbon/Al2O3 had a much faster adsorption rate of 3.1×10−7 m/s than carbon ribbon/Al2O3, which was 1.2×10−7 m/s. The nitrogen-doping on carbon ribbon enhances structural defects and improves the adsorption performance of fluoride. Also, the diacetylene linkages (—C≡C—) and pyridinic-N were studied to understand their influences on removing fluoride. The result indicates that carbon ribbon and nitrogen-doped ribbon could serve as good adsorbents for removing fluoride.

International audience; Thermococcus gammatolerans is anaerobic euryarchaeon which grows optimally at 88 °C and its genome encodes a family B DNA polymerase (Tga PolB). Herein, we cloned the gene of Tga PolB, expressed and purified the gene product, and characterized the enzyme biochemically. The recombinant Tga PolB can efficiently synthesize DNA at high temperature, and retain 93% activity after heated at 95 °C for 1.0 h, suggesting that the enzyme is thermostable. Furthermore, the optimal pH for the enzyme activity was measured to be 7.0–9.0. Tga PolB activity is dependent on a divalent cation, among which magnesium ion is optimal. NaCl at low concentration stimulates the enzyme activity but at high concentration inhibits enzyme activity. Interestingly, Tga PolB is able to efficiently bypass uracil in DNA, which is distinct from other archaeal family B DNA pols. By contrast, Tga PolB is halted by an AP site in DNA, as observed in other archaeal family B DNA polymerases. Furthermore, Tga PolB extends the mismatched ends with reduced efficiencies. The enzyme possesses 3′-5′ exonuclease activity and this activity is inhibited by dNTPs. The DNA binding assays showed that Tga PolB can efficiently bind to ssDNA and primed DNA, and have a marked preference for primed DNA. Last, Tga PolB can be used in routine PCR.

Metal-organic frameworks (MOFs) based membranes with superior mechanical properties are of particular interest in purification, separation, and catalysis. Nevertheless, their fabrication still remains a grand challenge. Here, fungus hyphae (Mucor) were used as a robust scaffold to load the MOFs and induced the formation of porous and flexible membranes. ZIF-8 was used as a representative of MOFs. The ZIF-8@Mucor membrane was formed by the in-situ growth of ZIF-8 on hyphae and then a vacuum filtration of the ZIF-8/hyphae composite. ZIF-8 was effectively dispersed on the ZIF-8@Mucor membrane, and the shear modulus of ZIF-8@Mucor-3 was 864 MPa by calculation. The ZIF-8@Mucor membrane exhibited promising properties for adsorption application to remove the highly toxic Pb2+. The adsorption capacity of this membrane was as high as 1443.29 mg/g. Results from dynamic adsorption indicated that the penetration concentration of Pb2+ ions was less than 5% of the original level before 80 min whereas after 160 min, penetration concentration of Pb2+ ions was more than 90%. This study would open a new way of how to synthesize composite MOFs/bacterial membranes for energy and environment purposes.

Uranium is well-known to have serious adverse effects on the ecological environment and human health. Bioremediation stands out among many remediation methods owing to its being economically feasible and environmentally friendly. This study reported a great promising strategy for eliminating uranium by Stenotrophomonas sp. CICC 23833 in the aquatic environment. The bacterium demonstrated excellent uranium adsorption capacity (q

This study aims to examine the cytotoxicity mechanisms of synthetic cathinone (bath salts) on rat primary cultured neurons and primary astroglial cells, and to assess their neurobehavioral effects on mice. We administered methylenedioxypyrovalerone (MDPV) to both rat primary cultured neurons and primary astroglial cells to assess cell injury. We also analyzed the effects of MDPV on these cell cultures using immunocytochemistry. We utilized western blotting to assess the breakdown of αII-spectrin and glial fibrillary acidic protein (GFAP) induced by MDPV. The western blotting experiment also included calpain and caspase inhibitors (SNJ1945 and Z-D-DCB, respectively) and pro-apoptotic and pro-necrotic agents (Staurosporine and calcium ionophore A23187, respectively). Lastly, we assessed MDPV’s effects on behavioral effects using rotarod, locomotor activity, elevated plus maze, Morris water maze, forced swimming, and open field tests. MDPV caused a dose-dependent release of LDH in both cerebrocortical neuron-astroglia mixed cultures and primary astroglial cultures. MDPV also caused neurite breakages and astroglial process retraction on immunocytochemistry. Lastly, MDPV induced αII-spectrin breakdown in western blotting experiments. Co-administration of calpain and caspase inhibitors reduced the degradation of αII-spectrin and GFAP. MDPV administration also increased anxiety-like behavior and locomotor activity in the mice. Synthetic cathinones, which share structural similarities with methamphetamine, also induce significant neurotoxic effects and neurobehavioral effects on rodent models. These neurotoxic effects are likely mediated by calpain and caspase-induced apoptosis and necrosis, while astroglial death is likely only due to calpain activation. Therefore, further research may focus on pharmacological interventions targeting these pathways to mitigate the cytotoxic impact of cathinones in humans.

The oxidation of arsenic restricts its application in high-performance electronic devices and functional materials. Herein, a removable iodine-regulation method was proposed for the first time to enhance the anti-oxidation behavior of arsenic. In a gradient of 500-650 ℃, the introduction of 0.6-5.0 at% iodine into arsenic vapor could regulate an arsenic crystal. The oxygen content on the regulated arsenic crystal surface was lowered below 2.5 at% after exposure to ambient conditions for 96 h, reducing over 90% compared with the control group. The residual iodine barrier, which was mainly in the As-I

Silicosis is a systemic disease characterized by diffuse fibrosis of the lung tissue caused by long-term inhalation of large amounts of free silica (SiO

CuO nanoparticles (NPs) released into aqueous environments induce metal toxicity, which generally exerts negative effects on various organisms and leads to great challenge for wastewater biotreatment. In this study, a promotion effect of CuO NPs on biological process was first found. Cr(VI) reduction by Cupriavidus basilensis B-8 (hereafter B-8) was enhanced in the presence of CuO NPs. The efficiency of Cr(VI) bioreduction was much higher with B-8 and CuO NPs (approximately 100%) than with B-8 (approximately 37.6%) and CuO NPs (39.9–44.7%) alone, indicating a stimulatory effect of CuO NPs on Cr(VI) reduction by B-8. Our material analyses revealed different response mechanisms of B-8 to Cr(VI), with and without CuO NPs. The addition of CuO NPs influenced the interaction of Cr(VI) with the N-, P-, S-, and C-related functional groups of B-8. Transcriptomic analysis indicated that multiple mechanisms, including Cr(VI) uptake and reactive oxygen species detoxification, were induced by Cr(VI). Many genes involved in various metabolic processes were significantly upregulated by the addition of CuO NPs. To a certain extent, the pressure of DNA repairment by B-8 induced by Cr(VI) was also alleviated by the presence of CuO NPs. They contributed to facilitate B-8 growth and enhance Cr(VI) reduction, even with 50 mg/L Cr(VI). This study not only elaborated the mechanisms of bacterial Cr(VI) reduction when enhanced by CuO NPs, but also provided a novel perspective for wastewater biotreatment.

Bioremediation plays an increasingly important role in the remediation of chromium-contaminated soil because it is an environmentally friendly technology. To investigate the Cr(VI) reduction process by indigenous microorganisms in soil, a batch of incubation experiments were carried out in a bioreactor under aerobic conditions. The results showed that in the presence of indigenous microorganisms, the Cr(VI) concentration in the chromium-contaminated soil decreased from 1521.9 to 199.2 mg/kg within 66 h with culture medium addition, while a slight decrease in the Cr(VI) concentration was found in the sterilized soil, implying that the indigenous microorganisms contributed to the Cr(VI) reduction. In the microbial remediation process, Cr(VI) microbial reduction occurred after the reduction of, Mn 4+ and Fe 3+ and, before reduction. The reduction process of Cr(VI) can be divided into two phases, characterized by the exponential equation model of microbial reduction and the linear equation model of the combined effect of the major ions. It can be concluded that indigenous Cr(VI)-reducing bacteria have a potential application for in-situ remediation of Cr(VI)-contaminated soil.

Coordination bonds of ligands and metal ions are generally considered for improving agglomeration during the synthesis of metal oxides. However, the strong interactions always limit the performance due to the requirement of additional energy and calcination. A new strategy of synthesizing ZnO particles is proposed through a hydrothermal inducing redox method by using 2-methyl imidazole and Zn(NO3)2. In situ direct redox between this organic ligand and NO3− in a hydrothermal condition is confirmed radical change instead of the simple coordination between organic ligands with Zn2+ in traditional method. The directly acquired ZnO particles possessing uniform dumbbell-like morphology have no obvious agglomeration. The yield reaches >95%. In particular, the synthesis mechanism and morphology evolution during the ZnO aggregates growth were carefully explored and proposed. Density functional theory (DFT) and surface energy calculations demonstrated the effects of activity variation of reactive groups and preferred growth surface of ZnO crystals. This work gives new insights into new synthesis strategy of ZnO particles via hydrothermal condition.

In monsoonal areas, the ocean transports water vapor to inland areas and affects the stable isotopes of precipitation in inland areas, leading to that stable isotopes of precipitation could be used as a medium to study large-scale water vapor cycles. Analysis of the characteristics of δ18O and δ2H indicates that stable isotopes of precipitation in the Shiyang River Basin (SRB) exhibit obvious seasonal changes. The slope and intercept of the local meteoric water line (LMWL) in summer and autumn are lower than those in spring and winter, which is similar to the typical monsoon climate zone, indicating that large-scale monsoon water vapor is the main source of precipitation in the SRB. Regional-scale (equatorial North Pacific) cloud cover and outgoing longwave radiation (OLR) have a stronger impact on the East Asian monsoon edge area, there is a significant negative correlation between cloud cover in the equatorial North Pacific and precipitation stable isotopes in the SRB, and there is a positive correlation between OLR in the equatorial North Pacific and precipitation stable isotopes in the SRB. The cloud cover on the fifth day before precipitation in the equatorial North Pacific has the greatest impact on precipitationδ18O in the SRB. In the region with the highest correlation coefficient (the equatorial North Pacific), the correlation between precipitation δ18O and high cloud cover is greater than that between precipitation δ18O and medium cloud cover or low cloud cover, indicating that cloud cover has the most significant influence on precipitation stable isotopes in the middle troposphere (3–8 km).

Here, Pannonibacter phragmitetus BB was investigated at genomic, genetic and protein levels to explore molecular mechanisms of chromium biotransformation, respectively. The results of Miseq sequencing uncovered that a high-qualified bacterial genome draft was achieved with 5.07 Mb in length. Three novel genes involved in chromate reduce and transport, named nitR, chrA1 and chrA2, were identified by alignment, annotation and phylogenetic tree analyses, which encode a chromate reductase (NitR) and two chromate transporters (ChrA1 and ChrA2). Reverse transcription real-time polymerase chain reaction (RT-qPCR) analyses showed that the relative quantitative transcription of the three genes as the maximum reduction rate of Cr(VI) were significantly up-regulated with the increasing initial Cr(VI) concentrations. However, at the maximum cell growth points nitR was in a low transcription level, while the transcription of chrA1 and chrA2 were hold at a relatively high level and decreased with the increasing initial Cr(VI) concentrations. The ex-situ chromate reducing activity of NitR was revealed a Vmax of 34.46 µmol/min/mg enzyme and Km of 14.55 µmol/L, suggesting feasibility of the reaction with Cr(VI) as substrate. The multiple alignment demonstrates that NitR is potentially a nicotinamide adenine dinucleotide phosphate (NADPH) dependent flavin mononucleotide (FMN) reductase of Class I chromate reductases. Our results will prompt a large-scaled bioremediation on the contaminated soils and water by Pannonibacter phragmitetus BB, taking advantage of uncovering its molecular mechanisms of chromium biotransformation.

Millions of tons of iron-bearing manganese residue are produced as a by-product of the electrolytic manganese industry. And the environmental contamination caused by manganese residue has received increasing attention. This paper focuses on the recovery of iron and manganese from high iron-bearing manganese residues. Manganese ferrite in manganese residues is initially decomposed by oxidative roasting, and the intermediates are magnetized in a reductive roasting step. The roasted product is milled and subjected to multi-stage magnetic separation. The optimum conditions are as follows: roasting at 750 °C under air flow for 30 min, roasting in a CO atmosphere at 750 °C for 30 min, and separating under a magnetic intensity of 1000 G for weak magnetic separation and of 12,000 G for strong magnetic separation. The recovery and grade of iron in the iron concentrate were 72.29% and 62.21%, respectively, and those of manganese in the manganese concentrate were 90.75% and 35.21%, respectively. This study demonstrates that the combination of roasting and magnetic separation provides a promising process for the recovery of iron and manganese from high-iron-bearing manganese residues.

A novel efficient adsorbent of bacterial cellulose/poly(m-phenylenediamine (BC/PmPD) was prepared for Cr(VI) removal by combining the advantages of high adsorption capacity of PmPD and easy reclamation of BC. Through monomer (mPD) pre-adsorption on BC, the stable hybrid structure of PmPD nanoparticles functionalization on BC fibril was successfully realized by in-situ oxidative polymerization of adsorbed mPD. The morphology and structure of the adsorbents were analyzed by SEM, TEM, XRD, FTIR, and XPS techniques. The interaction between BC and PmPD and adsorption mechanism were also analyzed. The optimized BC/PmPD has Langmuir Cr(VI) adsorption capacity of 434.78 mg/g, much higher than many reported adsorbents. The Cr(VI) adsorption on BC/PmPD was ascribed to the Cr(VI) adsorption on protonated NH and NH2 groups and the redox reaction of Cr(VI) to Cr(III) by the reduction of amine, followed by Cr(III) chelation on imino groups of PmPD. The recycling test indicated that the BC/PmPD has good regeneration and reusability capacity with its fast-reversible macroscopic assembly and disassembly features, and high stabilization of PmPD on BC. Findings in the present study demonstrated that the BC/PmPD can be considered as a promising adsorbent for Cr(VI) removal due to its high adsorption capacity, efficient reclamation, good regeneration performance.

A plant community is an open thermodynamic system. In accordance with the first and second laws of thermodynamics, the total internal energy U of a plant community before reaching equilibrium will increase under natural conditions because of solar energy intake and nutrient uptake. As state functions of a thermodynamic system, enthalpy H, entropy S and Gibbs free energy G are related to U by G + TS = H = U + PV. Increase in U will lead to increases in H, S and G since given volume V and temperature T or pressure P, dG + TdS = dH = dU > 0. The experimental data collected from the plant communities restored on a manganese tailing site confirmed the potential trend of increase in H, S and G of the plant communities with increase in their biomass quantity and biodiversity. The traditional criterion “ΔG

Overpressure blast-wave induced brain injury (OBI) and its long-term neurological outcome pose significant concerns for military personnel. Our aim is to investigate the mechanism of injury due to OBI.Rats were divided into 3 groups: (1) Control, (2) OBI (exposed 30psi peak pressure, 2-2.5ms), (3) Repeated OBI (r-OBI) (three exposures over one-week period). Lung and brain (cortex and cerebellum) tissues were collected at 24h post injury.The neurological examination score was worse in OBI and r-OBI (4.2±0.6 and 3.7±0.5, respectively) versus controls (0.7±0.2). A significant positive correlation between lung and brain edema was found. Malondialdehyde (index for lipid peroxidation), significantly increased in OBI and r-OBI groups in cortex (p0.05) and cerebellum (p0.01-0.001). The glutathione (endogenous antioxidant) level decreased in cortex (p0.01) and cerebellum (p0.05) of r-OBI group when compared with the controls. Myeloperoxidase activity indicating neutrophil infiltration, was significantly (p0.01-0.05) elevated in r-OBI. Additionally, tissue thromboplastin activity, a coagulation marker, was elevated, indicating a tendency to bleed. NGF and NF-κB proteins along with Iba-1 and GFAP immunoreactivity significantly augmented in the frontal cortex demonstrating microglial activation. Serum biomarkers of injury, NSE, TNF-alpha and leptin, were also elevated.OBI triggers both inflammation and oxidative injury in the brain. This data in conjunction with our previous observations suggests that OBI triggers a cascade of events beginning with impaired cerebral vascular function leading to ischemia and chronic neurological consequences.

The normal cellular prion protein (PrPC) is a sialoglycoprotein with a glycophosphatidylinositol anchor and expressed in highest levels within the CNS particularly at neuronal synapses. This membrane-bound protein is involved with many cell functions including cell signaling and neuroprotection. Calpains are calcium-activated cysteine proteases that typically undergo controlled activation. PrPC is a calpain substrate and is neurotoxic if it undergoes aberrant processing with cytosol accumulation. Following traumatic brain injury (TBI), there is an abnormal influx of Ca+2 and overactivation of calpains resulting in neuronal dysfunction and cell death. We investigated whether PrPC expression and calpain activity have an effect on, or are affected by, TBI. PrPC expression in the hippocampus, cortex and cerebellum of WT and Tga20 (PrPC overexpression) mice were unchanged after closed head injury (CHI). Further, PrPC in WT and Tga20 mice was resistant to TBI-induced calpain proteolysis. CHI-induced calpain activation resulted in breakdown products (BDPs) of αII-spectrin (SBDPs) and GFAP (GBDP-44K) in all brain regions and mouse lines. CHI caused significant increases in SBDP145, GFAP and GBDP-44K when compared to sham. With few exceptions, the calpain inhibitor, SNJ-1945, reduced SBDP145 and GBDP-44K levels. Behavioral studies suggested that PrPC and calpain independently affect learning and memory. Overall, we conclude that: (i) there is SNJ-1945-sensitive calpain activation in both neuron and glial cells following CHI, (ii) closed head trauma is not affected by, nor does it have an influence on, PrPC expression, and (iii) PrPC expression plays a minor role, if any, in CHI-induced calpain activation in vivo.

It is a challenge to simultaneously treat the combined pollutants of chromium(VI) (Cr(VI)) and organics (such as phenol) in wastewater. Here, a stable and efficient redox system based on FeS2 sulfidated zero valent iron (FeS2/Fe0) and persulfate (PS) was developed to synchronously remove Cr(VI) and phenol. 100% of phenol (10 mg/L) was oxidized in 10 min and Cr(VI) (20 mg/L) was completely reduced to Cr(III) in 90 min in the FeS2/Fe0+PS system with a pH range of 3.0–9.0, respectively. phenol was selectively oxidized without re-oxidizing Cr(III) in such system. The surface-bound Fe2+ was the major reactive species to synchronously reduce Cr(VI) and oxidize phenol. The mechanisms were elucidated that the phenol degradation was accelerated by the generated Cr(III) complexing with its products, and that SO42−, whose production speed was accelerated by the PS activation to oxidize phenol and FeS2, was conductive to corrode Fe0 to regenerate the surface-bound Fe2+ for reducing Cr(VI) and oxidizing phenol. It is potential to develop a high-performance and large-scaled FeS2/Fe0-based redox platform to remediate the complex pollution of Cr(VI) and organics.

Anionic Cr(VI) and cationic heavy metals generally co-exist in industrial effluents and threaten the public health. Zero-valent iron (ZVI) particles tent to passivate rapidly, which results in a gradual drop in its reactivity. In this work, a strategy of “in-situ synthesized” iron-based bimetal was first developed to stimulate the self-activation of passivated ZVI. During this process, ZVI-loaded hydroxyapatite (ZVI/HAP) was prepared to enhance the affinity for co-existing Cu2+, which promoted the in-situ Cu0 deposition on ZVI/HAP to form a Fe–Cu bimetal. The deposited Cu0 significantly decreased the activation energy (Ea) of Cr(VI) reduction by 24.9%, and its corresponding Cr(VI) removal (96.53%) was much higher that of single Cr(VI) system (68.67%) within 9 h. More importantly, the removal of Cr(VI) and Cu2+ were synchronously achieved. Systematical electrochemical characterizations were first introduced to explore the galvanic behaviors of iron-based bimetal. The charge transfer resistance and the negative open circuit potential of ZVI/HAP significantly decreased with the Cu0 deposition, thereby accelerating the electron transfer from Fe0 to Cu2+. The enhanced electron transfer further facilitated the Fe(II) release to promote Cr(VI) reduction. This “in-situ synthesized” iron-based bimetal strategy provides a novel pattern for ZVI activation and exhibits practical application in remediation of combined contaminant.

Two-dimensional metal carbides or nitrides (MXenes) demonstrate various excellent properties; however, their poor permeability precludes their application in water treatment. In this study, Ti3C2Tx MXene/nZVI/fungal hyphae nanofiber hybrid membranes (MXene/nZVI@FH) were prepared by chemical-intensive precipitation method for the robust capture of Be(II) from a beryllium-ammonia complexing solution. Interestingly, the MXene/nZVI@FH membrane showed favorable water permeability (6.10 × 10−15 m2), which was approximately 301 times higher than that of a pure Ti3C2Tx membrane, and 99.8% Be(II) was captured from the Be(NH2)2 complexing solution with an extremely low concentration (19.85 ppm). Specifically, the maximum Be(II) adsorption capacity of MXene/nZVI@FH was calculated to be 95.20 mg/g from the Be(NH2)2 complexing solution at pH 5.0 and 35 °C. Various characterization results (e.g., SEM, FTIR, XRD, VSM and XPS) suggested that Be(II) prefers to coordinate with surface oxygen groups bonded to the MXene nanosheets by forming BeO and BeO22− bidentate inner-sphere complexes. Furthermore, due to its reticular sandwiched structure, MXene/nZVI@FH could be easily activated and reused by leaching with 0.1 M HCl solution. Thus, it is a promising hybrid membrane for the removal and recovery of Be(II) from a Be(NH2)2 complexing solution.

Cr(VI) contamination is a worldwide environmental problem, and bacterial reduction is considered a promising method for Cr(VI) remediation. In the present study, the role of extracellular polymeric substances (EPS) in the remediation of Cr(VI) by Pannonibacter phragmitetus BB was thoroughly studied. The results showed that the secretion of protein-fraction EPS by P. phragmitetus BB was significantly induced by Cr(VI), which increased from 382.70 to 1483.29 μg/mL with the increase of the initial Cr(VI) concentration (48–60 h). The polysaccharide content in slime EPS (SL-EPS) and loosely bound EPS (LB-EPS) increased gradually with time when the Cr(VI) concentration increased from 0 to 200 mg/L, with the highest polysaccharide content being higher than 2500 μg/mL. In contrast, the change in polysaccharides in tightly bound EPS (TB-EPS) was insignificant (p

Chemical reduction of Cr(VI) to Cr(III) by reductive materials is the most widely used technology for the remediation of Cr(VI)-contaminated soil due to its high efficiency, adaptability and low cost. This paper reviews chromium chemistry and the materials that can effectively reduce Cr(VI) to Cr(III) for the remediation of Cr(VI)-contaminated soil, namely iron-bearing reductants, sulfur-based compounds and organic amendments. Moreover, we discuss the corresponding mechanisms involved in the process of immobilization of Cr(VI) in polluted soil, and emphasize the relationship between the materials remediation performance and soil environmental conditions. Besides, perspectives on the potential future researches of novel materials design and technological development in the remediation of Cr(VI) contaminated soil are also put forward.

Electrostatic and complexation effects have been considered as the primary adsorption mechanisms for defluorination using aluminum based materials, while the effect of ion exchange between anions and fluorine ion has been mostly ignored, although synthesized alumina materials usually contain a large amount of anions, such as SO42−, NO3−, and Cl−. In this study, the effect of anions exchanges and its key role on defluorination were systematically investigated for adsorption by aluminas loaded with various typical anions (SO42−, NO3− and Cl−). Experimental results showed that SO42-- loading alumina had the best defluorination performance (94.5 mg/g), much higher than NO3− (45.0 mg/g) and Cl− (19.1 mg/g). The contribution ratio of ion exchange between SO42− and F− was as high as 20–60% in all potential defluorination mechanisms. By using Density Functional Theory calculation, the detailed mechanism revealed that the ion exchange process was mainly driven by the tridentate chelation of SO42− which reduced the exchange energy ( Δ F − − SO 4 2 − 4.8 eV). Our study clearly demonstrated that ion exchange between SO42− and F− is a critical mechanism in defluorination using aluminum-based materials and provides a potential alternative method to enhance the adsorption performance of modified alumina.

Removal of aromatic contaminants (ACs) in waters by sulfate radical anion (SO4 −) based advanced oxidation technology has been extensively studied. Three main mechanisms have frequently been used to account for the first step of radical oxidation of ACs: radical adduct formation, hydrogen atom abstraction, and single electron transfer (SET), among which the SET pathway is the least understood. In this study, we investigated the first step of SET reactions for 76 ACs with SO4 −. The result shows that the Gibbs free energy ( Δ G SET ∘ ) of the reaction increases with a decrease of the electron donating character of the substituents on the ACs. The trend was then quantitatively corroborated by a Hammett type plot, indicating that the electrostatic interaction is the driving force for the SET pathway. Further, we compared the calculated second-order rate constants (kSET) for the ACs via the SET pathway with their experimental k values, and proposed two fundamental SET reaction mechanisms based on the identified intermediates. The thermodynamic and kinetic results obtained advance the mechanistic understanding of the SET pathway of radical and non-radical bimolecular reactions, and shed light on the applicability of SO4 − in ACs removal during water treatment processes.

To explore how heavy metal contamination in Chromite Ore Processing Residue (COPR) disposal sites determine the dissimilarities of indigenous microbial communities, 16S rRNA gene MiSeq sequencing and advanced statistical methods were applied. 13 soil samples were collected from three COPR disposal sites in Mouding of southwestern, Shangnan of northwestern and Yima of central China. The results of analyses of variance (ANOVA), similarities (ANOSIM), and non-metric multidimensional scaling (NMDS) showed that the structural diversity of the microbial communities in the samples with high total chromium (Cr) content (more than 300 mg kg−1; High group) were significantly lesser than in the Low group (less than 90 mg kg−1) regardless of their geographical distribution. But their diversity had virtually rehabilitated under the pressures of long-term metal contamination. Furthermore, the similarity percentage (SIMPER) analysis indicated that the major dissimilarity contributors Micrococcaceae, Delftia, and Streptophyta, possibly having Cr(VI)-resistant and/or Cr(VI)-reducing capability, were dominant in the High group, while Ramlibacter and Gemmatimonas with potential resistances to other heavy metals were prevalent in the Low group. In addition, the multivariate regression tree (MRT), aggregated boosted tree (ABT), and Mantel test revealed that total Cr content affiliated with Cr(VI) was the principal factor shaping the dissimilarities between the soil microbial communities in the COPR sites. Our findings provide a deep insight of the influence of these heavy metals on the microbial communities in the COPR disposal sites and will facilitate bioremediation on such site.