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The reliability and accuracy of suggested online approach for speciation analysis of mercury was well proved by confirmatory experiments.Dissolved organic matter (DOM) play key roles in the biotransformation of arsenic in groundwater systems. However, the effects of different types of DOM on arsenic biogeochemistry remain poorly understood. In this study, four typical DOM compounds (acetate, lactate, AQS and humic acid) were amended to high As aquifer sediments to investigate their effects on arsenic/iron biotransformation and microbial community response. Results demonstrated that different DOM drove different microbial community shifts and then enhanced microbially-mediated arsenic release and iron reduction. With labile DOM (acetate and lactate) amendment, the abundance of putative dissimilatory iron and sulfate reducers Desulfomicrobium and Clostridium sensu stricto increased within the first week, and subsequently the anaerobic fermentative bacterial genus Acetobacterium and arsenate/sulfate-reducing bacterial genus Fusibacter became predominant. In contrast, recalcitrant DOM (AQS and humic acid) mainly stimulated the abundances of sulfur compounds respiratory genus Desulfomicrobium and fermentative bacterial genus Alkalibacter in the whole incubation. Accompanied with the microbial community structure and function shifts, dissolved organic carbon concentration and oxidation-reduction potential changed and the arsenic/iron reduction increased, which resulted in the enhanced arsenic mobilization. Collectively, the present study linked DOM type to microbial community structure and explored the potential roles of different DOM on arsenic biotransformation in aquifers.In this study, the synergistic adsorption behavior of palladium [Pd(II)], molybdenum [Mo(VI)], and zirconium [Zr(IV)] in simulated high-level liquid waste was systematically investigated based on various factors, such as the contact time, concentration of nitric acid, adsorption amount, and temperature using a silica-based adsorbent impregnated with N,N’-dimethyl-N,N’-di-n-hexyl-thiodiglycolamide (Crea) and 2, 2′, 2′ -nitrilotris[N,N-bis(2-ethylhexyl)acetamide] (TAMIA-EH). The adsorption rates of Pd(II), Mo(VI), and Zr(IV) in this synergistic adsorption system were high; thus, equilibrium states could be obtained in only 1 h with high uptake percentages of more than 90%. The adsorption abilities of Pd(II), Mo(VI), and Zr(IV) were only slightly affected by variation in the concentration of nitric acid in the range of 0.1-5 M and solution temperature in the range of 288-313 K. Selective stripping of the adsorbed Re(VII), Pd(II), Zr(IV), and Mo(VI) was successfully achieved under elution with 5 M HNO3, 0.2 M Tu (pH 1), 50 mM DTPA (pH 2), and 50 mM DTPA dissolved in 0.5 M Na2CO3 (pH 11) solutions using the chromatography method. In addition, the adsorption performance in solid-state was studied using the particle-induced X-ray emission (PIXE) method; the obtained results were in good agreement with the results obtained via column separation.Polyethylene (PE) is one of the most highly consumed petroleum-based polymers and its accumulation as waste causes environmental pollution. In this sense, the use of microorganisms and their enzymes represents the most ecofriendly and effective decontamination approach. In this work, molecular docking simulation for catalytic enzyme degradation of PE was carried out using individual enzymes laccase (Lac), manganese peroxidase (MnP), lignin peroxidase (LiP) and unspecific peroxygenase (UnP). PE-binding energy, PE-binding affinity and dimensions of PE-binding sites in the enzyme cavity were calculated in each case. Four hypothetical PE biodegradation pathways were proposed using individual enzymes, and one pathway was proposed using a synergic enzyme combination. These results show that in nature, enzymes act in a synergic manner, using their specific features to undertake an extraordinarily effective sequential catalytic process for organopollutants degradation. MEK162 ic50 In this process, Lac (oxidase) is crucial to provide hydrogen peroxide to the medium to ensure pollutant breakdown. UnP is a versatile enzyme that offers a promising practical application for the degradation of PE and other pollutants due to its cavity features. This is the first in silico report of PE enzymatic degradation, showing the mode of interaction of PE with enzymes as well as the degradation mechanism.Two-dimensional (2D) transition metal dichalcogenides (TMDs) hold great promise for room temperature (RT) NO2 sensors. However, the exposure of the edges of TMDs with high adsorption capability and electronic activity remains a great obstacle to achieve high sensor sensitivity. Herein, we demonstrate a high-performance RT NO2 gas sensor based on WS2 nanosheets/carbon nanofibers (CNFs) composite with abundant intentionally exposed WS2 edges. Few-layer WS2 nanosheets are anchored on CNFs through a hydrothermal process. The approach permits to achieve a coating presenting an optimized active surface area and accessibility of the sensing layers. The exposure of WS2 edges remarkably improves the sensing properties. Consequently, the WS2@CNFs composite exhibits excellent selectivity to NO2 at RT with improved response and much lower detection limit in comparison to the WS2 and CNFs counterparts. Density functional theory (DFT) calculations verify a surprisingly strong NO2 adsorption on WS2 edge sites (adsorption energy 3.40 eV) with a partial charge transfer of 0.394e, while a week adsorption on the basal surface of WS2 (adsorption energy 0.25 eV) with a partial charge transfer of 0.171e. The strategy proposed herein will be instructive to the design of efficient material structures for low-power NO2 sensors with optimized performances.Aquatic foods are important sources of chlorinated paraffins (CPs) to humans. Farmed crabs are bottom-dwelling aquatic animals, and can accumulate CPs through food and aquatic environment. However, limited information is available on CPs concentrations in and sources to farmed crabs. In this study, short-chain CPs (SCCPs) and medium-chain CPs (MCCPs) concentrations in 59 samples from the farmed crab food web (crab, crab feed, and aquaculture environment) were determined. The samples were from 17 crab farms in Anhui Province, Jiangxi Province, and Shanghai, in China. The SCCPs and MCCPs concentrations in the crab samples were 82-1760 and not detected-680 ng/g lipid weight, respectively. The dominant SCCPs and MCCPs in the crab samples were C10Cl6-7 and C14Cl7-8, respectively. The SCCPs concentrations in the crab food web samples were higher than the MCCPs concentrations. SCCPs contamination of the crab food web samples was not directly related to CPs product use. The main factors affecting SCCPs concentrations in the crab samples were different for different crab farms.