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The efficient and green removal technology of refractory organics such as atrazine in water has been an important topic of research in water treatment. A novel membrane composite biocatalyst Lac-HBT-Pd/BC as prepared for the first time by co-immobilizing laccase, mediator 1-hydroxybenzotriazole (HBT) and metal Pd on functionalized bacterial cellulose (BC) to investigate the removal of atrazine and degradation of its intermediates under mild ambient conditions. It was found that atrazine could be completely degraded in 5 h by the catalysis of Lac-HBT-Pd/BC, and the removal rate of degradation intermediates from atrazine was about 85% after continuous catalysis, which achieved deep degradation of atrazine. The effect of electrochemical activity and radical stability of the membrane composite biocatalysts loaded with Pd was investigated. The possible degradation pathways were proposed by identifying and analyzing the deep degradation products of atrazine. The Lac-HBT-Pd/BC demonstrated deep degradation of atrazine and favorable reusability as well as considerable adaptability to various water qualities. This work provides an important reference for preparing new kinds of biocatalysts to degrade refractory organic pollutants in water. [Display omitted] • The co-immobilized laccase-1-HBT-Pd membrane biocatalyst was prepared. • The membrane biocatalyst can degrade effectively and deeply atrazine in water. • Atrazine could be completely degraded in 5 h by the membrane biocatalyst. • The removal rate of degradation intermediates from atrazine was up to 85%. [ABSTRACT FROM AUTHOR]

The continuous growth of e-waste necessitates an efficient method to recover their metal contents to improve their recycling rate. The successful recovery of the metallic component from Waste Electrical and Electronic Equipment (WEEE) can generate great economic benefits to incentivize the industrial recycling effort. In this study, we report the use of slurry electrolysis (SE) in pH-neutral ethylene glycol (EG) electrolyte to extract and recover the metallic component from waste printed circuit broad (WPCB) powder. The system operates at room temperature and atmospheric pressure, and the electrolyte can be recycled multiple times with no signs of chemical degradation. The EG electrolyte system can oxidize the metallic component without triggering anodic gas evolution, which allowed us to incorporate a reticulated vitreous carbon (RVC) foam anode to maximize the capture and oxidation of the metal content. The system demonstrated up to 99.1% Faraday efficiency for the cathodic metal deposition and could recover Cu from the WPCB powder in a selective manner of 59.7% in the presence of 12 other metals. The SE reaction system was also scalable and displayed no compromises on the Cu recovery selectivity. With the ability to leach and recover metallic content from WPCB in a mild and chemically benign condition, the SE system displayed much promise to be adapted for industrial-scale metal recovery from WPCB. [Display omitted] • SE enables the extraction and recovery of metals from WPCB powder at room temp and atmospheric pressure. • High Faradaic efficiency of 99.1%; nearly all electrons were spent on metal recovery. • Highly selective towards Cu with a selectivity of 59.7% from 12 other metals found in the WPCB. • Reaction is scalable and solvent is recyclable. HPLC analysis confirmed the electrolyte is stable. [ABSTRACT FROM AUTHOR]

Environmental impacts of carbon nanotubes (CNTs) arise both from the characteristics of CNTs as well as from their sorbed contaminants from aquatic environments. In this work, we employed pristine, carboxyl-, hydroxyl- and amino-functionalized multi-walled CNTs and pristine single-walled CNTs to quantify and compare their impacts on aquatic microbial communities in the absence and presence of Cu or Cr. Aliquots of samples were set up to 10 and 40 days for culture-dependent analyses, namely, quantitative real-time polymerase chain reaction and denaturing gradient gel electrophoresis. Results revealed that the presence of CNTs or the mixture of CNTs and metals transiently affected microbial communities, and toxicity of CNTs was enhanced with the addition of metals. Meanwhile, functionalized CNTs exhibited stronger toxicity. The major impacts were observed after 10 days of exposure, but the microbial community could recover at 40 days to some extent. Though microbial communities recovered, total microbial numbers continued to decrease with contact time. Analysis of sequence cloned 16S rDNA indicated that Bacillus sp. and Acidithiobacillus sp. were the dominant taxa. Overall, CNTs would have more serious risk to an ecosystem in the presence of metals. [ABSTRACT FROM AUTHOR]

Silica nanoparticles (SiNPs) have drawn considerable attention due to their environmental health effects, while enhanced understanding of metabolic disorders has provided insight into related diseases. To investigate the impacts of SiNPs exposure on reproduction and reveal their pathogenic mechanisms, this study was designed and conducted from a metabolic perspective. First, fluorescein isothiocyanate (FITC)-SiNPs were chemically synthesized and applied to track SiNPs in vitro and in vivo. Next, 30 pregnant mice were intratracheally instilled with 1.25 mg of SiNPs/mouse, then sacrificed 24 h post-treatment. We found that SiNPs penetrated the trophoblast membrane, triggering apoptosis and inhibiting cell proliferation, invasion, and tube formation in a dose-dependent manner. Mechanistically, SiNPs dysregulated phosphofructokinase (Pfkl) and fructose-bisphosphatase 2 (Fbp2) and induced glucose depletion and pyruvate accumulation via the pentose phosphate pathway. Besides, the downregulation of caspase-3 suggested a causal relationship between pyruvate accumulation, pentose phosphate pathway activation, and cell apoptosis. Pfkl and Fbp2 was also dysregulated in vivo , and the uterine inflammation aggravated in a time-dependent manner. In conclusion, SiNPs triggered acute cytotoxicity and uterine inflammation by inducing glucose depletion and pyruvate overload in trophoblasts, which were mediated in part by Pfkl and Fbp2 via the pentose phosphate pathway. [Display omitted] ● SiNP was successfully conjugated with FITC based on the Stöber method. ● SiNP could penetrate the membrane of trophoblast and induce cell dysfunction in vitro. ● SiNP induced glucose depletion and pyruvate overload in trophoblast. ● Accumulation of SiNP in the uterus triggered acute inflammation in vivo. ● The SiNP-induced reproductive toxicity was mediated via the pentose phosphate pathway. [ABSTRACT FROM AUTHOR]

• Indole can be effectively degraded by MFC with the modified carbon felt anode. • The modified anode provided suitable environment for electroactive bacteria growth. • 90.3 % of 200 mg L−1 indole was degraded by MFC after 120 h operation. • The power density of 3184.4 mW·m−2 was achieved for MFC loading the modified anode. Indole is a high-toxic refractory nitrogen-containing compound that could cause serious harm to the human and ecosystem. It has been a challenge to develop economical and efficient technology for degrading indole. Microbial fuel cell (MFC) has great potential in the removal of organic pollutants utilizing microorganisms as catalysts to degrade organic matter into the nutrients. Herein, a novel anode of Fe 2 O 3 -polyaniline-dopamine hybrid composite modified carbon felt (Fe 2 O 3 -PDHC/CF) was prepared by electrochemical deposition. The degradation efficiency of indole by the MFC loading Fe 2 O 3 -PDHC/CF anode was up to 90.3 % in 120 h operation, while that of the MFC loading CF anode was only 44.0 %. The maximum power density of the MFC loading Fe 2 O 3 -PDHC/CF anode was 3184.4 mW·m−2, increasing 113 % compared to the MFC loading CF anode. The superior performances of the MFC with Fe 2 O 3 -PDHC surface-modified anode owned to the synergistic effect of high conductive Fe 2 O 3 and admirably biocompatible polyaniline-dopamine. MFC with the Fe 2 O 3 -PDHC/CF anode could produce considerable electricity and effectively degrade indole in water, which demonstrated a practical approach for the efficient degradation of refractory organic compounds in wastewater. [ABSTRACT FROM AUTHOR]