Chitosan-derived N-doped carbon supported Cu/Fe co-doped MoS nanoparticles as peroxymonosulfate activator for efficient dyes degradation.

Peroxymonosulfate (PMS), which is dominated by free radical (SO) pathway, has a good removal effect on organic pollutants in complex water matrices. In this article, a new catalyst (CFM@NC) was synthesized by hydrothermal carbonization method with chitosan (CS) as N and C precursors, and used to activate PMS to degrade dye wastewater. CFM@NC/PMS system can degrade 50 mg·L rhodamine B by 99.

Chitosan derived N-doped carbon anchored CoO-doped MoS nanosheets as an efficient peroxymonosulfate activator for degradation of dyes.

Peroxymonosulfate (PMS), which is dominated by non-free radical pathway, has a good removal effect on organic pollutants in complex water matrices. In this article, a biodegradable cobalt-based catalyst (CoO/MoS@NCS) was synthesized by a simple hydrothermal method with chitosan (CS) as nitrogen‑carbon precursor and doped with Cobaltic‑cobaltous oxide (CoO) and Molybdenum disulfide (MoS), and was used to activate PMS to degrade dye wastewater. Electrochemical tests showed that CoO/MoS@NCS exhibited higher current density and cycling area than MoS@NCS and MoS.

Preparation of Ti/SnO-SbO-La Electrode with TiO Nanotubes Intermediate Layer and the Electrochemical Oxidation Performance of Rhodamine B.

A La-doped Ti/SnO-SbO electrode with TiO-NTs intermediate layer (Ti/TiO-NTs/SnO-SbO-La) was created via the electrodeposition technique. The physicochemical and electrochemical properties of the electrode were analyzed through FESEM, XRD, XPS, CV, and LSV electrochemical tests. The results showed that TiO-NTs were tightly packed on the surface of Ti substrate, thus improving the binding force of the SnO-SbO-La coating, offering greater specific surface area, more active spots, higher current response, and longer lifespan for the degradation of rhodamine B.

Preparation of La-doped Ti/SnO-SbO anode and its electrochemical oxidation performance of rhodamine B.

In this paper, La-doped Ti/SnO-SbO electrode was prepared by electrodeposition and used for electrochemical degradation of rhodamine B. The optimum preparation conditions of the electrode were optimized as deposition time of 15 min and calcination at 500 ℃ for 2 h. The water treatment conditions were selected as initial pH 3.

Toxicological effects and underlying mechanisms of chlorination-derived metformin byproducts in Escherichia coli.

Chlorination-derived byproducts of the emerging contaminant metformin, such as (3E)-3-(chloroimino)-N,N-dimethyl-3H-1,2,4-triazol-5-amine (3,3-CDTA) and N-cyano-N,N-dimethylcarbaminmidic chloride (NCDC), occur in global waters and are toxic to organisms, from bacteria to mice. However, the mechanisms underlying their toxicity remain unknown. Here, we explored the toxicological effects and potential molecular mechanisms of 3,3-CDTA and NCDC at milligram concentrations, using Escherichia coli as a model organism.

Metformin Contamination in Global Waters: Biotic and Abiotic Transformation, Byproduct Generation and Toxicity, and Evaluation as a Pharmaceutical Indicator.

Metformin is the first-line antidiabetic drug and one of the most prescribed medications worldwide. Because of its ubiquitous occurrence in global waters and demonstrated ecotoxicity, metformin, as with other pharmaceuticals, has become a concerning emerging contaminant. Metformin is subject to transformation, producing numerous problematic transformation byproducts (TPs).

Prevalence, production, and ecotoxicity of chlorination-derived metformin byproducts in Chinese urban water systems.

The widely used antidiabetic drug metformin has become an emerging contaminant of water systems. In a prior study, we demonstrated the marked mammalian toxicity of the disinfection-derived byproducts (DBPs) Y (yellow, CHClN) and C (colorless, CHClN), and here assess the distribution, formation, and ecotoxicity of these in Chinese urban water systems. A national tap water assessment showed that metformin and C concentrations were higher in large, dense urban areas and surface water sources than in sparsely populated areas and groundwater sources.

Metformin chlorination byproducts in drinking water exhibit marked toxicities of a potential health concern.

Metformin (MET), a worldwide used drug for type 2 diabetes, has been found with the largest amount by weight among all drugs in aquatic environment, including the drinking water systems where this emerging micropollutant is inevitably transformed during chlorination process. Whether MET chlorination byproducts Y (CHClN) and C (CHClN) exist in drinking water remains unknown. Although MET has health-promoting properties, whether or how its chlorination byproducts affect health is still uncharacterized.

Improved matrix pooling.

Pooled testing is useful to identify positive specimens for large-scale screening. Matrix pooling is one of the commonly used algorithms. In this work, we investigate the properties of matrix pooling and reveal that the efficiency of matrix pooling is related with the magnitude of overlapping among groups.

Degradation of N-nitrosodimethylamine (NDMA) and its precursor dimethylamine (DMA) in mineral micropores induced by microwave irradiation.

Removal of N-nitrosodimethylamine (NDMA) in drinking water treatment poses a significant technical challenge due to its small molecular size, high polarity and water solubility, and poor biodegradability. Degradation of NDMA and its precursor, dimethylamine (DMA), was investigated by adsorbing them from aqueous solution using porous mineral sorbents, followed by destruction under microwave irradiation. Among the mineral sorbents evaluated, dealuminated ZSM-5 exhibited the highest sorption capacities for NDMA and DMA, which decreased with the density of surface cations present in the micropores.