Base-catalyzed hydrolysis mechanism of polychlorinated dibenzo-p-dioxins based on quantitative structure-activity relationship.

Polychlorinated dibenzo-p-dioxins (PCDDs) are persistent organic pollutants that pose considerable threats to ecological and human health owing to their high toxicity potential. Understanding the mechanisms for underlying the base-catalyzed hydrolysis of PCDDs in aquatic environments is essential for assessing their environmental behaviour and ecological risks. Herein, we combined quantitative structure-activity relationship (QSAR) models with density functional theory calculations to analyse the base-catalyzed hydrolysis mechanisms of PCDDs.

Selective oxidation of ammonium to dinitrogen by a novel catalytic ozonation system: Regulating the N selectivity by sulfite.

The selective oxidation of NH-N into dinitrogen (N) is still a challenge. Currently, traditional advanced oxidation processes often involve in the chlorine free radicals to increase the selectivity of NH-N oxidation products towards N but is usually accompanied by the production of many toxic disinfection by-product. Herein, we reported a novel catalytic ozonation system (UV/O/MgO/NaSO) for selective NH-N oxidation based on the reducing capability and photochemical properties of NaSO.

Transformation behavior and toxicity assessment of beaytlmethodeyammonNium chbride (BAC-12) disinfectant during hospital wastewater treatment.

This work focused on the transformation behavior of the emerging beaytlmethodeyammonium chbride (BAC-12) disinfectant existed in the treatment of medical sewage during its disinfection treatment. The degradation ability of ozone (O) to BAC-12 was the best, followed by UV/NaOCl, UV, and NaOCl. The enhancement of BAC-12 in UV/NaOCl system is caused by the combined effect of UV photolysis, reactive chlorine species (RCS), and •OH.

A critical review on the symbiotic effect of bacteria and microalgae on treatment of sewage with biofertilizer production.

Wastes like sewage, kitchen and industrial are the major sources of environmental pollution and health hazards. Sewage contains 99.9% water and 0.

Modeling the Global Impact of Chlorine Chemistry on Secondary Organic Aerosols.

Simulation of secondary organic aerosol (SOA) in models has been an uncertain component in determining the impacts of atmospheric aerosols on air quality and climate. Recent studies have shown that reactive chlorine can rapidly oxidize volatile organic compounds (VOCs), trigger SOA formation, and alter other oxidants, thus having a potentially significant effect on SOA, which has not been thoroughly investigated at the global scale. Here, we developed a chlorine-SOA simulation within a global chemical transport model along with updated anthropogenic continental chlorine emissions.

Optimization of Cl and heavy metal removal during heat treatment of municipal solid waste incineration fly ash and municipal sludge after co-washing.

Heat treatment, known for its detoxification and volume reduction characteristics, is a promising technology for the management of municipal solid waste incineration fly ash (MFA) and municipal sludge (MS). This paper uses the solid residue from MFA and MS after co-washing as the raw material to study the melting properties, phase transformations, changes in Cl content, heavy metal removal efficiency, and leaching toxicity. The results indicated that co-processing of MFA and MS can effectively reduce the melting temperature.

Optimization of a solid-phase extraction step by experimental design for application to SPE-GC-ECD analysis of four bromobenzoquinones and 2,4,6-tribromophenol in chlorinated seawater.

Bromobenzoquinones and 2,4,6-tribromophenol belong to disinfection or chlorination by-products than can be formed in bromide-rich waters during chlorination or chloramination. Due to their high toxicities, sensitive and cost-effective analytical methods are necessary to detect and quantify them in various environmental matrices. A determination method of 2,5-dibromo-1,4-benzoquinone, 2,6-dibromo-3,5-dimethyl-1,4-benzoquinone, 2,6-dibromo-3-chloro-5-methyl-1,4-benzoquinone, 2,3,5,6-tetrabromo-1,4-benzoquinone and, 2,4,6-tribromophenol was developed using solid-phase extraction and electron capture detector-gas chromatography separation and detection (SPE-GC-ECD).

Experimental study and mechanism analysis of high-efficiency adsorption of PCDD/Fs on N-doped hierarchical porous biochar.

Adsorption removal of PCDD/Fs from flue gas is one of the important technologies for reducing environmental PCDD/Fs emissions. However, due to the lack of systematic research on the adsorption mechanism of PCDD/Fs, commercial activated carbon (AC) with a single pore size distribution and lack of surface functional groups has poor adsorption and removal efficiency for PCDD/Fs. Therefore, this study first used corncob as a raw material and prepared N-doped hierarchical porous biochar (NHPB) using a one-step activation method for efficient removal of PCDD/Fs.

Click dechlorination of halogen-containing hazardous plastics towards recyclable vitrimers.

Amid the ongoing Global Plastics Treaty, high-quality circulation of halogen-containing plastics in an environmentally sound manner is a globally pressing issue. Current chemical dechlorination methods are limited by their inability to recycle PVC at the long-chain carbon level and the persistence of eco-toxic organochlorine byproducts. Herein, we propose a click dechlorination strategy for transforming waste PVC into valuable vitrimers via a one-step cascade thiol-ene click reaction and dynamic polymerization.

Role of Clay Minerals in Natural Media Self-Regeneration from Organic Pollution-Prospects for Nature-Inspired Water Treatments.

Pollution from organic molecules is a major environmental issue that needs to be addressed because of the negative impacts of both the harmfulness of the molecule structures and the toxicity that can spread through natural media. This is mainly due to their unavoidable partial oxidation under exposure to air and solar radiation into diverse derivatives. Even when insoluble, the latter can be dispersed in aqueous media through solvatation and/or complexation with soluble species.

Magnesium Bicarbonate-Walnut Shell Dual-Template Synthesis of Multifunctional Layered Porous Carbon for Enhanced Adsorption of Aqueous Chlorinated Organic Compounds.

Chloride ions readily react with organic matter and other ions, resulting in the formation of disinfection by-products (DBPs) that exhibit heightened levels of toxicity, carcinogenicity, and mutagenicity. This study creatively employed waste walnut shells as self-templates and low-cost magnesium bicarbonate as a rigid template to successfully synthesize multifunctional porous carbon derived from walnut shells. Employing a series of characterization techniques, it was ascertained that the porous carbon material (WSC/Mg) synthesized via the dual-template method exhibited a distinct layered microscopic surface structure, with a predominance of C and O elements on the surface.

Concerning Toxic Byproducts and Full-Scale UV/Chlorine Advanced Oxidation Water Treatment.

This work investigated byproduct formation and genotoxicity and cytotoxicity at four facilities using UV/chlorine advanced oxidation for potable reuse or drinking water treatment. In arguably the most common application of UV/chlorine, treating reverse osmosis permeate for potable reuse, organic byproduct formation was always either not detected or well-below typical drinking water levels. At a groundwater-source drinking water treatment plant, the trihalomethanes and haloacetic acids each increased by up to 12 μg/L through the UV reactor and 40 μg/L during secondary disinfection, but the final concentrations remained low relative to regulatory limits.

Peracetic acid-based electrochemical treatment of sulfamethoxazole and real antibiotic wastewater: Different role of anode and cathode.

Although has high oxidation capacity and low toxic by-product formation potential, the feasibility, mechanism, and antibiotic treatment performance of peracetic acid (PAA)-based electrochemical system remains unknown. This work systematically studied the electro-activation process of PAA, and distinguished the different mechanisms of anode and cathode. In the PAA-based electrochemical system, the anode mainly produces BDD(•OH), and the cathode is mainly the R-O• (especially CHCO•).