Enhanced degradation of lindane in water by sulfite-assisted ultrasonic (SF/US) process: The critical role of generated aqueous electrons.

Persistent pesticides pose significant environmental and health risks due to their strong resistance to conventional degradation methods. This study investigates the degradation of lindane (LND), a perchlorinated pesticide, using a sulfite-assisted ultrasonic (SF/US) process, focusing on the critical role of aqueous electrons (e) in reductive dechlorination. Aqueous electrons were indirectly identified as the primary reactive species in the SF/US system for pollutant degradation, providing insights into US-induced reduction mechanisms.

Removal of pesticide residues from fresh vegetables by the coupled free chlorine/ultrasound process.

Pesticide residue in vegetables has been considered as a serious food safety problem across the whole world. This study investigates a novel advanced oxidation process (AOP), namely the coupled free chlorine/ultrasound (FC/US) process for the removal of three typical pesticides from lettuce. The removal efficiencies of dimethoate (DMT), trichlorfon (TCF) and carbofuran (CBF) from lettuce reached 86.

Treatment of fluorine-containing pharmaceutical wastewater by VUV/UV process.

As an advanced oxidation process, vacuum ultraviolet/ultraviolet (VUV/UV) has been intensively studied for drinking water treatment, but assessment of its feasibility for wastewater treatment has rarely been conducted. This study investigated the treatment of fluorine-containing pharmaceutical wastewater by VUV/UV process and examined the defluorination and therefore the improvement of biodegradability of the wastewater after the process. The results indicated that the degradation of a model fluorine-containing organic compound (namely, 4-fluorophenol) was mainly achieved via the attack of the fluorine atom linking directly to the aromatic ring by the HO generated from VUV photolysis of water.

Dimethoate degradation by VUV/UV process: Kinetics, mechanism and economic feasibility.

Vacuum ultraviolet/ultraviolet (VUV/UV) process has been applied to water treatment recently, but little is known about its efficacy and mechanism for pesticide degradation. This study investigated the degradation kinetics and mechanism of a typical organophosphorus pesticide, dimethoate (DMT) by VUV/UV, and then the economic feasibility was assessed. DMT degradation followed well the pseudo-first-order reaction kinetics at an initial concentration of ≤5.

Degradation of six typical pesticides in water by VUV/UV/chlorine process: Evaluation of the synergistic effect.

Vacuum ultraviolet/ultraviolet/chlorine (VUV/UV/chlorine) is considered a novel advanced oxidation process (AOP), but little is known about its kinetics for pollutant degradation in water treatment. This study investigated the degradation of six typical pesticides, namely dimethoate (DMT), atrazine (ATZ), prometon (PMT), propoxur (PPX), bromacil (BRM) and propachlor (PPC), by VUV/UV/chlorine. The results show that all pesticides were rapidly degraded by VUV/UV/chlorine with a high removal efficiency of over 95% after 60 s.

Trace Organic Pollutant Removal by VUV/UV/chlorine Process: Feasibility Investigation for Drinking Water Treatment on a Mini-Fluidic VUV/UV Photoreaction System and a Pilot Photoreactor.

The vacuum-ultraviolet/ultraviolet/chlorine (VUV/UV/chlorine) process, with a VUV/UV mercury lamp used as the light source, was found to be a highly efficient advanced oxidation process (AOP) in a previous study. Hence, its application feasibility for trace organic pollutant removal from drinking water becomes attractive. In this work, a bench-scale mini-fluidic VUV/UV photoreaction system was used to determine the degradation kinetics of sulfamethazine (SMN), a model sulfonamide antibiotic frequently detected with trace levels in aquatic environments.

A Green Method to Determine VUV (185 nm) Fluence Rate Based on Hydrogen Peroxide Production in Aqueous Solution.

A mini-fluidic vacuum ultraviolet/ultraviolet (VUV/UV) photoreaction system (MVPS) was developed in our previous study. Based on the MVPS, a green method to determine VUV fluence rate has been developed using the production rate of H O when water is exposed to 185 nm VUV. The H O production followed pseudo-zero-order reaction kinetics well over the first 10 min of VUV/UV exposure.