Reports that promote persulfate-based advanced oxidation process (AOP) as a viable alternative to hydrogen peroxide-based processes have been rapidly accumulating in recent water treatment literature. Various strategies activate peroxide bonds persulfate precursors proposed and the capacity degrade wide range of organic pollutants has demonstrated. Compared traditional AOPs which hydroxyl radical serves main oxidant, claimed involve different situ generated oxidants such sulfate singlet...

Water quality issues are a major challenge that humanity is facing in the twenty-first century. Here, we review main groups of aquatic contaminants, their effects on human health, and approaches to mitigate pollution freshwater resources. Emphasis placed chemical pollution, particularly inorganic organic micropollutants including toxic metals metalloids as well large variety synthetic chemicals. Some aspects waterborne diseases urgent need for improved sanitation developing countries also...

This study investigates the oxidation of pharmaceuticals during conventional ozonation and advanced processes (AOPs) applied in drinking water treatment. In a first step, second-order rate constants for reactions selected with ozone (kO3) OH radicals (kOH) were determined bench-scale experiments (in brackets apparent kO3 at pH 7 T = 20 °C): bezafibrate (590 ± 50 M-1 s-1), carbamazepine (∼3 × 105 diazepam (0.75 0.15 diclofenac (∼1 106 17α-ethinylestradiol ibuprofen (9.6 1.0 iopromide (<0.8...

The removal efficiency for 220 micropollutants was studied at the scale of a municipal wastewater treatment plant (WWTP) upgraded with post-ozonation followed by sand filtration. During post-ozonation, compounds activated aromatic moieties, amine functions, or double bonds such as sulfamethoxazole, diclofenac, carbamazepine second-order rate constants reaction ozone >104 M−1 s−1 pH 7 (fast-reacting) were eliminated to concentrations below detection limit an dose 0.47 g O3 g−1 dissolved...

To reduce the release of pharmaceuticals and endocrine disruptors into aquatic environment or to remove them from wastewater intended for direct indirect reuse, application advanced treatment may be required. In present study, municipal effluents were treated with ozone (O3) in a pilot-scale plant consisting two bubble columns. The investigated effluents, which varied suspended solids concentrations, comprised an effluent conventional activated sludge (CAS), same dosed 15 mg TSS L-1 (CAS +...

Abstract The ozonation of model systems and several natural waters was examined in bench-scale batch experiments. In addition to measuring the concentration ozone (O3), rate depletion an situ hydroxyl radical probe compound monitored, thus providing information on transient steady-state radicals (√OH). A new parameter, Rct , representing ratio √OH-exposure O3-exposure calculated as a function reaction time. For most tested, including pH-buffered waters, constant value for majority reaction....

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBromate Formation during Ozonization of Bromide-Containing Waters: Interaction Ozone and Hydroxyl Radical ReactionsUrs. von Gunten Juerg. HoigneCite this: Environ. Sci. Technol. 1994, 28, 7, 1234–1242Publication Date (Print):July 1, 1994Publication History Published online1 May 2002Published inissue 1 July 1994https://pubs.acs.org/doi/10.1021/es00056a009https://doi.org/10.1021/es00056a009research-articleACS PublicationsRequest reuse...

Chemical oxidants have been applied in water treatment for more than a century, first as disinfectants and later to abate inorganic organic contaminants. The challenge of oxidative abatement micropollutants is the formation transformation products with unknown (eco)toxicological consequences. Four aspects need be considered micropollutant abatement: (i) Reaction kinetics, controlling efficiency process, (ii) mechanisms product formation, (iii) extent disinfection byproducts from matrix, (iv)...

Dissolved organic matter (DOM) has recently been shown to reduce the transformation rate of various aqueous contaminants submitted oxidation by excited triplet states, apparently inhibiting intermediates. The main goals present study were evaluate in more detail effect concentration and type DOM on triplet-induced four selected compounds check for an analogous inhibition case induced hydroxyl radical. A marked was observed N,N-dimethylaniline (DMA) two antibiotics sulfamethoxazole (SMX)...

Carbonate radical (CO3•-) is a powerful oxidant that present in sunlit surface waters and treated by advanced oxidation processes. The production of CO3•- aqueous solution through carbonate anion excited triplet states aromatic ketones was investigated this study to provide new methods for the determination rate constants explore possible photoinduced pathway formation aquatic environment. Rate quenching up 3.0 × 107 M-1 s-1 yields approaching unity, determined using laser flash photolysis,...

Ozone and hydroxyl radical (•OH) reaction kinetics were measured for 14 antibacterial compounds from nine structural families, to determine whether municipal wastewater ozonation is likely result in selective oxidation of these compounds' biochemically essential moieties. Each substrate oxidized by ozone with an apparent second-order rate constant, > 1 × 103 M-1 s-1, at pH 7, the exception N(4)-acetylsulfamethoxazole ( 2.5 102 s-1). values (pH 7) macrolides, sulfamethoxazole, trimethoprim,...

The present study investigates the degradation of atrazine (2-chloro-4-(ethylamino)-6-isopropylamino-s-triazine) by ozone and OH radicals during ozonation advanced oxidation processes, with identification main products. Besides dealkylated amide products (6-amino-2-chloro-4-isopropylamino-s-triazine, 6-amino-2-chloro-4-(ethylamino)-s-triazine, 4-acetamido-2-chloro-6-isopropylamino-s-triazine, 4-acetamido-6-amino-2-chloro-s-triazine, chlorodiamino-s-triazine), two new an imine group were...

Chlorination of drinking water and municipal wastewater can create toxic chemical by-products, but alternatives pose their own set hazards.