Reactivity of Cyanobacteria Metabolites with Ozone: Multicompound Competition Kinetics.

Cyanobacterial blooms occur at increasing frequency and intensity, notably in freshwater. This leads to the introduction of complex mixtures of their products, i.e.

Reaction of Amino Acids with Ferrate(VI): Impact of the Carboxylic Group on the Primary Amine Oxidation Kinetics and Mechanism.

Ferrate (Fe(VI)) is a novel oxidant that can be used to mitigate disinfection byproduct (DBP) precursors. However, the reaction of Fe(VI) with organic nitrogen, which is a potential precursor of potent nitrogenous DBPs, remains largely unexplored. The present work aimed to identify the kinetics and products for the reaction of Fe(VI) with primary amines, notably amino acids.

Kinetic and mechanistic understanding of chlorite oxidation during chlorination: Optimization of ClO pre-oxidation for disinfection byproduct control.

Chlorine dioxide (ClO) applications to drinking water are limited by the formation of chlorite (ClO) which is regulated in many countries. However, when ClO is used as a pre-oxidant, ClO can be oxidized by chlorine during subsequent disinfection. In this study, a kinetic model for the reaction of chlorine with ClO was developed to predict the fate of ClO during chlorine disinfection.

Nitriles as main products from the oxidation of primary amines by ferrate(VI): Kinetics, mechanisms and toxicological implications for nitrogenous disinfection byproduct control.

Ferrate (Fe(VI)), a promising water treatment oxidant, can be used for micropollutant abatement or disinfection byproduct mitigation. However, knowledge gaps remain concerning the interaction between Fe(VI) and dissolved organic matter structures, notably primary amines. This study investigated degradation kinetics and products of several aliphatic primary amines by Fe(VI).

Efficiency of pre-oxidation of natural organic matter for the mitigation of disinfection byproducts: Electron donating capacity and UV absorbance as surrogate parameters.

Pre-oxidation is often used before disinfection with chlorine to decrease the reactivity of the water matrix and mitigate the formation of regulated disinfection byproducts (DBPs). This study provides insights on the impact of oxidative pre-treatment with chlorine dioxide (ClO), ozone (O), ferrate (Fe(VI)) and permanganate (Mn(VII)) on Suwannee River Natural Organic Matter (SRNOM) properties characterized by the UV absorbance at 254 nm (UV) and the electron donating capacity (EDC). Changes in NOM reactivity and abatement of DBP precursors are also assessed.

Reactivity of chromophoric dissolved organic matter (CDOM) to sulfate radicals: Reaction kinetics and structural transformation.

Sulfate radical (SO) has been extensively studied as a promising alternative in advanced oxidation processes (AOPs) for water treatment. However, little is known about its reactivity to the ubiquitous dissolved organic matter (DOM) in water bodies. SO would selectively react with electron rich moieties in DOM, known as chromophoric DOM (CDOM), due to its light absorbing property.

In Situ Formation of Free Chlorine During ClO Treatment: Implications on the Formation of Disinfection Byproducts.

Chlorine dioxide (ClO) is commonly used as an alternative disinfectant to chlorine in drinking water treatment because it produces limited concentrations of halogenated organic disinfection byproducts. During drinking water treatment, the primary ClO byproducts are the chlorite (50-70%) and the chlorate ions (0-30%). However, a significant portion of the ClO remains unaccounted for.

Influence of Temperature, Relative Humidity, and Soil Properties on the Soil-Air Partitioning of Semivolatile Pesticides: Laboratory Measurements and Predictive Models.

Soil-air partition coefficient (Ksoil-air) values are often employed to investigate the fate of organic contaminants in soils; however, these values have not been measured for many compounds of interest, including semivolatile current-use pesticides. Moreover, predictive equations for estimating Ksoil-air values for pesticides (other than the organochlorine pesticides) have not been robustly developed, due to a lack of measured data. In this work, a solid-phase fugacity meter was used to measure the Ksoil-air values of 22 semivolatile current- and historic-use pesticides and their degradation products.