The use of a benign fast-growing cyanobacterial species to control microcystin synthesis from .

Introduction: (), one of the most prevalent blue-green algae in aquatic environments, produces microcystin by causing harmful algal blooms (HAB). This study investigated the combined effects of nutrients and cyanobacterial subpopulation competition on synthesizing microcystin-LR.

Method: In varied nitrogen and phosphorus concentrations, cyanobacterial coculture, and algicidal DCMU presence, the growth was monitored by optical density analysis or microscopic counting, and the microcystin production was analyzed using high-performance liquid chromatography-UV.

Effects of Halides on Organic Compound Degradation during Plasma Treatment of Brines.

Plasma has been proposed as an alternative strategy to treat organic contaminants in brines. Chemical degradation in these systems is expected to be partially driven by halogen oxidants, which have been detected in halide-containing solutions exposed to plasma. In this study, we characterized specific mechanisms involving the formation and reactions of halogen oxidants during plasma treatment.

Permanganate preoxidation affects the formation of disinfection byproducts from algal organic matter.

During harmful algal blooms (HABs), permanganate may be used as a preoxidant to improve drinking water quality by removing algal cells and degrading algal toxins. However, permanganate also lyses algal cells, releasing intracellular algal organic matter (AOM). AOM further reacts with permanganate to alter the abundance of disinfection byproduct (DBP) precursors, which in turn affects DBP formation during disinfection.

Production of Dichloroacetonitrile from Derivatives of Isoxaflutole Herbicide during Water Treatment.

The herbicide isoxaflutole has the potential to contaminate drinking water directly, as well as upon hydrolyzing to its active form diketonitrile. Diketonitrile also may impact water quality by acting as a precursor for dichloroacetonitrile (DCAN), which is an unregulated but highly toxic disinfection byproduct (DBP). In this study, we investigated the reaction of diketonitrile with free chlorine and chloramine to form DCAN.

The Overlooked Photochemistry of Iodine in Aqueous Suspensions of Fullerene Derivatives.

Fullerene's low water solubility was a serious challenge to researchers aiming to harness their excellent photochemical properties for aqueous applications. Cationic functionalization of the fullerene cage provided the most effective approach to increase water solubility, but common synthesis practices inadvertently complicated the photochemistry of these systems by introducing iodide as a counterion. This problem was overlooked until recent work noted a potentiation effect which occurred when photosensitizers were used to inactivate microorganisms with added potassium iodide.

Hematite/selenium disulfide hybrid catalyst for enhanced Fe(III)/Fe(II) redox cycling in advanced oxidation processes.

Regeneration of Fe(II) is a key issue for heterogeneous advanced oxidation processes (AOPs) using iron-based catalysts. Herein, a hybrid catalyst was developed from α-FeO and SeS to enhance the Fe(III)/Fe(II) redox cycling in both hydrogen peroxide (HO) system and persulfate (PS) system. The regeneration of Fe(II) was evidenced by the increased Fe(II)/Fe(III) ratio in the used catalyst (205.

Halogen Radicals Contribute to the Halogenation and Degradation of Chemical Additives Used in Hydraulic Fracturing.

In hydraulic fracturing fluids, the oxidant persulfate is used to generate sulfate radical to break down polymer-based gels. However, sulfate radical may be scavenged by high concentrations of halides in hydraulic fracturing fluids, producing halogen radicals (e.g.