Chokka squid (Loligo reynaudii) from three sites along the South African coast were analyzed for halogenated natural products (HNPs) and anthropogenic persistent organic pollutants (POPs). HNPs were generally more than one order of magnitude more abundant than POPs. The most prevalent pollutant, i.e. the HNP 2,3,3′,4,4′,5,5′-heptachloro-1′-methyl-1,2′-bipyrrole (Q1), was detected in all chokka squid samples with mean concentrations of 105, 98 and 45 ng/g lipid mass, respectively, at the Indian Ocean (site A), between both oceans (site B) and the South Atlantic Ocean (site C). In addition, bromine containing polyhalogenated 1′-methyl-1,2′-bipyrroles (PMBPs), 2,4,6-tribromophenol (2,4,6-TBP, up to 28 ng/g lipid mass), polybrominated methoxy diphenyl ethers, MHC-1, TBMP and other HNPs were also detected. Polychlorinated biphenyls (PCBs) were the predominant class of anthropogenic POPs. PCB 153 was the most abundant PCB congener in chokka squid from the Indian Ocean, and PCB 138 in samples from the South Atlantic Ocean and between both oceans.

Ionic liquids (ILs) are extensively used in several chemistry fields. And research about the effects of ILs on soil microbes is needed. In this study, brown soil was exposed to 1-butyl-3-methylimidazolium bromide ([C₄mim]Br), 1-hexyl-3-methylimidazolium bromide ([C₆mim]Br) and 1-decyl-3-methylimidazolium bromide ([C₁₀mim]Br). The toxicities of the three ILs are evaluated by measuring the soil culturable microbial number, enzyme activity, microbial diversity and, abundance of the ammonia monooxygenase (amoA) genes of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA). Results showed that all tested ILs caused a decrease in culturable microbial abundance. Tested ILs exposure inhibit urease activity and promote acid phosphatase and β-glucosidase activities. Tested ILs reduced soil microbial diversity and the abundances of AOB-amoA and AOA-amoA genes significantly. After a comparison of the integrated biomarker response (IBR) index, the toxicities of tested ILs to soil microorganisms were as follows: [C₁₀mim]Br > [C₆mim]Br > [C₄mim]Br. Among all collected biomarkers, the abundance of the AOA-amoA gene was the most sensitive one and was easily affected after ILs exposure.

Concerns regarding disinfection by-product (DBP) formation during drinking water treatment have led water utilities to apply treatment processes to reduce the concentration of DBP precursor natural organic matter (NOM). However, these processes often do not remove bromide, leading to high bromide to dissolved organic carbon (DOC) ratios after treatment, which can increase the formation of more toxic brominated DBPs. In the current study, we investigated the formation and effect of DBPs in a matrix of synthetic water samples containing different concentrations of bromide and DOC after disinfection with chlorine. Trihalomethanes and haloacetic acids were analysed by chemical analysis, while effect was evaluated using in vitro bioassays indicative of the oxidative stress response and bacterial toxicity. While the addition of increasing bromide concentrations did not alter the sum molar concentration of DBPs formed, the speciation changed, with greater bromine incorporation with an increasing Br:DOC ratio. However, the observed effect did not correlate with the Br:DOC ratio, but instead, effect increased with increasing DOC concentration. Water samples with low DOC and high bromide did not exceed the available oxidative stress response effect-based trigger value (EBT), while all samples with high DOC, irrespective of the bromide concentration, exceeded the EBT. This suggests that treatment processes that remove NOM can improve drinking water quality, even if they are unable to remove bromide. Further, iceberg modelling showed that detected DBPs only explained a small fraction of the oxidative stress response, supporting the application of both chemical analysis and bioanalysis for monitoring DBP formation.

Using quantum chemistry methods, mechanisms and products of the CHBr₂O₂ + HO₂ reaction in the atmosphere were investigated theoretically. Computational result indicates that the dominant product is CHBr₂OOH + O₂ formed on the triplet potential energy surface (PES). While CBr₂O + OH + HO₂ produced on the singlet PES is subdominant to the overall reaction under the typical atmospheric condition below 300 K. Due to higher energy barriers surmounted, other products including CBr₂O₂ + H₂O₂, CBr₂O + HO₃H, CH₂O + HO₃Br, CHBrO + HO₃ + Br, and CHBr₂OH + O₃ make minor contributions to the overall reaction. In the presence of OH radical, CHBr₂OOH generates CHBr₂O₂ and CBr₂O₂ + H₂O subsequently, which enters into new Br-cycle in the atmosphere. The substitution effect of alkyl group and halogens plays negligible roles to the dominant products in the RO₂ + HO₂ (X = H, CH₃, CH₂OH, CH₂F, CH₂Cl, CH₂Br, CH₂Cl, and CH₂Br) reactions in the atmosphere.

Trihalomethanes (THMs) and adsorbable organic halides (AOX) were generated in chlorinated water. The purpose of the study was to provide a comprehensive picture of concentration distribution, the seasonal and different water source variability of THMs and AOX. Data for THMs, AOX, and other physico-chemical parameters were from 538 samples of 16 drinking water work through a 3-year sampling program which was conducted in Shandong province with typical temperate and monsoonal climate. Selected samples were considered with the influence of factors such as season, water source, and disinfectant. The THMs and AOX concentration of the samples disinfected with chlorine ranged from 2.1–105 μg/L and 11–238 μg/L, respectively. The THMs and AOX concentration of the samples disinfected chlorine dioxide ranged from N.D.–47.6 μg/L and N.D.–102 μg/L, respectively. The median concentration of THMs and AOX of samples disinfected with chlorine were 35 μg/L and 61 μg/L, much higher than chlorine dioxide, respectively. Ninety-two percent of the samples disinfected with chlorine and all samples disinfected with chlorine dioxide met Chinese drinking water standard for THMs. The ratio of tribromethane (TBM) to THMs of samples disinfected with chlorine was 19%, lower than chlorine dioxide 42%. Bromine substitution factor (BSF) of THMs and initial concentration of bromide showed weak correlation, and the Spearman correlation coefficient was 0.38. THMs and AOX concentrations showed noticeable seasonal variations with the highest median concentrations in spring. The levels of THMs and AOX in drinking water varied with different water sources and followed the order local reservoir > Yellow River reservoir > ground water. The survey results complement the database of THMs and AOX occurrence in drinking water in China, and offer a significant reference data for setting disinfections by-products occurrence in countries or regions with similar climate around the world.

Pollution from bromine and some of its related compounds is currently unregulated in soil from Russia and other countries, and tools for sound assessment of environmental impacts of bromine contamination are largely missing. Hence, assessing potential implications for humans and ecosystems of bromine soil contamination is urgently needed, which requires the combination of measured soil concentrations from environmental studies and quantified potential toxicity impacts. To address this need, we used data from an experimental study assessing bromine in soils (384 samples) of Tomsk oblast, Russia, starting from measured concentrations obtained by Instrumental Neutron Activation Analysis in an earlier study. From these data, we calculated the bromine mass in soils and used these as starting point to characterize related cumulative impacts on human health and ecosystems in the Tomsk region, using a global scientific consensus model for screening-level comparative toxicity characterization of chemical emissions. Results show that the combination of sampling methodology with toxicity characterization techniques presents a new approach to be used in environmental studies aimed at environmental assessment and analysis of a territory. Our results indicate that it is important to account for substance-specific chemical reaction pathways and transfer processes, as well as to consider region-specific environmental characteristics. Our approach will help complement environmental assessment results with environmental sustainability elements, to consider potential tradeoffs in impacts, related to soil pollution, in support of improved emission and pollution reduction strategies.

Halogenated organics are widely used in modern industry, agriculture, and medicine, and their large-scale emissions have led to soil and water pollution. Electrochemical methods are attractive and promising techniques for wastewater treatment and have been developed for degradation of halogenated organic pollutants under mild conditions. Electrochemical techniques are classified according to main reaction pathways: (i) electrochemical reduction, in which cleavage of C-X (X = F, Cl, Br, I) bonds to release halide ions and produce non-halogenated and non-toxic organics and (ii) electrochemical oxidation, in which halogenated organics are degraded by electrogenerated oxidants. The electrode material is crucial to the degradation efficiency of an electrochemical process. Much research has therefore been devoted to developing appropriate electrode materials for practical applications. This paper reviews recent developments in electrode materials for electrochemical degradation of halogenated organics. And at the end of this paper, the characteristics of new combination methods, such as photocatalysis, nanofiltration, and the use of biochemical method, are discussed.