Papers by Keyword: Bromide

Abstract: An ion chromatographic method for determination of bromide and bromate in the presence of standard anions in drinking water was described. The method was based on separation on Metrosep A Supp 7-250 (250 x 4 mm) column with 3.6 mmol/L Na₂CO₃ as eluent and conductivity detection after sequential chemical and carbon dioxide suppression. The influence of flow rate and column temperature was studied and optimal experimental conditions for simultaneous determination of eight anions were chosen. Analytical characteristics of the ion chromatographic method were assessed for simultaneous determination of bromide, bromate, fluoride, chloride, nitrate, nitrite, phosphate and sulfate. The calibration curves were linear (r²=1, N=7) in the concentration ranges: 0.4-12 mg/L BrO₃^- and 0.3-11 mg/L Br^-. Recovery test was performed on a spiked certified reference material for soft drinking water. The obtained recoveries for bromate and bromide were 96.0 and 101.0 %, respectively. The repeatability and intermediate precision were between 5.1 and 0.14 % (RSD) depending on the analytes concentration. The limits of detection were 20 μg/L BrO₃^- and 10 μg/L Br^-

Abstract: The genotoxicity of drinking water have received increased attention in recent years to assess aquatic ecosystem safety. The factors affecting the genotoxicity of drinking water, including sample preparation, the concentration of bromide and ammonia nitrogen (NH₃-N), were investigated using umu test. The result showed that sample preparation and bromide could significantly influence the genotoxicity of drinking water. During sample preparation, 1 and 2 L waters concentrated were suitable for umu test and the highest yield for genotoxic compounds was obtained from acid solution (pH 2) when ethyl acetate served as the eluant. Bromide could substantially increase the genotoxicity of drinking water after chlorine disinfection. The genotoxicity of drinking water could not be increased with increasing NH₃-N concentration.

Abstract: The model of second-order reaction kinetics has been used to stimulate the monochloramine decay in model and distribution system waters by nonlinear fit. Several factors were investigated, including pH, bromide, nitrite concentrations in this system. The results showed that pH value was an important factor on the monochloramine decay rate, especially when pH was below 7.0. Presence of bromide ions had different impact under experimental conditions However, when pH was above 7.60, 0.1 mg/L concentration of bromide affect hardly the decay rate of mononchloramine. The results demonstrated that the second-order kinetic model could fit well the experimental results of monochloramine decay reaction under the conditions of bromide, and nitrite ion. Finally, the work presented here validates and extends this model for use in distribution systems under realistic chloramination conditions.