主次波长—甲酚红褪色光度法测定溴化物

一般天然水溴化物含量较低,当水体受到化工、制药等废水污染时,Br~-升高。Br~-在 pH 5溶液中催化褪色,本文在此基础上依据胶体光谱性质,研究主次双波长比色法,可提高单纯催化光度法分析灵敏度,而且精密度、准确度良好,适用于≥0.02 mg/L 的清洁水分析。     

Effect of ferric and bromide ions on the formation and speciation of disinfection byproducts during chlorination

The e ects of ferric ion, pH, and bromide on the formation and distribution of disinfection byproducts (DBPs) during chlorination were studied. Two raw water samples from Huangpu River and Yangtze River, two typical drinking water sources of Shanghai, were used for the investigation. Compared with the samples from Huangpu River, the raw water samples from Yangtze River had lower content of total organic carbon (TOC) and ferric ions, but higher bromide concentrations. Under controlled chlorination conditions, four trihalomethanes (THMs), nine haloacetic acids (HAAs), total organic halogen (TOX) and its halogen species fractions, including total organic chlorine (TOCl) and total organic bromide (TOBr), were determined. The results showed that co-existent ferric and bromide ions significantly promoted the formation of total THMs and HAAs for both raw water samples. Higher concentration of bromide ions significantly changed the speciation of the formed THMs and HAAs. There was an obvious shift to brominated species, which might result in a more adverse influence on the safety of drinking water. The results also indicated that high levels of bromide ions in raw water samples produced higher percentages of unknown TOBr.