溴离子对三卤甲烷生成量的影响因素研究

Factors Affecting the Formation of Trihalomethanes by Bromide Ions

溴代消毒副产物的细胞毒性要高于氯代消毒副产物,因而成为近年来消毒领域的研究热点之一。以北方某水源水为研究对象,研究溴离子浓度对三卤甲烷(THMs)和可吸附有机卤化物(AOX)的影响,并考察含溴水体中THMs总生成量及其成分分布与投氯量、pH值和温度的关系,以及该过程中溴对THMs的贡献程度。结果表明,溴离子投量由零增加至900μg/L后,THMs的优势种由CHCl3转化为氯溴混合型THMs,生成的AOBr在AOX中的占比由5.08%增加至36.35%。在溴离子投加量为900μg/L时,提高投氯量、pH值和温度均会提高THMs的总生成量;但对于Br-THMs来说,投氯量增加与温度升高均会抑制溴对THMs的贡献程度,两种因素变化下,溴取代参数(BSF)由0.64和0.62分别降至0.51和0.50;而提高pH值,溴化THMs的程度则有所增加,BSF由0.49升高至0.57。

The cytotoxicity of brominated disinfection by-products is higher than that of chlorinated disinfection by-products, and thus has become a research focus in the field of disinfection in recent years. Taking source water in the northern China as the research object, the effects of bromide ion concentration on trihalomethanes ( THMs) and adsorbable organic halide ( AOX) were studied. The effects of chlorine dosage, pH and temperature on the total amounts of THMs and the distribution of THMs components in bromine-containing water were investigated. Besides, the contribution of bromine to THMs was also discussed. The results showed that, when the dosage of bromide ion increased from zero to 900 μg/L, the dominant species of THMs were transformed from CHC13 to chlorobromide mixed THMs, and the proportion of AOBr in AOX increased from 5. 08% to 36. 35%. When the dosage of bromine ion was 900 μg/L, the total production of THMs increased with the increase of chlorine dosage, pH and temperature.However, for Br-THMs, the increase of chlorine dosage and temperature would inhibit the contribution of bromine to THMs. BSF decreased from 0. 64 and 0. 62 to 0. 51 and 0. 50, respectively. But with the increase of pH, the bromination degree of THMs increased, and BSF increased from 0. 49 to 0. 57.