典型卤代酚类嗅味物质在预氯化及消毒过程中的生成与转化特性研究

Formation and transformation characteristics of typical halogenated phenolic odor compounds in the process of prechlorination and disinfection

针对含酚原水,研究了预氯化及消毒过程中4种典型卤代酚类嗅味物质的生成和转化特性。结果表明,含酚原水在预氯化过程中会生成2-溴酚、2,6-二氯酚、2,4-二溴酚、2,6-二溴酚等典型卤代酚类嗅味物质,其生成量随反应时间呈现先升高后降低趋势。4种卤代酚类嗅味物质是氯化过程的中间产物,预氯化能将其进一步转化为其他副产物。模拟水厂工艺处理含酚原水过程中,4种卤代酚类嗅味物质的浓度峰值均出现在预氯化阶段,且生成量受苯酚浓度和次氯酸钠投量影响较大;采用不同的预氯化-消毒组合方式对4种卤代酚类嗅味物质的最终剩余浓度影响不大;低浓度含酚原水经处理后水中2,6-二氯苯酚和2,6-二溴苯酚存在超出嗅阈值风险,高浓度含酚原水经处理后水中2,6-二氯苯酚、2,4-二溴苯酚和2,6-二溴苯酚存在超出嗅阈值情况。对于含酚或者含卤代酚类嗅味物质的原水,不建议直接进行氯化处理。

The generation and transformation characteristics of 4 typical halogenated phenolic odor compounds in the process of prechlorination and disinfection were studied for the raw water containing phenols. The results showed that typical halogenated phenols, such as 2-bromophenol, 2,6-dichlorophenol, 2,4-dibromohenol, 2,6-dibromohenol, were generated in the pre-chlorination process of phenol-containing raw water, and the formation amount increased first and then decreased with the reaction time.The four halogenated phenols were intermediates in the chlorination process, which could be further converted into other by-products by pre-chlorination. In the process of treating phenol-containing raw water with simulated waterworks process, the concentration peaks of the four halogenated phenolic odor compounds all appeared in the pre-chlorination stage, and the amount was greatly affected by the concentration of phenol and the dosage of sodium hypochlorite. Combination mode of pre-chlorination and disinfection had little effect on the final residual concentration of the four halogenated phenols. 2,6-dichlorophenol and 2,6-dibromophenol were at risk of exceeding the smelling threshold after disinfection of raw water containing low concentration phenols, while 2,6-dichlorophenol, 2,4-dibromophenol and 2,6-dibromophenol all exceeded the smelling threshold after disinfection of raw water containing high concentration phenol. For raw water containing phenols or halogenated phenols, direct chlorination is not recommended.