The occurrence of alachlor in natural drinking water sources raises concerns due to adverse health effects. Advanced oxidation with zero valent iron activating persulfate (ZVI/PS) can degrade alachlor with great potential. But no information was reported about effect of ZVI/PS preoxidation on the generation of disinfection byproducts (DBPs) during the downstream chlorination of alachlor. The objective was to investigate DBP formation through chlorination of alachlor preoxidized by ZVI/PS. The results found that ZVI/PS preoxidation enhanced the DBP formation, compared with original system without any treatment. The longer the preoxidation time of ZVI/PS during the experiment, the more DBPs that were generated. During 48.0 h chlorination time, the produced DBPs increased to a stable value. Nitrate posed almost no impact on the DBP formation in the ZVI/PS system, while chloride significantly decreased DBP formation, which was attributed to the reduction of trichloromethane. During the chlorination process, alachlor could be further oxidized by remaining PS and free chlorine collectively. ZVI/PS had little effect on the DBP formation in the real water matrix. However, it could reduce carbonaceous DBP formation and increase nitrogenous DBP formation when the real water matrix contained 100 μg/L alachlor. The acute toxicity of alachlor solution could be reduced by the ZVI/PS system, while after chlorination the acute toxicity was largely increased due to the formation of DBPs. With increase of PS concentration, the DBP formation decreased in the ZVI/PS preoxidation system and increased in the system with PS alone. In conclusion, application of ZVI/PS in actual water containing alachlor declined DBP generation by augmenting PS concentration which should consider standard limited value of sulfate. Further investigation is needed for high bromide water.

由于不良的健康影响，天然饮用水中甲草胺的存在引起了人们的关注。零价铁活化过硫酸盐（ZVI / PS）进行的高级氧化可降解甲草胺，具有很大的潜力。但尚无关于ZVI / PS预氧化对甲草胺下游氯化过程中消毒副产物（DBPs）产生的影响的报道。目的是研究通过ZVI / PS预氧化的甲草胺氯化生成DBP的方法。结果发现，与未经任何处理的原始系统相比，ZVI / PS预氧化增强了DBP的形成。在实验过程中ZVI / PS的预氧化时间越长，生成的DBP越多。在48.0小时的氯化时间内，生成的DBP增加到稳定值。硝酸盐对ZVI / PS系统中DBP的形成几乎没有影响，而氯化物显着降低了DBP的形成，这归因于三氯甲烷的减少。在氯化过程中，甲草胺可被残留的PS和游离氯共同氧化。ZVI / PS对实际水基质中DBP的形成影响很小。但是，当实际水基质中含有100μg/ L甲草胺时，它可以减少碳质DBP的形成并增加含氮DBP的形成。ZVI / PS系统可以降低甲草胺溶液的急性毒性，而氯化后，由于DBP的形成，急性毒性大大增加。随着PS浓度的增加，ZVI / PS预氧化系统中DBP的形成减少，而单独使用PS的系统中DBP的形成增加。综上所述，在含有甲草胺的实际水中使用ZVI / PS可以通过增加PS的浓度来降低DBP的生成，应考虑硫酸盐的标准限量值。高溴化物水需要进一步研究。