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臭氧(O3)能有效氧化去除废水中的微量有机污染物,但其较高的成本限制了在我国废水处理中的应用.因此,开发新型的O3高级氧化技术以提高O3的利用率,已成为亟待解决的问题.本研究发现,羟胺(NH2OH)可大幅提高连续流O3氧化去除农药阿特拉津(ATZ)的效率.与单独臭氧氧化体系相比,当[NH2OH]0∶[O3]s(摩尔浓度比)=0.25时,反应3 min时的ATZ去除率([O3]s∶[ATZ]0=10,pH 7.0)由37.9％提高至83.8％.当[NH2OH]0∶[O3]s=0.25-0.75时,反应前3 min内的加速程度随NH2OH初始浓度的升高而降低,随后在0.75比例下的加速程度升高,这与[NH2OH]∶[O3]s在反应过程中的持续降低及二级氧化剂生成的变化有关.二级氧化剂的生成种类和浓度主要受[NH2OH]0∶[O3]s影响,有羟基自由基生成.反应3 min后,在0.25比例下二级氧化剂主要通过攻击ATZ的烷基等含碳基团加速其降解,0.75比例下二级氧化剂对含氯基团的攻击加剧.本研究将为利用NH2OH开发新型的O3高级氧化技术提供依据.

Ozone (O3) is effective for the removal of micropollutants in wastewater,while its relatively high cost limited the application for wastewater treatment in China.Therefore,there is an urgent need to develop new O3-based advanced oxidation processes (AOPs) to improve its utilization efficiency.This study found that hydroxylamine (NH2OH) could significantly enhance the degradation of atrazine (ATZ) by continuous ozonation treatment.Compared to ozonation alone,at a molar ratio of [NH2OH]0∶[O3]s=0.25,the removal efficacy of ATZ at a reaction time of 3 min increased from 37.9％ to 83.8％ ([O3]s∶[ATZ]0 =10,pH 7.0).At [NH2OH]0∶[O3]s=0.25-0.75,the degree of acceleration decreased with an increase in the initial NH2 OH concentration within the first 3 min,and then the acceleration became stronger at [NH2OH] 0 ∶ [O3]s =0.75,which arose from the continuous decrease in the [NH2OH]∶[O3]s ratio during the reaction and the varied formation of secondary oxidants.The formed species and concentration of secondary oxidants were mainly affected by the [NH2 OH] 0 ∶ [O3]s ratio,and hydroxyl radicals were formed.After a reaction time of 3 min,the secondary oxidants mainly enhanced the degradation of ATZ through attacking its carbon-based groups (e.g.,alkyl) at [NH2OH] 0∶ [O3]s =0.25,whereas the attack of the secondary oxidants on chlorine-beating groups of ATZ became stronger at [NH2OH] 0∶[O3]s=0.75.This study will provide a basis for developing new O3-based AOPs by using NH2OH.