期刊文献+

氯离子对过硫酸盐氧化苯胺的影响 被引量:3

Effect of chloride ions on the oxidation of aniline using persulfate
原文传递
导出
摘要 在高级氧化工艺(AOPs)降解有机污染物过程中,卤代消毒副产物(DBPs)的形成已引起了广泛的关注。然而,氯离子(Cl^(-))在过硫酸盐(PS)降解污染物的过程中的作用机制仍存在争议。基于此,探究了在不同pH下Cl^(-)对PS的作用机理,并对可能的反应途径进行了推断。结果表明:在酸性条件(pH=2.5)下,Cl^(-)可以与PS反应生成HClO,从而可促进对苯胺(AN)的去除,但并不能对AN进行有效矿化,在PS溶液中加入10 mmol·L^(-1)的Cl^(-)后,AN的去除率升高了47.82%,但TOC去除率仅提高了9.78%,且会生成2,4,6-三氯苯胺等有害的氯代副产物;相反,在中性(pH=7.5)或碱性条件(pH=11.5)下PS自身能够有效矿化AN,AN的去除率分别提高了57.90%和74.96%,此时TOC去除率分别升高了44.98%和67.15%,而Cl^(-)的作用并不显著。通过加入不同淬灭剂对反应过程中的氧化物质进行了识别,发现PS在碱性条件下会生成羟基自由基(HO·)、硫酸根自由基(SO_(4)^(-·))和超氧自由基(O_(2)^(-·)),且在反应过程中起主要作用的为HO·。在碱性条件下,当苯胺的去除率为74.96%时,HO·、SO_(4)^(-·)和O_(2)^(-·)对苯胺去除的贡献率分别为51.36%、11.25%和9.79%。对NaCl/PS体系中的产物进行鉴定,检测到7种中间产物,并在此基础上探讨了PS氧化降解AN的可能途径。以上研究结果有助于更好地理解和优化与PS相关的高级氧化技术在实际应用中的污染控制。 The formation of halogenated disinfection by-products(DBPs) during organic pollutants degradation in advanced oxidation process(AOPs) has raised growing concerns. However, the detailed roles of chlorine ions(Cl^(-)) in pollutant degradation by persulfate(PS) remain controversial so far. Herein, the degradation mechanisms of Cl^(-) on PS at different pH were investigated, and the pathway of reaction process was proposed in the presence/absence of Cl^(-). The results showed that at acidic condition(pH=2.5), PS could not directly react with AN but could active Cl^(-) to generate HClO. The removal rate of AN increased from 2.95% to 47.82% when10 mmol·L^(-1) Cl^(-) was added in PS solution. This process would be helpful to degrade AN, but it cannot completely mineralize AN, and will produce 2, 4, 6-Trichlorobenzenamine and other chlorinated by-products. At neutral(pH=7.5) or alkaline condition(pH=11.5), PS alone can effectively mineralize AN and the impact of Clbecame negligible, the corresponding removal rates of AN increased by 57.90% and 74.96%, of TOC increased by 44.98% and 67.15%, respectively. By adding radical scavengers, we proved that the degradation of AN occurred as a result of reactions initiated by SO_(4)^(-), HO·, and O_(2)^(-) at alkaline condition, and HO· played the dominant role in the degradation process. When the removal rate of AN was 74.96%, the respective contributions of HO·,SO_(4)^(-) and O_(2)^(-) to AN removal were 51.36%, 11.25% and 9.79%, respectively. Based on the analysis of GC-MS, 7 major intermediate products were identified in Na Cl/PS systems. Tentative pathways for the degradation of AN were proposed. Our findings may benefit an improved understanding and optimization of PS-associated AOPs for pollution control in real environmental towards high sustainability and ecological security.
作者 谷永 闫志明 王兴 胡悦立 李霞 孙贻超 GU Yong;YAN Zhiming;WANG Xing;HU Yueli;LI Xia;SUN Yichao(Tianjin Academy of Eco-Environmental Sciences,Tianjin 300191,China)
出处 《环境工程学报》 CAS CSCD 北大核心 2021年第8期2627-2638,共12页 Chinese Journal of Environmental Engineering
基金 国家水体污染控制与治理科技重大专项(2017ZX07107-005)。
关键词 过硫酸钠 氯离子 苯胺 活性氯 反应机理 persulfate chloride ions aniline reactive chlorine species reaction mechanism
  • 相关文献

参考文献4

二级参考文献17

共引文献107

同被引文献13

引证文献3

二级引证文献2

相关作者

内容加载中请稍等...

相关机构

内容加载中请稍等...

相关主题

内容加载中请稍等...

浏览历史

内容加载中请稍等...
;
使用帮助 返回顶部