摘要
垃圾渗滤液中普遍存在的氯离子(Cl-)会与高级氧化体系产生的HO^(·)和SO_(4)^(·-)发生反应,生成活性氯物种(RCS),进而影响有机物的降解效率并改变氧化副产物的生成路径.本研究采用静电场轨道阱质谱(Orbitrap MS),系统探究了Cl^(-)对芬顿(Fenton)和热活化过硫酸盐(Heat/PDS)体系处理垃圾渗滤液生物处理出水(BTLE)时氧化副产物生成的影响机制.结果表明,当Cl^(-)浓度从2000 mg·L^(-1)增加至40000 mg·L^(-1)时,Fenton和Heat/PDS体系去除BTLE-DOM过程中TOC的去除率分别从36.0%和86.7%大幅降低至0和63.4%.从分子组成的角度发现,Cl^(-)的存在促进了两种体系中高氧类(O/C>0.5)副产物的生成:在Fenton和Heat/PDS体系中分别检测到1478和894种不含Cl的副产物,以及379和470种含Cl副产物,这些产物主要具有高氧高度不饱和酚类结构.进一步的反应路径解析表明,无Cl副产物主要通过加氧、去甲基、脱羧和去羟基化等反应途径形成,而含Cl副产物主要通过氯取代(Cl+H-)和次氯酸加成(HOCl+)反应途径形成.本研究从分子转化层面揭示了Cl^(-)对氧化副产物生成的影响规律,为高氯渗滤液处理工艺的优化提供了理论支撑.
Chloride ions(Cl^(-)),which are commonly present in landfill leachate,can react with radical species such as HO^(·)and SO_(4)^(·-)generated in advanced oxidation processes(AOPs)to form reactive chlorine species(RCS).These RCS can influence the degradation efficiency of organic matter and change the formation pathway of oxidation byproducts(OBPs).This study employed Orbitrap mass spectrometry(Orbitrap MS)to systematically investigate the impact mechanisms of Cl^(-)on the formation of OBPs when the biologically treated leachate effluent(BTLE)was treated by the Fenton and heat-activated peroxydisulfate(Heat/PDS)processes.The results showed that as the Cl^(-)concentration increased from 2000 mg·L^(-1)to 40000 mg·L^(-1),the total organic carbon(TOC)removal efficiency for dissolved organic matter(DOM)in BTLE decreased significantly from 36.0%to 0 for the Fenton process and from 86.7% to 63.4% for the Heat/PDS process.At the molecular level,the presence of Cl^(-)promoted the formation of high-oxygen(O/C>0.5)OBPs in both the Fenton and Heat/PDS processes.Specifically,1478 and 894 Cl^(-)free OBPs,as well as 379 and 470 Cl^(-)containing OBPs,were identified in the Fenton and Heat/PDS processes,respectively.These byproducts predominantly exhibited highly unsaturated phenolic structures with high oxygen content.Furthermore,formation pathway analysis indicated that Cl^(-)free OBPs were primarily formed through oxygen addition,demethylation,decarboxylation,and dehydroxylation reactions.In addition,Cl^(-)containing OBPs were mainly formed through chlorine substitution(Cl+H-)and addition(HOCl+)reactions.This study revealed the influence rules of Cl^(-)on the formation of OBPs at the molecular transformation level,providing theoretical support for the optimization of treatment processes for high-chloride leachate.
作者
罗杨
房飞燕
何晨
陈炜鸣
LUO Yang;FANG Feiyan;HE Chen;CHEN Weiming(School of Environmental Science and Engineering,Southwest Jiaotong University,Chengdu 611756;State Key Laboratory of Heavy Oil Processing,China University of Petroleum(Beijing),Beijing 102249)
出处
《环境科学学报》
北大核心
2025年第7期307-316,共10页
Acta Scientiae Circumstantiae
基金
四川省自然科学基金面上项目(No.2023NSFSC0350)
西南交通大学新型交叉学科培育基金(No.2682022KJ036,2682025QZ031)。
关键词
垃圾渗滤液
芬顿体系
热活化过硫酸盐体系
难降解有机物
氯离子
landfill leachate
Fenton process
heat-activated peroxydisulfate process
refractory organic matter
chloride ions
