摘要
采用氨三乙酸(NTA)强化和改善零价铁/过一硫酸盐(Fe0/PMS)体系降解水中偶氮染料的氧化效能,以橙黄G(OG)为目标污染物,研究了NTA强化Fe0/PMS(NTA/Fe0/PMS)体系中OG的降解效果和NTA的强化作用机制,并考察了NTA、Fe0、PMS等主要反应物浓度和水中常见的共存物质对OG降解效能的影响.结果表明,NTA能够强化Fe0/PMS体系降解OG的氧化效能,且初始pH值对其强化作用有显著影响.中性(pH=7)和酸性(pH=3)条件下,NTA/Fe0/PMS体系去除OG的表观速率常数分别较Fe0/PMS体系提高了31.3倍和5.5倍;增加NTA、Fe0和PMS浓度有助于OG的降解,但NTA超过8mmol/L或PMS超过1.0mmol/L时出现抑制现象;水质背景中,Cl-的存在促进了OG的降解,HCO3-、H2PO4-和腐殖酸则表现为不同程度的抑制作用;NTA/Fe0/PMS体系中,主导的活性物种为Fe0界面产生的SO4•-和•OH,界面作用和均相作用对OG的降解分别贡献了约83.2%和16.8%;加入NTA后,体系中生成的Fe3+/Fe2+能与其迅速形成络合物,既缓解了Fe0表面钝化层的形成,促进Fe0界面对PMS的直接活化,又提高了溶液中溶解性铁的浓度,促进均相作用对PMS的活化分解,使NTA/Fe0/PMS体系降解OG的氧化效能得到强化和改善.
Nitrilotriacetic acid(NTA)was applied to enhance and improve the oxidation efficiency of azo dyes in Fe^(0)/PMS system.Taking Orange G(OG)as the target pollutant,the degradation efficiency of OG,the strengthening role of NTA,the effects of NTA,Fe^(0),PMS and general coexistence substances in water on the degradation of OG were studied in Fe0/PMS system enhanced with NTA(NTA/Fe0/PMS).The results demonstrated that the introduction of NTA could enhance the degradation of OG by Fe0/PMS system,and the initial pH had a significant effect on the enhancement.Under neutral(pH=7)and acidic(pH=3)conditions,the apparent rate constants of OG removal by NTA/Fe^(0)/PMS system were 31.3 times and 5.5 times higher than those of Fe^(0)/PMS system,respectively.Increasing the concentration of NTA,Fe^(0) and PMS facilitated the degradation of OG,but negative effects were observed when NTA or PMS concentration were over 8mmol/L and 1.0mmol/L,respectively.In the context of water quality,the presence of Cl-promoted the degradation of OG,while HCO_(3),H_(2)PO_(4)-and Humic Acid showed different degrees of inhibition.In NTA/Fe^(0)/PMS system,SO_(4)•-and•OH produced at Fe^(0) interface was confirmed to be the dominant active species responsible for OG degradation,and heterogeneous and homogeneous activation of PMS contributed about 83.2%and 16.8%to the degradation of OG,respectively.When adding NTA to Fe^(0)/PMS system,Fe^(3+)/Fe^(2+)generated could be complexed rapidly with NTA,which not only alleviated the formation of passive layer and promoting the direct activation of PMS on Fe^(0) interface,but also increased the concentration of soluble iron in system,promoting the activation of PMS by homogeneous interaction.Thus,the degradation effect of OG in Fe^(0)/PMS system was enhanced by NTA.
作者
马红芳
杨浩宇
田委民
伍凌斌
陈秀峰
邹景
MA Hong-fang;YANG Hao-yu;TIAN Wei-min;WU Ling-bin;CHEN Xiu-feng;ZOU Jing(Department of Municipal Engineering,College of Civil Engineering,Huaqiao University,Xiamen 361021,China;College of Chemical Engineering,Huaqiao University,Xiamen 361021,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2021年第4期1597-1607,共11页
China Environmental Science
基金
国家自然科学基金资助项目(51708231)
福建省自然科学基金资助项目(2018J05084)。
关键词
氨三乙酸
零价铁
过一硫酸盐
活性物种
偶氮染料
nitrilotriacetic acid
zero valent iron
peroxymonosulfate
active species
azo dyes
