零价铁活化过氧乙酸降解水中双酚A的效果与机制

Effect and mechanism on the degradation of aqueous bisphenol A by zero valent iron activated peroxyacetic acid system

双酚A(BPA)是含酚工业废水中代表性污染物,采用零价铁(ZVI)活化过氧乙酸(PAA)去除水中BPA,探究了ZVI和PAA投量、pH以及工业废水中典型共存阴离子对PAA活化和BPA降解的影响,并通过探究反应活性物种和活性位点解析了ZVI活化PAA的反应机制。在投加50 mg/L ZVI,1.00 mmol/L PAA和初始pH为3.4的最优工艺条件下,ZVI/PAA体系反应30 min可去除水中99.24%的BPA;HCO_(3)^(-)和SO_(4)^(2-)对BPA降解具有抑制作用,Cl^(-)(0~20.0 mmol/L)则加速BPA降解。反应中ZVI及其表面氧化层分别释放溶解性Fe(Ⅱ)和Fe(Ⅲ),溶出的Fe(Ⅱ)活化PAA贡献26.46%的BPA降解,非均相ZVI活化PAA对BPA降解起主要作用;淬灭实验表明,ZVI/PAA体系存在CH_(3)C(O)OO·、CH_(3)C(O)O·、·OH和FeⅣO^(2+),其中CH_(3)C(O)OO·和FeⅣO^(2+)是降解BPA的主要活性物种。本研究可为工业废水中双酚A的有效去除提供理论和数据支撑。

Bisphenol A(BPA)is a representative pollutant in phenolic industrial wastewater.Zero valent iron(ZVI)was used to activate peroxyacetic acid(PAA)to remove BPA from water.The effects of ZVI and PAA dosage,pH value,and typical coexisting anions in industrial wastewater on PAA activation and BPA degradation were investigated,and the reaction mechanism of ZVI activation of PAA was analyzed by exploring the reactive species and active sites.Under the optimal process conditions of adding 50 mg/L ZVI,1.00 mmol/L PAA and an initial pH of 3.4,the ZVI/PAA system can remove 99.24%of BPA in water for 30 minutes.HCO_(3)^(-)and SO_(4)^(2-)showed inhibitory effects on BPA degradation,while Cl^(-)(0—20.0 mmol/L)accelerated the degradation of BPA in ZVI/PAA system.Soluble Fe(Ⅱ)and Fe(Ⅲ)were released from ZVI and its surface oxide layer,respectively,during the reaction.The released Fe(Ⅱ)activation of PAA contributed 26.46%of BPA degradation,while heterogeneous ZVI activation of PAA played a major role in BPA degradation.Scavenging experiment showed that CH_(3)C(O)OO·,CH_(3)C(O)O·,·OH and FeⅣO^(2+)were produced in ZVI/PAA system,among which CH_(3)C(O)OO·and FeⅣO^(2+)were the major reactive species contributing to BPA degradation.This study provided data and theoretical support for the effective removal of bisphenol A in industrial wastewater.