次氯酸钠强化芬顿法处理废水中次磷酸盐同步回收磷酸铁  

NaClO-enhanced Fenton process for oxidation of hypophosphite and simultaneous recovery of ferric phosphate

作　　者：刘蕴晗 刘朝峰 李一兵 张娟娟[2] 赵旭[2] LIU Yunhan;LIU Chaofeng;LI Yibing;ZHANG Juanjuan;ZHAO Xu(School of Civil and Transportation Engineering,Hebei University of Technology,Tianjin 300401;Key Laboratory of Drinking Water Science and Technology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085)

机构地区：[1]河北工业大学,土木与交通学院,天津300401 [2]中国科学院生态环境研究中心,饮用水科学与技术重点实验室,北京100085

出　　处：《环境科学学报》2022年第5期247-253,共7页Acta Scientiae Circumstantiae

基　　金：中国博士后科学基金(No.2020M680710);国家自然科学基金(No.21777176);贵州省科技计划项目(黔科合支撑[2021]一般472,黔科合支撑[2019]2848号)。

摘　　要：针对化学镀镍废水中次磷酸盐(H_(2)PO_(2)^(-))难处理问题,采用次氯酸钠(NaClO)、过氧化氢(H_(2)O_(2))、芬顿法、NaClO联用芬顿法对H_(2)PO_(2)^(-)去除效果进行比较,发现NaClO可以有效提高芬顿法氧化H_(2)PO_(2)^(-)的效率,并在适当条件下生成磷酸铁(FePO_(4))沉淀,实现磷的回收.同时,考察了NaClO浓度、H_(2)O_(2)浓度、溶液初始pH值、反应温度、共存有机阴离子柠檬酸根(C_(6)H_(5)O_(7)^(3-))和醋酸根(CH_(3)COO-)浓度等条件对NaClO强化芬顿法处理H_(2)PO_(2)^(-)反应体系的影响.结果表明,当H_(2)PO_(2)^(-)初始浓度为1.0 mmol·L^(-1),Fe^(2+)投加量为1.4 mmol·L^(-1),H_(2)O_(2)投加量为4.0 mmol·L^(-1),NaClO投加量为20.0 mmol·L^(-1),初始溶液pH为3.0时,反应60 min后,总磷的去除率高达90%,且去除的磷以FePO_(4)沉淀形式被回收.温度升高有利于反应效果的提升,柠檬酸根和醋酸根的存在对总磷的去除有抑制作用.进一步研究了NaClO强化芬顿法体系处理H_(2)PO_(2)^(-)的反应机制.自由基淬灭实验和电子自旋共振波谱(ESR)分析证明,单线态氧(^(1)O_(2))、羟基自由基(•OH)、超氧自由基(•O2-)是体系中氧化H_(2)PO_(2)^(-)的主要活性物种.In view of the current treatment problem for hypophosphite(H_(2)PO_(2)^(-))in electroless nickel plating wastewater,the performance of H_(2)PO_(2)^(-)removal with varies methods including sodium hypochlorite(NaClO),hydrogen peroxide(H_(2)O_(2)),Fenton,and NaClO combined with Fenton were compared.It was found that NaClO could effectively enhanced the oxidation efficiency of H_(2)PO_(2)^(-)via Fenton process.Under certain conditions,phosphorus could be successfully recovered in the form of ferric phosphate(FePO_(4))precipitates.The effects of NaClO concentration,H_(2)O_(2) concentration,initial solution pH,reaction temperature,coexisting organic anions citrate(C_(6)H_(5)O_(7)^(3-))and acetate(CH_(3)COO^(-))concentration on H_(2)PO_(2)^(-)removal in the constructed NaClO-enhanced system were investigated.The results indicated that the removal efficiency of total phosphorus(TP)was 90%and TP was recovered in the form of FePO_(4) precipitates at 60 min when the initial concentration of H_(2)PO_(2)^(-)was 1.0 mmol·L^(-1),the dosage of Fe2+was 1.4 mmol·L^(-1),the dosage of H_(2)O_(2) was 4.0 mmol·L^(-1),the dosage of NaClO was 20.0 mmol·L^(-1),and the initial solution pH was 3.0.It was proved that the high temperature was favorable for the recovery of TP.The removal of TP was obviously inhibited in the presence of C_(6)H_(5)O_(7)^(3-)and CH_(3)COO^(-).Moreover,the mechanism in the constructed NaClO-enhanced Fenton system was investigated.The radical quenching experiments and electron spin resonance(ESR)spectroscopy results indicated that singlet oxygen(^(1)O_(2)),hydroxyl radical(•OH)and superoxide radical(•O2−)were the main active species on oxidation of H_(2)PO_(2)^(-)in the constructed system.

关 键 词：次磷酸盐氧化 次氯酸钠 芬顿法 磷回收 

分 类 号：X703[环境科学与工程—环境工程]