研究报告
刘蕴晗,刘朝峰,李一兵,张娟娟,赵旭.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[J].环境科学学报,2022,42(5):247-253
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
- 基金项目: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)
- 刘蕴晗
- 河北工业大学,土木与交通学院,天津 300401;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
- 刘朝峰
- 河北工业大学,土木与交通学院,天津 300401
- 李一兵
- 河北工业大学,土木与交通学院,天津 300401
- 张娟娟
- 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
- 赵旭
- 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
- 摘要:针对化学镀镍废水中次磷酸盐(H2PO2-)难处理问题,采用次氯酸钠(NaClO)、过氧化氢(H2O2)、芬顿法、NaClO联用芬顿法对H2PO2-去除效果进行比较,发现NaClO可以有效提高芬顿法氧化H2PO2-的效率,并在适当条件下生成磷酸铁(FePO4)沉淀,实现磷的回收.同时,考察了NaClO浓度、H2O2浓度、溶液初始pH值、反应温度、共存有机阴离子柠檬酸根(C6H5O73-)和醋酸根(CH3COO-)浓度等条件对NaClO强化芬顿法处理H2PO2-反应体系的影响.结果表明,当H2PO2-初始浓度为1.0 mmol·L-1,Fe2+投加量为1.4 mmol·L-1,H2O2 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FePO4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H2PO2-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(1O2)、羟基自由基(?OH)、超氧自由基(?O2-)是体系中氧化H2PO2-的主要活性物种.
- Abstract:In view of the current treatment problem for hypophosphite (H2PO2-) in electroless nickel plating wastewater, the performance of H2PO2- removal with varies methods including sodium hypochlorite (NaClO), hydrogen peroxide (H2O2), Fenton, and NaClO combined with Fenton were compared. It was found that NaClO could effectively enhanced the oxidation efficiency of H2PO2- via Fenton process. Under certain conditions, phosphorus could be successfully recovered in the form of ferric phosphate (FePO4) precipitates. The effects of NaClO concentration, H2O2 concentration, initial solution pH, reaction temperature, coexisting organic anions citrate (C6H5O73-) and acetate (CH3COO-) concentration on H2PO2- 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 FePO4 precipitates at 60 min when the initial concentration of H2PO2- was 1.0 mmol·L-1, the dosage of Fe2+ was 1.4 mmol·L-1, the dosage of H2O2 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 C6H5O73- and CH3COO-. 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 (1O2), hydroxyl radical (?OH) and superoxide radical (?O2-) were the main active species on oxidation of H2PO2- in the constructed system.