Co(Ⅱ)活化过一硫酸盐降解氨基三亚甲基膦酸的性能及反应机制  

Performance and Reaction Mechanism of Co(Ⅱ)Mediated Activation of Peroxymonosulfate for Degrading Nitrilotris(Methylene Phosphonic Acid)

作　　者：朱敬林[1,2] 汪舒 ZHU Jing-lin;WANG Shu(School of Earth and Environment,Anhui University of Science and Technology,Huainan 232001,China;State Key Laboratory of Pollution Control and Resource Reuse,School of Environment,Nanjing University,Nanjing 210023,China;School of Resources and Environmental Engineering,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]安徽理工大学地球与环境学院,淮南232001 [2]南京大学环境学院,污染控制与资源化国家重点实验室,南京210023 [3]合肥工业大学资源与环境工程学院,合肥230009

出　　处：《环境科学》2023年第7期3990-3996,共7页Environmental Science

基　　金：安徽省高校科学研究项目(KJ2021A0442);国家自然科学基金项目(22206003);安徽省自然科学基金项目(2208085QB63);污染控制与资源化研究国家重点实验室开放课题项目(PCRRF21040);安徽理工大学高层次引进人才科研启动基金项目(2021yjrc04)。

摘　　要：Co(Ⅱ)活化过一硫酸盐(PMS)能有效降解有机膦酸,但氨基有机膦酸的降解机制并不明确.以氨基三亚甲基膦酸(NTMP)为例,采用电子顺磁共振波谱(EPR)、自由基捕获实验和化学探针实验等探究其在Co(Ⅱ)/PMS体系下的降解机制,并分析了NTMP可能的降解路径和影响其降解的因素.结果表明,Co(Ⅱ)/PMS体系20 min内NTMP已经被完全降解,反应60 min后,78.3%NTMP被氧化生成正磷酸盐(PO_(4)^(3-)).^(1)O_(2)、HO·和SO_(4)^(-)·对Co(Ⅱ)/PMS体系氧化NTMP的贡献较小,Co(Ⅱ)-PMS络合物是NTMP降解的主要活性氧化物种.NTMP与Co(Ⅱ)-PMS络合物反应,使其C—N键和C—P键断裂生成多种含膦酸基团的中间产物,并最终被氧化为PO_(4)^(3-).随着PMS投加量和Co(Ⅱ)投加量的增加,NTMP氧化过程中PO_(4)^(3-)的产生率显著增加.此外,HCO3-和天然有机物(NOM)的存在显著抑制了Co(Ⅱ)/PMS体系PO_(4)^(3-)的产生.研究进一步完善了有机膦酸在Co(Ⅱ)/PMS体系下的氧化机制,为废水中有机膦酸的去除提供参考.Co(Ⅱ)mediated activation of peroxymonosulfate(PMS)could degrade phosphonate effectively,whereas the degradation of amino phosphonate remains unclear.Herein,nitrilotris(methylene phosphonic acid)(NTMP)was used as a target pollutant;the degradation mechanism was investigated using the electron paramagnetic resonance spectrum(EPR),free radical trapping experiments,and chemical probe experiments;and the possible degradation pathways of NTMP and the influencing factors were analyzed.The results showed that NTMP was completely degraded within 20 min in the Co(Ⅱ)/PMS system,and 78.3% of NTMP was oxidized to orthophosphate(PO_(4)^(3-))after 60 min of reaction.The Co(Ⅱ)-PMS complex was the main active oxidizing species,whereas 1O2,HO·,and SO_(4)^(-)·contributed little to the oxidation of NTMP in the Co(Ⅱ)/PMS system.A variety of intermediates containing phosphate groups were obtained through the breakage of the C—N bond and C—P bond as NTMP reacted with the Co(Ⅱ)-PMS complex and finally were oxidized to PO_(4)^(3-).With the increase in PMS dosage and Co(Ⅱ)dosage,the generation rate of PO_(4)^(3-)during the oxidation process of NTMP was significantly improved.In addition,the presence of HCO_(3)^(-)and natural organic matter(NOM)greatly inhibited the generation of PO_(4)^(3-)in the Co(Ⅱ)/PMS system.This study further improved the oxidation mechanism of phosphonate in the Co(Ⅱ)/PMS system and provides a reference for the removal of phosphonate in wastewater.

关 键 词：Co(Ⅱ) 过一硫酸盐(PMS) 氨基三亚甲基膦酸(NTMP) 正磷酸盐(PO_(4)^(3-)) 非自由基机制 

分 类 号：X703.1[环境科学与工程—环境工程]