多羟基亚铁耦合臭氧同步去除重金属和有机物——以Cu(Ⅱ)-EDTA去除为例  

Simultaneous Removal of Heavy Metals and Organic Matter by Ferrous Hydroxyl Complex Coupled with Ozone:A Case Study of Cu(Ⅱ)-EDTA Removal

作　　者：邰伟 叶国杰 何群彪[1] 吴德礼[1] TAI Wei;YE Guojie;HE Qunbiao;WU Deli(College of Environmental Science and Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学环境科学与工程学院,上海200092

出　　处：《能源环境保护》2025年第1期113-126,共14页Energy Environmental Protection

基　　金：国家自然科学基金资助项目(52170091,42377390)。

摘　　要：重金属-有机络合物废水因其难以被生物降解,是工业废水治理的重要难题之一。首次提出采用还原和络合能力更强的多羟基结构态亚铁(FHC)还原破络Cu(Ⅱ)-EDTA以去除铜。利用原位生成的CuFe_(2)O_(4)、Cu_(2)O等活性金属催化臭氧(O_(3))生成·OH,促进有机配体的完全矿化,最终实现重金属和有机配体的同步去除。在优化条件下,当FHC的[Fe^(2+)]∶[OH^(-)]配比为1∶3,投加量为2 mmol/L,O_(3)剂量为10 mg/min时,可在60 min内将0.2 mmol/L Cu(Ⅱ)-EDTA中的铜和有机配体完全去除,且无残留铁存在。当[FHC(1∶3)]∶[Cu(Ⅱ)-EDTA]高于5∶1时,可确保铜被完全破络去除,并且通过提高FHC中[OH^(-)]的比例,而非增加FHC投加量,可以提高Cu(Ⅱ)-EDTA破络去除的经济性。研究表明,该工艺不.受Cl^(-)、NO_(3)^(-)、SO _(4)^(2-)等常见阴离子的影响,具备良好的抗环境干扰能力。破络后原位生成的CuFe_(2)O_(4)、Cu_(2)O以及臭氧催化氧化后形成的Fe_(3)O_(4)均具有磁性,具备磁力分离的潜力。电子自旋共振(EPR)结果证实了原位生成产物可催化O_(3)产生·OH、1O_(2)和·O _(2)^(-)。淬灭实验结果显示,加入叔丁醇(TBA)后EDTA的去除率从100.0%降至57.7%,间接证明·OH参与了EDTA的降解。基于LC-MS的分析结果证明,FHC还原破络Cu(Ⅱ)-EDTA形成乙二胺四乙酸铁(Fe-EDTA),通入O_(3)后,Fe-EDTA中的N—C键被·OH和O_(3)破坏,连续脱羧形成三乙酸乙二胺铁(Fe-ED3A)、二乙酸乙二胺铁(Fe-ED2A)、甘氨酸、次氮基三乙酸铁(FeNTA)和次氮基三乙酸(NTA)等中间产物,或进一步通过乙酸基团取代形成亚胺二乙酸铁(FeIMDA)和亚胺二乙酸(IMDA),并最终矿化为CO_(2)和H_(2)O。该技术对于重金属-有机络合物废水治理具有借鉴参考意义。Heavy metal-organic complexes in industrial wastewater pose significant challenges due to their resistance to biological treatment.This study proposes the use of ferrous hydroxyl complex(FHC)to break down copper ethylenediaminetetraacetate(Cu(Ⅱ)-EDTA)and remove copper,leveraging its strong reduction and complexation capabilities.The process involves in situ generation of CuFe_(2)O_(4) and Cu_(2)O from the reduction of Cu(Ⅱ)-EDTA by FHC.These active metal species catalyze the production of hydroxyl radicals(·OH)from ozone(O3),promoting the further mineralization of organic ligands and achieving synchronous removal of heavy metals and organic ligands.Under optimized conditions,the[Fe^(2+)]∶[OH-]ratio of FHC is 1∶3,with a dosage of 2 mmol/L for FHC and 10 mg/min for O_(3).This allows the complete removal of 0.2 mmol/L Cu(Ⅱ)-EDTA within 60 minutes,with no residual dissolved iron.A ratio of[FHC(1∶3)]∶[Cu(Ⅱ)-EDTA]exceeding 5∶1 ensures complete decomplexation and removal of copper.The economic efficiency of Cu(Ⅱ)-EDTA decomplexation and removal can be enhanced by increasing the proportion of[OH-]in FHC rather than increasing the dosage of FHC.The process exhibits strong resistance to common anions such as chloride(Cl-),nitrate NO-3 SO2-4(),and sulfate,indicating its practical applicability in diverse wastewater.The in situ generated CuFe_(2)_(O4),Cu_(2)O,and Fe_(3)O_(4) after ozonation are magnetic,offering potential for magnetic separation and further enhancing cost-effectiveness.To validate the mechanism,electron paramagnetic resonance(EPR)analysis was conducted.The results confirmed that the in situ generated products can effectively catalyze the production of hydroxyl radicals(·OH),singlet oxygen(1O_(2)),and superoxide·O_(2)^(-)radicals from O_(3).Quenching experiments were performed to investigate the role of reactive oxidative species(ROS)in the degradation of EDTA.The results showed that the removal rate of EDTA decreased from 100.0% to 57.7%upon the addition of tert-butanol(TBA),indirectly

关 键 词：原位催化 多羟基结构态亚铁 臭氧催化氧化 重金属-有机络合物 同步去除 

分 类 号：X703[环境科学与工程—环境工程]