UV/Fe(Ⅲ)工艺是一种处理络合态重金属的新型组合工艺，该工艺先通过Fe(Ⅲ)的置换作用释放游离重金属离子，然后通过UV辐照对有机配体进行降解，最后通过碱性沉淀去除络合态重金属。以Cu(Ⅱ)-EDTA、Ni(Ⅱ)-EDTA为目标污染物，采用UV/Fe(Ⅲ)工艺对其进行去除，通过去除效果对比和机理分析，对组合工艺去除效果差异的内部机理进行阐述，并提出相应的优化方案。结果表明，UV/Fe(Ⅲ)工艺对Cu(Ⅱ)-EDTA、Ni(Ⅱ)-EDTA的去除效果存在较大差异，对两种络合态重金属中Cu、Ni的去除率分别为70%和41%。通过高效液相色谱（HPLC）、分光光度法、苯甲酸（BA）探针实验，确定Cu(Ⅱ)-EDTA、Ni(Ⅱ)-EDTA去除效果差异的主要原因是Fe(Ⅲ)对Cu(Ⅱ)、Ni(Ⅱ)的置换效果有明显差异，置换率分别是85%、22%。对Ni(Ⅱ)-EDTA置换过程分别进行Fe(Ⅲ)投加量和反应温度优化，结果表明，反应温度优化可以显著提升Fe(Ⅲ)对Ni(Ⅱ)-EDTA的置换效率。将反应温度提升至35 ℃，Ni去除率从41%提升至60%。反应温度在UV/Fe(Ⅲ)工艺中对Ni(Ⅱ)-EDTA的去除至关重要，适当升温有助于提高置换率，进而提升去除率。

The UV/Fe(Ⅲ) process is a new combined process for treating heavy metal complexes. This process first releases free metal ions through the replacement of Fe(Ⅲ), then, it degraded the organic ligands via UV irradiation, and finally, heavy metals were removed by alkaline precipitation. In this study, heavy metal complexes, Cu(Ⅱ)-EDTA and Ni(Ⅱ)-EDTA, were removed by UV/Fe(Ⅲ) process. Through the comparison of removal effects and mechanism analysis, the internal mechanism of the difference in removal effects of the combined process was described, and the corresponding optimization scheme was proposed. The results showed that the removal efficiency of Cu(Ⅱ)-EDTA and Ni(Ⅱ)-EDTA was quite different, and the removal rates of Cu and Ni were 70% and 41%, respectively. The main reason for the difference in removal efficiency between Cu(Ⅱ)-EDTA and Ni(II)-EDTA was determined through high-performance liquid chromatography (HPLC), spectrophotometric analysis, and benzoic acid (BA) probe experiments, showing that Fe(Ⅲ) had a noticeable difference in displacing Cu(Ⅱ) and Ni(Ⅱ), with replacement rates of 85% and 22%, respectively. Optimal Fe(Ⅲ) dosages and reaction temperatures were separately optimized for the Ni(Ⅱ)-EDTA replacement process. The results showed that the reaction temperature optimization can significantly improve the Fe(Ⅲ) displacement efficiency on Ni(Ⅱ)-EDTA. When the reaction temperature was increased to 35 ℃, the removal efficiency of Ni was increased from 41% to 60%. The reaction temperature is very important for the removal of Ni(Ⅱ)-EDTA by UV/Fe(Ⅲ) process, proper heating is helpful to increase the replacement rate and further improve the removal efficiency.

X703.1

国家自然科学基金（42007314）；国家重点研发计划（2022YFC3901302）