Department of Chemical Engineering, University of Vigo, Isaac Newton Building, Campus As Lagoas Marcosende, 36310, Vigo, Spain.
Laboratoire Géomatériaux et Environnement (LGE), Université Paris-Est, EA 4508, 77454, Marne-la-Vallée, France.
Environ Sci Pollut Res Int. 2016 Oct;23(19):19134-44. doi: 10.1007/s11356-016-7054-x. Epub 2016 Jun 28.
The removal of radiocontrast agent diatrizoic acid (DIA) from water was performed using photo-Fenton (PF) process. First, the effect of H2O2 dosage on mineralization efficiency was determined using ultraviolet (UV) irradiation. The system reached a maximum mineralization degree of 60 % total organic carbon (TOC) removal at 4 h with 20 mM initial H2O2 concentration while further concentration values led to a decrease in TOC abatement efficiency. Then, the effect of different concentrations of Fenton's reagents was studied for homogeneous Fenton process. Obtained results revealed that 0.25 mM Fe(3+) and 20 mM H2O2 were the best conditions, achieving 80 % TOC removal efficiency at 4 h treatment. Furthermore, heterogeneous PF treatment was developed using iron-activated carbon as catalyst. It was demonstrated that this catalyst is a promising option, reaching 67 % of TOC removal within 4 h treatment without formation of iron leachate in the medium. In addition, two strategies of enhancement for process efficiency are proposed: coupling of PF with electro-Fenton (EF) process in two ways: photoelectro-Fenton (PEF) or PF followed by EF (PF-EF) treatments, achieving in both cases the complete mineralization of DIA solution within only 2 h. Finally, the Microtox tests revealed the formation of more toxic compounds than the initial DIA during PF process, while, it was possible to reach total mineralization by both proposed alternatives (PEF or PF-EF) and thus to remove the toxicity of DIA solution.
使用光芬顿（PF）工艺去除水中的造影剂二碘酸（DIA）。首先，通过紫外线（UV）照射确定 H2O2 剂量对矿化效率的影响。该系统在 4 小时内达到最大矿化度，初始 H2O2 浓度为 20 mM，总有机碳（TOC）去除率为 60%，而进一步增加浓度值会降低 TOC 去除效率。然后，研究了不同浓度的芬顿试剂对均相芬顿过程的影响。获得的结果表明，0.25 mM Fe(3+)和 20 mM H2O2 是最佳条件，在 4 小时处理下可达到 80%的 TOC 去除效率。此外，使用铁活性炭作为催化剂开发了非均相 PF 处理。结果表明，该催化剂是一种很有前途的选择，在 4 小时处理内可去除 67%的 TOC，而不会在介质中形成铁浸出物。此外，提出了两种提高工艺效率的策略：以两种方式将 PF 与电芬顿（EF）工艺耦合：光电芬顿（PEF）或 PF 后接 EF（PF-EF）处理，在这两种情况下，DIA 溶液都在仅 2 小时内完全矿化。最后，Microtox 测试表明，PF 过程中形成的有毒化合物比初始 DIA 更多，而通过两种提出的替代方法（PEF 或 PF-EF）都可以达到完全矿化，从而消除 DIA 溶液的毒性。
