School of Environment, Liaoning University, Shenyang 110036, China.
Molecules. 2021 Oct 28;26(21):6527. doi: 10.3390/molecules26216527.
Iopromide (IOP), an iodinated X-ray contrast medium (ICM), is identified as a precursor to iodide disinfection byproducts that have high genotoxicity and cytotoxicity to mammals. ICM remains persistent through typical wastewater treatment processes and even through some hydroxyl radical-based advanced oxidation processes. The development of new technologies to remove ICMs is needed. In this work, mackinawite (FeS)-activated sulfite autoxidation was employed for the degradation of IOP-containing water. The experiment was performed in a 500 mL self-made temperature-controlled reactor with online monitoring pH and dissolved oxygen in the laboratory. The effects of various parameters, such as initial pH values, sulfite dosages, FeS dosages, dissolved oxygen, and inorganic anions on the performance of the treatment process have been investigated. Eighty percent of IOP could be degraded in 15 min with 1 g L FeS, 400 μmol L sulfite at pH 8, and high efficiency on the removal of total organic carbon (TOC) was achieved, which is 71.8% via a reaction for 1 h. The generated hydroxyl and oxysulfur radicals, which contributed to the oxidation process, were identified through radical quenching experiments. The dissolved oxygen was essential for the degradation of IOP. The presence of Cl could facilitate IOP degradation, while NO and CO could inhibit the degradation process. The reaction pathway involving H-abstraction and oxidative decarboxylation was proposed, based on product identification. The current system shows good applicability for the degradation of IOP and may help in developing a new approach for the treatment of ICM-containing water.
碘普罗胺（IOP），一种含碘的 X 射线造影剂（ICM），被认为是碘化物消毒副产物的前体，这些副产物对哺乳动物具有高遗传毒性和细胞毒性。ICM 通过典型的废水处理工艺甚至一些基于羟基自由基的高级氧化工艺仍然存在。需要开发去除 ICM 的新技术。在这项工作中，采用 mackinawite（FeS）激活亚硫酸盐自氧化法降解含 IOP 的水。实验在一个 500 毫升的自制控温反应器中进行，实验室在线监测 pH 和溶解氧。研究了各种参数对处理过程性能的影响，如初始 pH 值、亚硫酸盐用量、FeS 用量、溶解氧和无机阴离子。在 1 g L FeS、400 μmol L 亚硫酸盐和 pH 8 的条件下，15 分钟内可降解 80%的 IOP，TOC 的去除效率很高，反应 1 小时后可达 71.8%。通过自由基猝灭实验鉴定了生成的羟基和过氧硫自由基，它们对氧化过程有贡献。溶解氧是 IOP 降解的必要条件。Cl 的存在可以促进 IOP 的降解，而 NO 和 CO 可以抑制降解过程。根据产物鉴定，提出了涉及 H 提取和氧化脱羧的反应途径。该系统在降解 IOP 方面表现出良好的适用性，可能有助于开发处理含 ICM 水的新方法。
