Iodinated X-ray contrast media (ICM) is considered as one of iodine sources for formation of toxic iodinated disinfection byproducts (I-DBPs) during disinfection. This study investigated transformation of a typical ICM, iopamidol (IPM) by zero valent iron (ZVI) and the effect of transformation on the formation of I-DBPs during chloramination. It was found that the presence of ZVI could deiodinate IPM into I⁻ and the transformation of IPM exhibited a pseudo-first-order kinetics. Acidic circumstance, SO₄²⁻, Cl⁻ and monochloramine could promote the transformation of IPM by ZVI, while SiO₃²⁻ inhibited the transformation of IPM. Moreover, the transformation of IPM by ZVI changed both the formed species and amounts of I-DBPs during chloramination. During the chloramination of IPM-containing water, CHCl₂I and iodoacetic acid were the predominant iodinated trihalomethanes (I-THMs) and iodinated haloacetic acids (I-HAAs), respectively in the absence of ZVI, while CHI₃ and triiodoacetic acid became the predominant ones with 1.0 g L⁻¹ ZVI. The addition of 5.0 g L⁻¹ ZVI increased I-DBPs formation amounts by 6.0 folds after 72 h and maximum formation of I-DBPs occurred at pH 5.0. Enhanced I-DBPs formation was also observed with various real water sources. Given that ZVI ubiquitously exists in the unlined cast iron distribution pipes, the deiodination of IPM by ZVI during distribution may increase the formation of I-DBPs, which needs receive enough attention.

碘化X射线造影剂（ICM）被认为是在消毒过程中形成有毒碘化消毒副产物（I-DBPs）的碘源之一。这项研究调查了零价铁（ZVI）对典型ICM碘帕（IPM）的转化以及在氯化过程中转化对I-DBPs形成的影响。发现ZVI的存在可以将IPM去碘化为I- ^，并且IPM的转化表现出伪一级动力学。酸性环境，SO ₄ ^2-，氯^-和一氯胺能促进IPM的零价铁的转变，而二氧化硅₃ ^2-抑制了IPM的转化。此外，ZVI对IPM的转化同时改变了氯化过程中I-DBP的形成种类和数量。在含IPM的水氯化过程中，在没有ZVI的情况下，CHCl ₂ I和碘乙酸分别是主要的碘化三卤甲烷（I-THMs）和碘化卤代乙酸（I-HAAs），而CHI ₃和三碘乙酸成为主要是1.0 g L ^-1 ZVI。5.0 g L ^-1的添加ZVI在72小时后使I-DBPs的形成量增加了6.0倍，并且在pH 5.0时I-DBPs的形成量最大。在各种实际水源中也观察到I-DBPs形成的增强。由于无衬里铸铁配电管中普遍存在ZVI，因此ZVI在配电过程中对IPM的脱碘作用可能会增加I-DBP的形成，因此需要引起足够的重视。