Coagulation of Iodide-Containing Resorcinol Solution or Natural Waters with Ferric Chloride Can Produce Iodinated Coagulation Byproducts Shunke Ding Yang Deng Hongwei Li Chao Fang Naiyun Gao Wenhai Chu 10.1021/acs.est.9b03671.s001 https://acs.figshare.com/articles/journal_contribution/Coagulation_of_Iodide-Containing_Resorcinol_Solution_or_Natural_Waters_with_Ferric_Chloride_Can_Produce_Iodinated_Coagulation_Byproducts/9956501 Iodinated disinfection byproducts (I-DBPs) are of particular concern in drinking water due to the more cytotoxic and genotoxic properties than their chlorinated and brominated analogs. Formation of I-DBP primarily results from the oxidation of iodide-containing waters with various oxidants and the chlor­(am)­ination of iodinated organic compounds in drinking water. This study first reports that ferric chloride (FeCl<sub>3</sub>) can lead to the formation of iodinated coagulation byproducts (I-CBPs) from iodide-containing resorcinol solution or natural waters. The unwanted I-CBP formation involved the oxidation of iodide by ferric ions to generate various reactive iodine species, which further oxidize organic compounds. Although the oxidation rate of iodide by FeCl<sub>3</sub> was several orders of magnitude slower than that by chlorine or chloramine, most of the converted iodide under the ferric/iodide system was transformed into iodine and iodinated organic compounds rather than iodate. Formation of four aliphatic I-CBPs was observed, and four aromatic I-CBPs were identified by gas chromatography mass-spectrometry and theoretical calculation. Coagulation of iodide-containing waters with FeCl<sub>3</sub> also produced I-CBPs ranging from 12.5 ± 0.8 to 32.5 ± 0.2 μg/L as I. These findings call for careful consideration of the formation of I-CBPs from coagulation of iodide-containing waters with ferric salts. 2019-10-08 21:16:07 Coagulation compound I-CBP iodide-containing resorcinol solution oxidation drinking water formation FeCl 3 I-DBP reactive iodine species ferric gas chromatography mass-spectrometry iodide-containing waters Iodide-Containing Resorcinol Solution