Method for oxidizing iodide ions into iodate by using ferrate and controlling generation of iodo-disinfection byproducts in water

Abstract

The invention discloses a method for oxidizing iodide ions into iodate by using ferrate and controlling generation of iodo-disinfection byproducts in water, and relates to the field of water treatmentmethods. The purpose of the invention is to solve the problem of the iodo-disinfection byproducts formed by iodide ions and natural organic matters existing in water during treatment in a traditionaldisinfection mode. The method comprises the following steps: adding the ferrate into a water source containing iodide ions, and carrying out an oxidation reaction to complete the method. Potassium ferrate is used as a strong oxidant to rapidly oxidize iodine ions in water into hypoiodic acid, and when the concentration of the hypoiodic acid in the system is accumulated to the maximum value, the hypoiodic acid is gradually oxidized into iodate by the potassium ferrate, so that the concentration of the hypoiodic acid is reduced, and the possibility that the hypoiodic acid reacts with organic matters to generate the iodo-disinfection byproducts is reduced. The increase of the concentration of potassium ferrate can promote the conversion of iodide ions and hypoiodic acid into iodate, the generation amount of the iodo-disinfection byproducts is small, and the method is suitable for large-scale application. The method is used for treating the iodine ion-containing water source.

Description

technical field

[0001] The invention relates to the field of water treatment methods. Background technique

[0002] A large number of animal experiments have shown that trihalomethanes are teratogenic, carcinogenic and mutagenic. If the trihalomethanes in animals reach a certain concentration, it may cause intestinal, kidney and liver tumors. Among the halogenated DBPs, the iodo-DBPs showed greater toxicity than the chlorine-bromine DBPs. Iodine products are mainly produced during the disinfection process: in the process of disinfecting iodized water, iodide ions will be oxidized by chlorine and chloramine and other disinfectants into hypoiodous acid with a certain oxidizing ability. Hypoiodous acid can be converted through three paths: the first is to oxidize hypoiodous acid to non-toxic iodate through the continuous oxidation of disinfectants; the second is to decompose into non-toxic iodate through self-disproportionation reaction of hypoiodous Toxic and harmless iodid...