Abstract:The cycling iodine extracting process from iodine enrichment waste water of acetic acid factory was analyzed on the view of thermodynamics. The effects on iodine reduction absorption rate were tested on the base of ascertaining the amount of reductant dosage, and analyzed theoretically. The results show that the blowing rate of iodine reaches 92%, the absorption rate reaches 85% or more and the refined iodine grade is over 99.5% under the following optimum conditions: height of padding of 40 cm, pH 6~7 and absorption temperature of 37 ℃.