Minimizing chlorate ion formation

Abstract

Storage tanks that contain liquod bleach should be periodically flushed and cleaned to minimize buildup of a residual chlorate ion concentration.The treatment of drinking water with either NaOCl or Ca(OCl)₂ is a source of chlorate ion (ClO₃⁻) in finished water. In basic solution, liquid bleach (NaOCl) decomposition is a second‐order process. The decomposition of OCl⁻ involves chlorite ion (ClO₂⁻) as a low‐concentration intermediate. The reaction of ClO₂⁻ to form ClO₃⁻ is a fast process, and the ClO₂⁻ in liquid bleach is at a concentration at least 200 times less than the OCl⁻ concentration. The formation of oxygen from decomposing OCl⁻ is a slower side reaction (<10 percent).