H2S Control and Removal

Complete removal of H2S can best be accomplished by oxidation by chlorine; conversion of chlorine, resulting colloidal sulfur and polysulfides by metabisulfite or sulfur dioxide to thiosulfates, and then converting to sulfates by rechlorination.

Filtronics series of reaction vessels takes advantage of this mechanism by insuring break point chlorination and carrying a 0.5 mg/l free chlorine residual to the distribution system for disinfection and sulfur bacteria control. The reaction is begun in the first reaction vessel where all the forms of sulfur are produced. Between the first and second reaction vessel, sulfite is added where the thiosulfate is then formed. The thiosulfate oxidizes very rapidly producing a sulfate and a sulfite. Thus another sulfite is available to continue the conversion of any sulfur or polysulfides. By going to breakpoint and carrying a free residual through the system, re-chlorination is not necessary. 

For more information, check out our H2S Technical Bulletin at http://bit.ly/1cidoY4