Odors in wastewater are caused chiefly by the products of the anaerobic reduction of organic nitrogen and sulfur-containing compounds. Hydrogen sulfide (H2S) is a major component of wastewater odors. Oxidation with chlorine is one method of removing odors and it has the added benefit of killing the microorganisms responsible for the generation of H2S in the first place. As a specific example, HOCl reacts with H2S as follows in low pH solutions
HOCl + H2S <--> S + HCl + H2O
If the actual plant practice calls for 100% excess HOCl (to make sure of the destruction of
H2S because of the reaction of HOCl with other substances), what volume of HOCl (5 wt% solution) must be added to 1 L of a solution containing 50 ppm H2S? You may assume that the density of the HOCl solution and the solution containing H2S are the same as water.