Surface oxidation for reducing ammonia and hydrogen sulfide emissions from dairy manure storage

Abstract

Surface oxidation for reducing ammonia and hydrogen sulfide emissions from dairy manure was studied in a laboratory. Ammonia and hydrogen sulfide emissions from manure storages were measured. Total ammonia, pH, dissolved sulfide concentrations, and chemical oxygen demand of the manure were monitored, and overall mass transfer coefficients of ammonia and hydrogen sulfide were calculated. Spraying 0.5% hydrogen peroxide on the manure surface not only steadily reduced 70% of the ammonia emissions, but also significantly reduced the ammonia concentration on the liquid manure surface. This reduction in ammonia emissions may be partially due to the reduced ammonia concentration and partially due to the decreased pH on the manure surface. Spraying 0.5% potassium permanganate on the manure surface initially reduced ammonia emissions by 70%, but gradually became less effective. Spraying hydrogen peroxide and potassium permanganate on the manure surface also reduced hydrogen sulfide emissions. The results also indicated that the overall mass transfer coefficients of ammonia and hydrogen sulfide were not affected by the spraying of oxidant on the liquid surface. In terms of the effectiveness in reducing ammonia and hydrogen sulfide emissions and the residue left in the treated manure, hydrogen peroxide was superior to potassium permanganate for this application.