Reducing odorous VOC emissions from swine manure using soybean peroxidase and peroxides

The objective of the research was to determine the optimum application rates of soybean peroxidase (SBP) plus peroxide (SBPP) for reducing odorous VOC emissions from swine manure. Industrial-grade SBP was applied in combination with liquid hydrogen peroxide (H2O2) or powdered calcium peroxide (CaO2) to standard phenolic solutions and swine manure, and emissions were measured in a wind tunnel. The primary odorant in the untreated manure was 4-methylphenol, which accounted for 68-81% of the odor activity value. At the optimum application rate of SBPP (50 g L-1), 4-methylphenol emissions were reduced from the swine manure by 62% (H2O2) and 98% (CaO2) after 24 h (P < 0.0001). The CaO2 had a longer residence time, remaining effective for 48 h with 92% reduction in emission rates (P < 0.0001), while H2O2 was similar to the control at 48 h (P = 0.28). (C) 2012 Elsevier Ltd. All rights reserved.