Farm-scale testing of soybean peroxidase and calcium peroxide for surficial swine manure treatment and mitigation of odorous VOCs, ammonia and hydrogen sulfide emissions

Abstract

The swine industry, regulatory agencies, and the public are interested in farm-tested methods for controlling gaseous emissions from swine barns. In earlier lab-and pilot-scale studies, a renewable catalyst consisting of soybean peroxidase (SBP) mixed with calcium peroxide (CaO 2) was found to be effective in mitigating gaseous emissions from swine manure. Thus, a farm-scale experiment was conducted at the university's 178-pig, shallow-pit, mechanically-ventilated swine barn to evaluate SBP/CaO 2 as a surficial manure pit additive under field conditions. The SBP was applied once at the beginning of the 42-day experiment at an application rate of 2.28 kg m −2 with 4.2% CaO 2 added by weight. Gas samples were collected from the primary barn exhaust fans. As compared to the control, significant reductions in gaseous emissions were observed for ammonia (NH 3 , 21.7%), hydrogen sulfide (H 2 S, 79.7%), n-butyric acid (37.2%), valeric acid (47.7%), isovaleric acid (39.3%), indole (31.2%), and skatole (43.5%). Emissions of dimethyl disulfide/ methanethiol (DMDS/MT) increased by 30.6%. Emissions of p-cresol were reduced by 14.4% but were not statistically significant. There were no significant changes to the greenhouse gas (GHG) emissions of methane (CH 4), carbon dioxide (CO 2) and nitrous oxide (N 2 O). The total (material + labor) treatment cost was $2.62 per marketed pig, equivalent to 1.5% of the pig market price. The cost of CaO 2 catalyst was ∼60% of materials cost. The cost of soybean hulls (SBP source) was $0.60 per marketed pig, i.e., only 40% of materials cost.

Evaluation of Semi-Continuous Pit Manure Recharge System Performance on Mitigation of Ammonia and Hydrogen Sulfide Emissions from a Swine Finishing Barn

“…The source-based approaches can manage emissions at the odor source, usually addressing emissions from manure. Various topical additives to swine manure surface such as biochar [26], soybean peroxidase [27,28], and poultry manure such as zeolites [29], and bioactive sorbents [30] have been tested. Because swine barn odor is mainly caused by emissions from manure [31], the source-based methods are aimed at proper manure management.…”

VOC Removal from Manure Gaseous Emissions with UV Photolysis and UV-TiO2 Photocatalysis

“…Odor, VOCs, GHGs, NH 3 and H 2 S mitigation technologies for livestock operations have been reviewed [21]. The main approaches for livestock housing include barriers, biofiltration, chimneys, diet modification, electrostatic precipitation, landscaping, oil sprinkling, manure pit additives and ventilation, scrubbers, siting, and setbacks, urine/feces separation, and UV light [22][23][24][25][26][27][28][29][30]. To date, however, these technologies, save for biofilters and scrubbers, have a limited on-farm implementation and performance record in the U.S. due to complex regulatory and socioeconomic factors.…”

The Impact of Biochar Treatment on H2S and NH3 Emissions During Manure Agitation prior to Pump-Out

“…Still, sciencebased guides as well as more data are needed to evaluate manure additive effectiveness on the mitigation of gases emitted from storage (Maurer et al, 2016). From recent studies, manure additives such as soybean peroxidase, zeolite, and biochar show the effectiveness of mitigating NH3, H2S, VOCs, and GHG emissions from swine manure (Maurer et al, 2017a(Maurer et al, , 2017b(Maurer et al, , 2017cParker et al, 2016;Cai et al, 2007;Kalus, 2017). Additionally, in our recent research, we evaluated numerous commercial manure additives for gaseous emissions mitigation, but there are no statistically significant findings (Chen, 2019).…”