Efficacy of Different Nanoparticles in Mitigating Gaseous Emissions from Liquid Dairy Manure Stored Under Anaerobic Condition

Abstract. A number of mitigation techniques exist to reduce the emissions of pollutant gases and greenhouse gasses (GHGs) from anaerobic storage of livestock manure. Application of nanoparticles (NPs) to livestock manure is a potential mitigation option. In this study, several NPs such as Zinc Silica Nanogel, Copper Silica Nanogel, and N-Acetyl Cysteine coated Zinc Oxide Qdots, all in liquid formulation along with the control (without any NP addition) treatment were tested in dairy manure stored under anaerobic conditions. All experiments were conducted in batches with three replications at a dose of 3 gL^-1 in a 1-L Erlenmeyer flask with a working volume of 500 mL. Headspace gas from each of the Tedlar bags was collected at 2-14 days‘ interval through the 56 days of the experimental period and analyzed for methane (CH₄) and carbon dioxide (CO₂) gas concentrations using SRI-8610 Gas Chromatograph. Hydrogen sulfide (H₂S) concentrations were measured by using the Jerome 631X meter. Nanoparticles tested in this study reduced the cumulative gas volume by 80.55-98.60% and in terms of H₂S and GHGs concentration the reduction percentages were between 48.98-99.86% compared to the control. Thus, application of NPs is a potential treatment option for mitigating pollutant and GHG emissions from anaerobic storage of manure and this can be implemented to control gaseous emissions from other sources.