Low-Dose Acidification as a Methane Mitigation Strategy for Manure Management

Excreta from housed animals are typically stored before land application, and storage is an important point source of CH4, N gases, odor. This study explored acidification as a strategy for greenhouse gas (GHG) mitigation, specifically the potential to reduce acid dose improve cost-effectiveness minimize environmental impacts. Pig slurry was with five doses concentrated sulfuric [1.2–6.0 kg (m3 slurry)−1] 63 days. Emissions CH4 NH3 were reduced by 46–96% 33–78%, respectively, increase in dose. Odorant emissions, dominated 4-methyphenol H2S, strongly suppressed acidification. Below pH 6, methanogen inhibition most likely due undissociated VFAs, above could involve competition sulfate reducers H2S. If 1, 3, or 10 treatments needed, annual costs GHG mitigation across 28–47, 44–57, 93–134 € (ton CO2 equivalents)−1, respectively. With 1 3 treatments, cost-effective 2.1 m–3, 3.2 m–3 treatments. suggests that low-dose viable mitigation.