Mitigation of NH emission from pig house using a rice husk biochar column and fertilizer potential of collected biochar.

NH emissions have significant implications for ecosystems and human health. Pig houses are important sources of NH emissions. This study aimed to evaluate the NH adsorption capacity of rice husk biochar (RHB), its effectiveness in mitigating NH emission from pig house using a RHB column, and the fertilizer potential of the collected RHB for maize growth. In a laboratory assay, NH adsorption by RHB was measured using a closed chamber where NH was diffused from NHOH. NH adsorption in RHB packed in column was the highest at a flow rate of 2.0 L min (6.52 mg g). HSO-mixed RHB enhanced NH adsorption by 41.7% compared to RHB alone. When compared the efficiency of RHB column in NH emission, the emission reduced by 34.5% and 58.2%, respectively, after passing RHB and HSO-mixed RHB columns compared to that measured without column (0.59 g d). In a pig house setting, NH concentration after passing the columns of control, RHB, and HSO-mixed RHB was in average 14.8, 8.5, and 3.9 mg m, respectively, during experiment period. Cumulative emissions were reduced by 42.6% and 73.3% using RHB and HSO-mixed RHB columns, respectively. The application of RHBs collected from the column significantly increased dry matter and crude protein production in maize, with notable enhancement by HSO-mixed RHB application. These results demonstrate the integrated effectiveness of RHB application in NH management, in which NH emissions from the pig house are adsorbed using RHB column, and the NH-adsorbed RHB collected from column is recycled through the soil to support plant growth.