A pilot field-scale study on biotrickling filter treatment of NH3-containing odorous gases from organic waste composting plants

Abstract

The use of a biotrickling filter was investigated for a pilot field-scale elimination of NH 3 gas and other odorous gases from a composting plant in Tongzhou District, Beijing. The inlet gas flow rate was 3500 m 3 /h and NH 3 concentration fluctuated between 2.76–27.84 mg/m 3 , while the average outlet concentration was 1.06 mg/m 3 with an average of 94.9% removal. Critical volumetric loading (removal efficiency=100%) was 11.22 g-N/(m 3 ·h). The odor concentration removal was 86.7%. NH 3 removal efficiency decreased as the free ammonia (FA) in the trickling liquid increased. The pressure drop was maintained at about 50 Pa/m and was never more than 55 Pa/m. During the experiment, there was neither backflushing required nor any indication of clogging. Overall, the biotrickling filter was highly efficient and cost-effective for the simultaneous biodegradation of NH 3 and other odorous gases from composting, suggesting the possibility of treating odorous gases at the industrial level.