Emission of gaseous ammonia in aerobic thermophilic composting of human feces

摘要

There is a nitron loss that gaseous ammonia was exhaused from aerobic composting of human feces, which was important how emission of gaseous ammonia was in composting. Batch experiments were conducted using a closed aerobic composting reactor with sawdust as the bulky matrix to simulate the condition of a bio-toilet for sanitary disposal of human feces. Attention was paid to the characteristics of emission of gaseous ammonia under the thermophilic condition. The results indicated that: merely 17% fecal nitrogen loss(inorganic nitrogen Nino, mainly NH4+-N) observed in a two-week composting period during aerobic thermophilic composting at 60°C. Concentration and rate of ammonia increased quickly firstly and reached maxium, then decreased and reached zero almostly finally, and accumulation of ammonia increased quickly firstly, then increased gradually to an constant amount finally(firstly 1 day) at 60°C. This show that: Emession of ammonia was important way to nitrogen loss at initial stage of compost. Ammonification of Norg may have been hindered and emmission of NH4+-N accelarated under the thermophilic condition. As a result, nitrogen loss was controled at initial stage of compost and thermophilic composting can be considered as a method to improve the nitrogen retaining property of the compost.