Nitrogen-retaining property of compost in an aerobic thermophilic composting reactor for the sanitary disposal of human feces  

作　　者：Fan BAI Xiaochang WANG 

机构地区：[1]Key Lab of Northwest Water Resource,Environment and Ecology,Ministry of Education of China,Xi’an University of Architecture and Technology,Xi’an 710055,China [2]Department of Geo-science and Environmental Engineering,Baoji University of Arts&Sciences,Baoji 721007,China

出　　处：《Frontiers of Environmental Science & Engineering》2010年第2期228-234,共7页环境科学与工程前沿（英文）

基　　金：the National Natural Science Foundation of China(Grant No.51021140002);the National Program of Water Pollution Control(No.2008ZX07317-004);the Program for Changjiang Scholars and Innovative Research Team in University(No.IRT0853)。

摘　　要：Aerobic composting is a method for the sanitary disposal of human feces as is used in bio-toilet systems.As the products of composting can be utilized as a fertilizer,it would be beneficial if the composting conditions could be more precisely controlled for the retention of fecal nitrogen as long as possible in the compost.In this study,batch experiments were conducted using a closed aerobic thermophilic composting reactor with sawdust as the bulk matrix to simulate the condition of a bio-toilet for the sanitary disposal of human feces.Attention was paid to the characteristics of nitrogen transformation.Under the controlled conditions of temperature at 60°C,moisture content at 60%,and a continuous air supply,more than 70%fecal organic removal was obtained,while merely 17%fecal nitrogen loss was observed over a two-week composting period.The nitrogen loss was found to occur mainly in the first 24 h with the rapid depletion of inorganic nitrogen but with an almost unchanged organic nitrogen content.The fecal NH4-N which was the main component of the inorganic nitrogen(>90%)decreased rapidly in the first day,decreased at a slower rate over the following days,and finally disappeared entirely.The depletion of NH4-N was accompanied by the accumulation of NH3 gas in the ammonia absorber connected to the reactor.A mass balance between the exhausted NH3 gas and the fecal NH4-N content in the first 24 hours indicated that the conversion of ammonium into gaseous ammonia was the main reason for nitrogen loss.Thermophilic composting could be considered as a way to keep a high organic nitrogen content in the compost for better utilization as a fertilizer.

关 键 词：nitrogen retention composting reactor human feces AEROBIC THERMOPHILIC FERTILIZER 

分 类 号：X38[环境科学与工程—环境工程]