在化学肥料发明和使用以前,城乡人粪尿是亚洲,尤其是中国种植业养分的重要来源,化学肥料在替代人畜粪尿的同时,也产生了日益严重的大气、水体污染问题。为减轻污染,发达国家采用电加温烘干的方法处理城市粪便。这种处理方法不仅投资大、成本高,产生的污水 Before the invention and use of chemical fertilizers, human waste in urban and rural areas was an important source of nutrients for farming in Asia, especially in China. As chemical fertilizers replaced human and animal manure, they also created increasingly serious air and water pollution problems. In order to reduce pollution, developed countries use electric heating drying method to deal with urban manure. This approach not only invest large, high cost, resulting in sewage