night soil
5.Abstract: The generation and control of odorous gases in treating night soil sludge was exploited in this paper.The results indicated that high concentration odorous gases can be generated during whole process in treating night soil sludge.In order to control the secondary pollution of odorous gases,the authors put forward a new kind of deodorization process-combustion in methane boiler and absorbde in washer.
7.Moreover, by 2004, all the husbandry industry in the area of protection zones of drinking water sources and within the Fifth Ring Road will be closed down or moved out. By 2007, all the wastewater from the allowed large scale husbandry industry will should comply with discharge limits after necessary treatment and night soil utilization rate shall reach 90%.
9.The major way of lossing heat at night is through around structure which accounts for 76% of all lossing heat. The second way is crosswise lossing heat by soil which accounts for 12.5%～13.2% of all lossing heat. The final way is chink lossing heat which accounts for 5.6%～10.7% of all lossing heat. Therefore, covering grassy marshland at night and digging cold preventive ditch are major ways of heat preservation.
