ABSTRACT
Objective To perform a hygienic assessment of the three-chamber septic tanks and analyze the efficiency of non- hazardous treatment of feces and the impact on the environment, so as to provide the reference for the three-chamber septic tanks improvement test. Methods From September 2007 to January 2008, the 20 latrines of residents and the three-chamber septic tanks were selected by simple random sampling method from A village of A town , Chongqing , as the investigation point,with suitable economic conditions,the status of the latrines with three-chamber septic tanks were surveyed, and the hygienic and environmental indicators of the third chamber feces samples were detected. Results After the implementation of the three-chamber septic tanks, the rural ecological environment was improved. The samples test showed that pH value was basically in the range of 8-9, the qualified rate was 85%, as for the other indicators, the qualified rates were generally lower. The qualified rate of chemical oxygen demand, ammonia nitrogen and total nitrogen was only 5% , five-day biochemical oxygen demand and total phosphorus was 10% , SS and the color was 15% , fecal coliform value of the samples were not qualified. Conclusion The management of the three-chamber septic tanks needs to be improved. If the liquid dung of septic tanks was directly discharged, it will cause secondary environmental pollution.So it should be deeply treated.