Study on the Ozone Treatment of Night-Soil Sewage

Night-soil pollution is a serious environmental and public health problem in highly populated and developing countries. Static and dynamic experiments were carried out to study the chroma and COD removal effect of night-soil sewage by ozone oxidation technique. The results show that, both the chroma and COD of night-soil sewage decrease with the growth of ozone dosage, and the chroma removal rate can be up to 90%, while the COD removal rate is less than 50%. The utilization efficiency of ozone decreases with the chroma reduction or the reactor diameter increasing. The appropriate diameter of ozonization reactor used in eco-friendly toilets is 150mm, and the optimal ozone dosage is 400mg/L.