Studies on the Treatment of Night Soil. (2)

Abstract

The mechanism of removal of night soil components by treatment plant is reviewed. For night soil, two aerobic treatment systems are mainly used ; the one is a direct treatment of raw night soil by aerobic digestion and the other is a treatment with activated sludge after anerobic digestion of night soil. The mechanisms for removal of substances responsible for BOD (biochemical oxygen demand) and COD (chemical oxygen demand), and of nitrogen compounds by these two methods are described. Identification of substances remaining in the effluent from both treatment methods, and of the chloroform-forming substances on chlorination are reviewed.