Studies on the Treatment of Night Soil. X. Treatment Effects of Digested Night Soil by Activated Sludge

Abstract

Digested night soil was treated with activated sludge and changes in the components were examined. In the actual plant, the BOD values decreased by the treatment, but the COD, protein, and carbohydrate contents did not. In the batch examination, oxygen uptake decreased but TOD and TOC values scarcely decreased, and COD values rather increased by the examination. From this evidence, it was assumed that the increase of COD values will be due to the presence of non-biodegraded substances and to the increase of the carbohydrate and non-carbon substances, especialy NO₂-nitrogen and self-digested substances of the sludge.