Abstract
Decomposition of the human waste was investigated by the method used for the quantitative understanding of the humus degree. COD, BOD, and absorbance of the human waste were measured for 22-30 days.
COD and BOD were reduced with the increase in the elapsed time. It was made clear that the organic matters which had absorbance at 600-1000 nm were decomposed to those absorbing at 370-550 nm from the change of log absorbance.
Difference between log absorbance at 400 nm and at 600 nm (SLOD) was related to COD measured for 20 days by following equation, dlog COD/dlog SLOD=-2.7. The relationship between SLOD and BOD was dlog BOD/dlog SLOD = -4.2.
SLOD is able to determine quantitatively the decomposition rate of the human waste, instead of COD or BOD, because concentration of the waste have no effects on the values of SLOD.
