This paper presents an experimentally verified theory for the mathematical and biochemical progression of aerobic degradation of dissolved organic matter. The stoichiometric model of biochemical oxidation of organic matter is proved by three reactions: 1) the combination of the synthesis of microbial cells directly and oxidative conversion into another carbohydrate, 2) the synthesis of microbial cells from the carbohydrate, and 3) the oxidation of microbial cells through endogenous respiration. On the basis of the three chemical reactions, the progress of BOD is mathematically represented as the sum of three first order kinetics. Kinetics parameter is deter-mined by the modification of Lee's graphical method.
Excluding the affects of nitrification, the curve obtained from the sum of three first order kinetics agrees well with the observed data. The agreement between the theoretical oxygen demand calculated from chemical equation and experimental ultimate oxygen demand obtained from kinetic analysis of data is excellent for reactions in the microbial growth phase (the reaction of 1 and 2 noted above). And the experimental data on bio-oxidation solids production corresponds very nearly to the theoretical value obtained from chemical equation.
