Abstract
Anaerobic processes have been successfully applied in the treatment of municipal and industrial wastewaters. Judicious use of
nutrients in anaerobic treatment has not been systematically investigated. The optimal nutrient dosage for anaerobic wastewater
treatment systems is largely unknown. In this paper, COD:N:P ratio used by various researchers in anaerobic wastewater
treatment systems for treating different types of wastewaters are compiled and critically analyzed. In order to have uniformity,
concentrations of carbon, nitrogen and phosphorus have been converted into equivalent terms as COD:N:P and ranges for this
ratio for all the constituents of nitrogen and phosphorus with respect to carbon (COD) are given. Phenol COD represents a
substrate which is difficult to degrade. Phenol can be found in various effluents resulted from industrial activities, such as:
pharmaceuticals, pesticide, dye manufacturing, synthetic chemicals, coal gasification, coke production, fertilizer, and pulp and
paper. The author has attempted for treatment of phenolic wastewater a representative of the industrial wastes which lacks
nutrients and requires addition of nutrients such as nitrogen and phosphorus. The optimum COD: N: P ratio of 300:1:0.1 for
phenolic wastewater has been reported. It is hoped that the information presented in this study would facilitate in maintaining the
COD: N: P ratio in anaerobic processes.