Abstract

Waste materials are increasingly produced by different populations and societies and consequently have great impacts on the environment. Municipal waste waters with their various pollutants and high volumes have intensive and extensive effects on environment as well. Nutrient matters (N&P) have important role on the aquatic ecosystems and their balance. Where as in biological processes various agents are effective on efficiency of process, in this study the effects of C/N and COD/P ratios on the efficiency of nutrient matters (P&N) removal was determined by sequencing batch reactors with activated sludge process. An analytical-descriptive and cross-sectional study was performed on a unit sequencing batch reactor with 18 liter useful volume, feded with waste water in a waste water treatment plant in Tehran. The reason for choosing a municipal wastewater is that the results of the study is applicable to different cities with partial changes. The result showed that with increase of C/N ratio from 8.5 to 14.5, residual nitrate in effluent decreased from 12.3 mg/l to 4.3 mg/l and with increase of COD/P ratio from 31.4 to 46.99, the efficiency of phosphorous removal increased from 56 to 71. It indicates that sequencing batch reactor operating with high load of organic matters is highly capable to remove nutrient matters. Also the effect of temperature on efficiency of Phosphorus removal showed that, minimum of phosphorus removal was been take placed in 10 oC. Furthemore we showed that this efficiency in uppel from 10OC and lower than this temperature has not significant difference.