Choose of solid organic carbon sources for biological denitrification in surface water

Organic matter release and nitrate biological degradation test were conducted in order to find more ecnomical and efficient carbon source,with hust, wheat straw, rice straw and mixed carbon sources as the main research object. COD determination indicated that all carbon sources had different COD releasing ability and the release ammont of hust, wheat, rice straw were 1.12 mg/g·d, 1.03 mg/g·d and 1.89 mg/g·d, the period of which were all more than 20 days. Wheat straw and hust had better denitrifying effect and the nitrogen removal rate reached 72% and 57% after 10 days of biological denitrification. The average denitrification rate in order were hust>;wheat straw>;rice straw>;mixed carbon sources. Hust was the appropriate solid organic carbon source for purification of urban minor-polluted water.