반류수 처리를 위한 생물막 아질산화공정에서 유기물과 고형물 농도에 따른 온도 영향 평가

Abstract

An experimental study of biofilm nitritation system for high-strength ammonium wastewater has been carried out to examine the temperature effect on different organic and solid concentration. Operating temperature varied from 35°C to 15°C. The influent N concentration of identical three reactors was adjusted to about 300 mg NH_4-N/L. A control unit fed with a synthetic wastewater, while the others were fed with reject water which is consisted of the supernatant of both digester and thickener. The results indicated that nitrite accumulation was stable in temperature range of 35°C to 25°C. However, nitritation was significantly reduced at below 20°C. Free ammonia (FA) and free nitrous acid (FNA) were major inhibitors to the nitrite oxidizer for nitrite accumulation in lower temperature. From the estimation of temperature coefficient (θ) of biofilm and suspended nitritation system, biofilm nitritation system could absorb the negative temperature effect compared with suspended nitritation system.