Bulking Controls Induced by Nitrogen Insufficiency in Yeast System
酵母菌处理系统中氮缺乏引起的污泥膨胀控制

The effect of nitrogen addition to salad oil manufacturing wastewater system was studied. The results of batch experiments demonstrated: 1. addition of nitrogen was helpful to improve oil removal, and the oil removal rate was above 90% when COD/N value was between 50/1 and 20/1; 2. addition of nitrogen improved the sludge settleability, which was much better under COD/N value of 50/1 and 20/1. In the continuous experiment, the value of slude volume index(SVI) was between 100 and 200, and the removal rates of oil and COD were above 95% and 90%, respectively when the COD/N ratio was kept at value of 20/1. Nitrogen addition to salad oil manufacturing wastewater system is an effective method for preventing or controlling sludge bulking.