pH值对污泥发酵产酸的影响

利用剩余污泥厌氧发酵产生挥发性脂肪酸,可作为污水脱氮除磷的有机碳源,而pH值是发酵产酸过程中重要的控制参数.研究了不同pH值条件下剩余污泥厌氧发酵产酸过程中各参数变化规律,探索pH值对其过程的影响及其分析.结果表明,碱性条件有利于污泥发酵产酸过程,实验最佳条件是控制反应初始pH值为10.0,仅8d发酵挥发性脂肪酸浓度就达到8.90 mmol/L.此外,污泥在发酵过程中,酸性条件下NH4+-N和PO43--P的释放量均大于碱性条件.

Influence of pH values on fermentation and acidogenesis of waste activated sludge

The volatile fatty acids (VFAs), which are made from the waste activated sludge, are usually regarded as the useful carbon sources for the process of denitrification and dephosphorization in sewage plants. The pH value is an important parameter to affect the anaerobic fermentation. In the study, the change law of many parameters with different pH values during the anaerobic fermentation and acidogenesis of a waste activated sludge was revealed. The results show that alkaline condition is beneficial to the process of fermentation and acidogenesis and the optimal condition is the initial pH value of 10.0 in the process. Under the condition, the VFAs concentration reached 8.90 mmol/L in the eighth day of the process. Furthermore, the release amounts of NH₄⁺-N and PO₄^3--P of the sludge in acid conditions are larger than that under alkaline conditions.