预处理及添加牛粪提高废水污泥厌氧发酵效率

Improvement of anaerobic fermentation efficiency of wastewater sludge in a nucleotide plant by pretreatment and adding cow dung

核苷酸厂废水污泥具有丰富的多糖和蛋白质,研究其综合利用具有重要意义。实验采用多种物理和化学预处理方法,发现热-碱耦合预处理效果最佳。污泥发酵采用两段控温法,初始pH=4.5,前96 h控温55℃水解酸化,之后控温35℃甲烷发酵,并研究了添加外源牛粪菌群对废水污泥消化的影响。预处理后添加牛粪厌氧发酵,最大SCOD达到6 300 mg/L,最终240 h时产气率达到276 mL/g,TS去除率达到36%,为后续深入研究和实现污泥的资源化利用及污泥减量化提供了基础。

The wastewater sludge in a nucleotide plant is rich in polysaccharide and protein. Therefore,studying its comprehensive utilization is of important significance. A variety of physical and chemical pretreatment methods have been conducted for the experiments. It is found that heat-alkali coupled pretreatment process has the best efficiency. The two-step temperature controlling method is used for sludge fermentation. Its initial pH is 4.5. In the first 96 h , the temperature should be controlled at 55℃for hydrolysis acidification. Then,the temperature should be controlled at 35℃for methane fermentation. The effects of adding external cow dung bacteria on the digestion of wastewater sludge are studied. After the pretreatment,cow dung bacteria are added for anaerobic fermentation. The maximum SCOD reaches 6 300 mg/L. It is observed that at the final time of 240 h ,the gas production rate reaches 276 mL/g , and TS removing rate 36%. The process provides bases for the subsequent and advanced research , realization of re-source utilization,and sludge decrement.