污泥碱性厌氧发酵可生产挥发性脂肪酸(VFAs),然而碱性发酵后的污泥脱水性能差,影响了发酵液的后续利用。采用生物淋滤法处理发酵污泥,研究了生物淋滤过程中发酵污泥脱水性能的变化,并分析了脱水性能得到改善的原因。结果表明,经过72h调理后污泥比阻降低至5.39×10^11m/kg,泥饼含水率达到75.17%,污泥从难脱水变为易脱水。经生物淋滤调理24h后,蛋白质、多糖含量分别下降到0.49和5.54mg/gVSS,降低了90.3%和28.0%,说明污泥胞外聚合物的减少有利于提高污泥的脱水性能。调理过程中VFAs无明显损失,VFAs回收率可从调理前的7.62%提高到调理后的95.95%。
Volatile fatty acids (VFAs) can be produced in alkaline anaerobic fermentation of sew- age sludge. However, the dewaterability of the fermented sludge is poor, which exerts a negative effect on the subsequent reuse of the fermented liquid. Bioleaching was applied to improve the dewaterability of fermented sludge. The change in the dewaterability of fermented sludge during the bioleaehing was stud- ied, and the reasons of the improvement were analyzed. The results showed that after conditioning for 72 h, the specific resistance of the bioleached sludge declined to 5.39 × 10^11 m/kg and the moisture con- tent of the sludge cake reached to 75.17% , suggesting that the dewatering of the fermented sludge was transformed from difficult into easy. After conditioning for 24 h, the protein and polysaccharide were 0.49 mg/gVSS and 5.54 mg/gVSS, which decreased by 90.3% and 28.0% , respectively, indicating that the reduction of EPS was favor for improving the sludge dewaterability. After the conditioning, there was no significant loss of VFAs, and the VFAs recovery could be increased from 7.62% to 95.95%.