厌氧消化污泥脱水性能变化的试验与分析

研究了剩余污泥在中温厌氧消化条件下脱水性能的变化及其作用机制。剩余污泥厌氧消化过程中,消化污泥的比阻(SRF)相比于剩余污泥有一定的减小,消化污泥的过滤速度有一定的改善,但改善不明显。聚丙烯酰胺(PAM)、FeCl3和聚合氯化铝(PAC)3种絮凝剂调理试验显示,消化污泥的最佳投药量相对于剩余污泥均有所增加,说明消化污泥脱水性能变差。分析了2种污泥中胞外聚合物(EPS)含量及污泥颗粒特性的变化,表明消化过程导致EPS的降解并向液体中释放。随着EPS含量的减少,由EPS架桥形成的较大絮体解体成为较小的污泥颗粒,污泥中小颗粒的比例增加,污泥的脱水性能变差。

The Experiment & Analysis of Dewatering Performance Change of Anaerobic Digested Sludge

The dewatering performance change and function mechanism of excess sludge are studied under the condition of mesophilic anaerobic digestion.During the period of excess sludge anaerobic digestion,SRF value of digested sludge will be a little smaller than that of excess sludge and the filtration rate of digested sludge will be improved a little not very apparently.The conditioning experiment using PAM,FeCl3 and PAC can reveal that the optimal dosages of digested sludge are all increased compared to excess sludge and dewatering performance of digested sludge will become worse.Through analyzing extra-cellular polymeric substances(EPS) content and the characteristics of sludge particle,it is found that digestion process can lead to the degradation of EPS and release into liquid.With the decrease of EPS content in sludge,the larger floc,which is formed by the bridging of EPS,will be disintegrated into smaller particles.The proportion of smaller particles in sludge will be increased and dewatering performance of digested sludge will become worse.