活性污泥中温与高温絮凝特性

为了揭示中温与高温活性污泥的絮凝特性及其作用机制，本研究采用序批式反应器，分别在35℃及55℃条件下培养了中温与高温活性污泥，考查了2种活性污泥的相互作用能与胞外聚合物的特性。研究结果表明：高温污泥系统出水浊度为（145±22．9）NTU，是中温污泥系统的近50倍。中温污泥的相互作用能曲线存在明显的势垒（313．4×10^-20J），而高温污泥不存在明显势垒；高温污泥的松散型胞外聚合物与紧致型胞外聚合物的含量分别为中温污泥的12倍及3．5倍，且胞外聚合物中蛋白质、多糖、腐殖酸和DNA的含量均高于中温污泥的含量。这表明，尽管高温污泥相互作用能势垒低，但其胞外聚合物，尤其是松散型胞外聚合物含量过高，是高温污泥絮凝性能低的内在机制，而胞外聚合物组成特征不是中温和高温污泥絮凝性能差异的主要原因。

Bioflocculation of mesophilic and thermophilic activated sludge

Two sequencing batch reactors with temperatures of 35℃ and 55℃ were employed to investigate the bioflocculation characteristics and mechanisms of mesophilic and thermophilic activated sludges by testing their interaction energies and extracellular polymeric substances quantities. The results show that thermophilic sludge system had an effluent turbidity of （145 ± 22.9）NTU, which is almost 50 times higher than mesophilic sludge system. An obvious barrier （313.4 × 10^-20j） existed in the interaction energy curve of mesophilic sludge, while that of thermophilic sludge didn＇t. Thermophilic sludge had higher quantities of both loosely and tightly bound extracellular polymeric substances, which was 12 and 3.5 times higher than that of mesophilic sludge re- spectively. And the components of thermophilic sludge extracellular polymeric substances （proteins, polysaccha- rides, humic acids and DNA） were also higher than mesophilic sludge. This indicates that although thermophilic sludge has lower interaction energy barrier, its higher concentration of extracellular polymeric substances, especial- ly loosely bound extracellular polymeric substances is the internal cause for its poor flocculation ability. Different compositions of extracellular polymeric substances are not the main cause for their flocculation discrepancy.