Zhou Jun, Zhou Li-Xiang, Wong Woo-Chung
Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Huan Jing Ke Xue. 2013 Jul;34(7):2752-7.
Seven commonly adopted extraction schemes were selected to extract extracellular polymeric substance (EPS) from the sludge, and the dewaterability of sludge was also investigated before and after extracting EPS. Results showed that Formaldehyde + NaOH and 2% EDTA methods were proved to be effective in extracting EPS from the sludge, and the total EPS production of the total suspend solid was 128.86 mg x g(-1) and 42.38 mg x g(-1), respectively. However, the cell destructed seriously after extracted by Formaldehyde + NaOH and 2% EDTA methods. Heating method was a gentle and efficient method, and the total EPS production was 21.97 mg x g(-1). Sludge dewaterability was largely improved after extracted slime, loosely bound EPS and tightly bound EPS from the sludge flocs. It was also found that the higher content of EPS in slime, the worse dewaterability of sludge, and sludge dewaterability would be deteriorated when EPS was released from other layers to slime. Capillary suction time (CST) values of sludge from the ShekWuHui and Stonecutters Island Treatment works were 132.9 s and 229.9 s compared to 80.8 s and 79.4 s, separately after extracted Slime from sludge flocs, and the dewaterability of sludge was greatly improved.
选择了七种常用的提取方案从污泥中提取胞外聚合物（EPS），并研究了提取EPS前后污泥的脱水性能。结果表明，甲醛+氢氧化钠和2%乙二胺四乙酸（EDTA）方法被证明能有效从污泥中提取EPS，总悬浮固体的总EPS产量分别为128.86毫克/克和42.38毫克/克。然而，用甲醛+氢氧化钠和2%EDTA方法提取后细胞严重受损。加热法是一种温和且高效的方法，总EPS产量为21.97毫克/克。从污泥絮体中提取黏液、松散结合的EPS和紧密结合的EPS后，污泥脱水性能得到很大改善。还发现黏液中EPS含量越高，污泥脱水性能越差，当EPS从其他层释放到黏液中时，污泥脱水性能会恶化。与从污泥絮体中提取黏液后分别为80.8秒和79.4秒相比，石鼓环和昂船洲污水处理厂污泥的毛细吸水时间（CST）值分别为132.9秒和229.9秒，污泥脱水性能得到极大改善。
