活性污泥胞外聚合物提取方法比较与热碱法优化

为比较不同方法对曝气池活性污泥胞外聚合物（EPS）的提取效果，采用6种方法对EPS进行提取。结果表明：热碱法对EPS的提取量最大，提取总量为64.95 mg·g-1；其次是NaOH法、CER法和加热法，超声法和硫酸法对EPS的提取效果不佳，提取量低于10 mg·g-1；在所提取的EPS中，多糖含量高于蛋白质。为研究pH、水浴温度和时间对热碱法提取效果的影响，采用正交实验对热碱法的提取条件进行优化，确定热碱法提取EPS的适宜条件为水浴温度80℃，加热时间10 min，pH 13，该条件下蛋白质和多糖的提取量达到最大，分别为29.55 mg·g-1和33.37 mg·g-1。

Extraction of extracellular polymeric substances from activated sludge and optimization of thermal-alkaline method

The extraction methods of six different extracellular polymeric substances (EPS) were studied on activated sludge sampled from an aeration tank. Results showed that the thermal-alkaline method gave the highest extraction values (64.95 mg·g-1), followed by sodium hydroxide, a cation exchange resin, and the thermal method, while ultrasonication and the sulfuric acid method resulted in relatively low extraction values (below 10 mg·g-1). In addition, the extracted EPS contained more carbohydrates than proteins. To optimize the extraction conditions of the thermal-alkaline method, the effect of pH, water bath temperature, and water bath time on the extraction were investigated through an orthogonal experiment. The optimum conditions were determined, as follows:pH of 13, water bath temperature of 80℃, and water bath time of 10 min. The highest extraction values in terms of proteins (29.55 mg·g-1) and carbohydrates (33.37 mg·g-1) were achieved under the optimum conditions.