剩余污泥热水溶性有机物的提取方法优化研究

热水溶性有机物含量和组成是表征剩余污泥(简称为污泥)中有机质生物可利用性的重要手段.分析了不同热水淬时间(1~24h)和不同ρ(污泥)(0.7~36.0g/L)对热水溶性蛋白质和碳水化合物等溶出的影响,据此对剩余污泥中热水溶性有机物的提取方法进行了优化. 结果表明:污泥在60℃水淬8h时,水溶性蛋白质和碳水化合物的溶出率达到最大,分别为34.6%和36.1%；但是,随着水淬时间的延长,部分蛋白质被转化成氨氮,部分碳水化合物也发生了转化和降解,致使二者的浓度降低. 考虑测试分析的时间效率和溶出率稳定性,污泥热水溶性有机物最优水淬时间建议设置为5h. 研究结果表明,热水溶性有机物的溶出率随ρ(污泥)降低呈升高趋势,当ρ(污泥)为0.7g/L时,热水淬5h后蛋白质和碳水化合物的溶出率最大,二者分别为52.9%和36.6%. 

Optimization for Extraction of Hot Water-Soluble Organic Matter from Waste Activated Sludge

The content and composition of hot water-soluble organic matters are important parameters for characterizing the bioavailability of organic matters in sludge. The pattern of hot water-soluble organic matters released from the waste activated sludge was investigated, and the effects of different water quenching time (1-24h) and sludge concentration (0.7-36.0g/L) on the release of proteins and carbohydrates were simultaneously evaluated. The released amounts of protein and carbohydrate reached their maximum values of 34.6% and 36.1% respectively, when the waste activated sludge was treated by water quenching at 60oC for 8hours. However, with the further increase of the water quenching time, proteins were reduced into ammonia nitrogen, and the degradation of carbohydrate started as well. This led to reduction of the water-soluble protein and carbohydrate concentration. Considering the time efficiency of the test analysis and dissolution rate stability, the optimal water quenching time of the hot water-soluble organic matter was recommended to be set to 5h. When treated with different sludge concentrations, lower initial sludge concentrations led to higher dissolution rate of hot water-soluble organic matters. When the initial sludge concentration was 0.7g/L and water quenching for 5h at 60oC, the percentages of protein and carbohydrate released arrived at 52.9% and 36.6% respectively, which was the maximum value from 0.7-36.0g/L.