采用树脂法从剩余污泥中提取微生物絮凝剂

摘要

Microbial flocculant (MBF) extraction from excess sludge of municipal wastewater treatment plant by the cation exchange resin (CER) method was systematically investigated. The results show that MBF extracted from neutral or alkalescent sludge has higher flocculating activity than that from acid sludge. Increasing sludge concentration is beneficial to the MBF extraction. The flocculating activity of the extracted MBF can be enhanced by increasing the stirring intensity or the added CER dose. However, with the extending of extraction time, the flocculating activity of the extracted MBF increases and reaches a peak, and then decreases. Through the orthogonal experiment project, the optimal process conditions of MBF extraction from excess sludge by the CER method is obtained as follows. Sludge mass concentration is 9 g/L, stirring velocity is 650 r/min, resin dose is 60 g/g, and the extracting time is 3 h. Under this condition, the flocculating activity of the extracted MBF can be improved to about 50%. Therefore, the CER method is feasible to extract MBF from excess sludge, which can save the cost of MBF production, as well as realize the resource reuse of excess sludge.%采用阳离子交换树脂(CER)法从剩余污泥中提取微生物絮凝剂(MBF),对各种影响因素进行系统研究.研究结果表明:污泥pH对MBF的提取和絮凝效果影响较大,在中性或偏碱性条件下提取的MBF表现出较高的絮凝率；污泥质量浓度越高,所提取的絮凝率物质越多；随着搅拌强度和树脂投加量的增大,CER法所提取MBF的絮凝率呈现增大的趋势；随着提取时间的延长,所得MBF的絮凝率呈现先增大后降低的趋势.通过正交实验获得树脂法从剩余污泥中提取MBF的优化工艺条件如下:污泥质量浓度为9g/L,搅拌速度为650 r/min,树脂投加量为60 g/g VSS,提取时间为3h,所提取MBF对高岭土悬浊液的絮凝率接近50％.树脂法可用于从剩余污泥中直接提取MBF,在降低MBF生产成本的同时实现污泥的资源化利用.