DME-共溶剂体系对污泥脱水效果的影响及机理研究

Study on the Effect and Mechanism of DME-Co-solvent System on Sludge Dewatering

利用DME进行污泥脱水作为一种崭新的污泥深度脱水技术具有极大的潜力。针对这一技术应用过程中尚存在DME用量过大的问题,探讨了加入不同共溶剂对DME用于污泥脱水的影响,并实测了不同反应时间、DME添加量下含水率、脱水率、结合水变化和各种有机质的变化情况。结果表明:4种共溶剂对脱水的促进效果为:乙醇>甲醇>丙酮>氯化钠,乙醇对DME脱水的促进作用最明显。在保持相同脱水率的情况下,加入DME质量0.8%~2.4%的乙醇助剂,可以减少质量比0.45~3.7倍的DME使用量。加入助剂后DME对污泥中糖类的提取率大幅上升,表明助剂促进脱水的关键在于通过改变溶剂体系的极性水平使其更加靶向提取糖类物质,增强对糖类的溶解能力和选择性,破坏其与水的结合结构,从而有效地带出或者释放出更多的水。

The use of DME for sludge dewatering has great potential as a new deep dewatering technology of sludge.In view of the problem of excessive amount of DME in the application of this technology,this study explored the influence of adding different co-solvents on DME used for sludge dewatering,and measured the water content and dehydration rate under different reaction times and DME addition levels.Combining water changes and changes in various organic matter.The results showed that the promoting effect of the four co-solvents on dehydration was as follows:ethanol>methanol>acetone>sodium chloride.Ethanol has the most obvious promoting effect on the DME dehydration.In the case of maintaining the same dehydration rate,adding ethanol additive with a mass of 0.8%~2.4%DME can reduce the DME usage by 0.45~3.7 times.After adding additives,the extraction rate of DME for carbohydrate in the sludge increased significantly,indicating that the key to the additives to promote dehydration is to change the polarity level of the solvent system to make it more targeted to extract carbohydrate and enhance the ability to dissolve carbohydrate and selectivity,destroying its binding structure with water,thereby effectively bringing out or releasing more water.