脱硫废水污泥脱水方式的比较研究

污泥脱水是电厂脱硫废水处理达标排放的最后环节,设计不合理或运行不当会影响整个脱硫废水处理系统的最终运行。常见的脱硫废水污泥脱水装置有板框式压滤机和离心式脱水机2种,某电厂脱硫废水处理系统污泥原采用离心脱水机脱水,所得泥饼含水率大于80%,呈半流体状,装卸运输中造成二次污染。为此,对脱水系统进行改造,将原有的离心脱水机更换为板框式压滤机,同时增加了污泥缓冲罐、污泥循环泵和污泥给料泵等。对改造前后脱水机的运行状况进行了全面比较研究,结果表明,板框压滤机更适合该电厂脱硫废水污泥脱水工艺,所得泥饼固体质量分数达30%以上,且系统运行稳定,能耗低。

Comparative Study on Desulfurization Wastewater Sludge Dewatering

As the final stage of the FGD wastewater treatment and discharge process in the power plant, sludge dewatering may affect the whole wastewater processing system operation if it is not designed reasonably or operated properly. There are two kinds of sludge dewatering devices, the frame filter press machine and the centrifugal dewatering machine. In a power plant, the centrifugal dewatering machine is originally adopted in the desulfurization wastewater sludge treatment and the produced cake contains more than 80% of water and presents semi-fluid state, causing secondary pollution in the process of loading/unloading and transportation. Therefore, the dewatering system is modified by replacing the original dewatering centrifuge with the frame filter and installing the sludge buffer tank, sludge circulation pump and sludge feed pump. The comparative study on the dewatering devices before and after the modification is conducted. The study results show that the frame filter is more suitable for the desulfurization wastewater sludge treatment process. The mass fraction of the dewatered cake solid is higher than 30%, and the operation of the system is stable with lower energy consumption.