Zero-discharge technique for separating sludge and salt from desulfurization wastewater

• Main Authors: Lu, Xin, Li, Wulin, Yan, Feng, Zeng, Zhenguo, Li, Kuan, Ji, Xianhua, Zhang, Xiong, Xu, Hui, Wang, Chen, Liu, Qinqin
• Format: Patent
• Language: English
• Published: 28.04.2020
• Subjects: CHEMISTRY; METALLURGY; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; TRANSPORTING; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

A zero discharge process for separating sludge and salt from desulfurization wastewater includes a pretreatment process, a membrane treatment process and an evaporative crystallization process; in the pretreatment process, the desulfurization wastewater enters a raw water tank, an aeration fan introduces compressed air into the raw water tank, and the wastewater is lifted to first-stage reaction and clarification by a raw water pump; in the membrane treatment process, the incoming wastewater is first filtered by ultrafiltration, then enters a pH adjustment tank, and is pumped into a nanofiltration membrane separation system and a reverse osmosis membrane separation system; in the evaporative crystallization process, the incoming wastewater is first subjected to two-stage preheating, then enters a degasser, and finally enters an evaporative concentration system and a crystallization system.