Desulfurization waste water zero-discharging treatment technology for coal-fired power plants

Abstract

The invention provides a desulfurization waste water zero-discharging treatment technology for coal-fired power plants. The desulfurization waste water zero-discharging treatment technology comprises a pretreatment system, a membrane process distillation system, a fresh water reuse and purification system, a concentrate water recovery and evaporative crystallization system and a sludge treatment system. The pretreatment system comprises the processes of pH adjustment, first-stage precipitation, coagulation and second-stage precipitation. Waste water treated by the pretreatment system enters the membrane process distillation system, and discharged sludge enters a sludge treatment system. One side of a membrane assembly in the membrane process distillation system is the cooling side and is in a negative pressure state. The waste water evaporates on the membrane surface and passes through the cooling side of the membrane surface in the form of vapor, and then the vapor coagulates into fresh water and enters the fresh water reuse and purification system, so that fresh water is reused by power plants and other relevant water-consuming systems. The other side of the membrane assembly is the heating side, and waste water not passing through the membrane surface forms concentrate water and enters the concentrate water recovery and evaporative crystallization system, so that resource utilization of concentrate water is achieved. Thus, desulfurization waste water zero discharging is realized.

Description

technical field [0001] The invention relates to a zero-discharge treatment process for desulfurization wastewater in a coal-fired power plant. Background technique [0002] my country is a country that mainly burns coal. At present, more than 62% of the cities in the country are SO 2 The concentration exceeds the second-level standard of national environmental quality, and the area accounting for about 40% of the country's area is affected by SO 2 Acid rain pollution caused by massive discharge, so control of SO 2 pollution is inevitable. Flue gas desulfurization is currently the only desulfurization method for large-scale commercial application in the world. 2 The main technical means of pollution. SO 2 The concentration is low, and the technical difficulty is relatively high [11]. [0003] Among all the desulfurization technologies, the wet flue gas desulfurization technology is mature, with high desulfurization efficiency, good adaptability to coal types, and reliab...

AI Technical Summary

Problems solved by technology

[0013] 3. The current conventional treatment process

[0019] In recent years, large international water treatment companies (such as GE, Veolia, McWong, Arquette, etc.) have proposed their own "zero discharge" process for zero discharge of power plant wastewater, and the main process is pretreatment-evaporation-crystallization process; At present, the vast majority of power plants only achieve partial wastewater discharge reduction, or only realize the reuse of some types of wastewater after treatment, while other wastewater such as circulating cooling system sewage, desulfurization wastewater, non-recurring wastewater, etc. are directly discharged or partially discharged after treatment. Used for humidification of dry ash, without truly realizing zero discharge of waste water

Images