Process and system for treating electric power plant waste water

Abstract

The invention relates to a method for treating waste water from a power plant and a system for realizing the same. The system comprises a pre-treatment system and an evaporative crystallizing system which are connected with each other; the pre-treatment system is connected to the waste water from the power plant, the majority of SS, heavy metals, Mg<2+>, F<-> and sulfate radicals in the waste water from the power plant are removed by coagulating sedimentation, and organic pollutants and ammonia nitrogen are also removed; the CaSO4 content in the waste water is adjusted to be far less than saturated concentration of the CaSO4, and the pH value is adjusted back to make partial CO3<2-> converted into HCO3<->; and the waste water treated by the pre-treatment system flows in the evaporative crystallizing system, by evaporation concentration, the dissolved solids in the waste water reach and exceed the saturated concentration to form salt crystal, and the solid-liquid separation is performed. The method has the advantages of effectively removing suspended matters, organic matters, fluorine and heavy metals in the waste water from the power plant, removing dissolved salt such as Ca<2+>, Mg<2+>, Cl<->, SO4<2-> and the like which can not be removed by the prior method for treating the waste water from the power plant, and basically meeting zero emission, and the treated waste water can be reutilized.

Description

technical field [0001] The invention relates to a process method for treating sewage and wastewater, and also relates to a system for realizing the process method, more specifically, to a method and system for treating desulfurization wastewater or wastewater containing salt in a power plant. Background technique [0002] The waste water generated in the process of flue gas wet desulfurization (limestone / gypsum method) in coal-fired power plants comes from the waste water discharged from the desulfurization absorption tower. In order to maintain the balance of substances in the slurry circulation system of the desulfurization unit, prevent the soluble part of the flue gas, that is, the chlorine concentration from exceeding the specified value, and ensure the quality of gypsum, a certain amount of wastewater must be discharged from the system. The wastewater mainly comes from the gypsum dewatering wastewater and cleaning system. The impurities contained in wastewater mainly i...

AI Technical Summary

Problems solved by technology

[0014] Through the above treatment system, the content of suspended solids, organic matter, fluorine, and trace heavy metals in the desulfurization wastewater can be effectively reduced, but the Ca in the treated wastewater 2+ , Mg 2+ , Cl - , SO 4 2- The content of Ca and so on is still high, and the Ca in the desulfurization wastewater 2+ , Mg 2+ , Cl - , SO 4 2- It is an effective method for soluble salts, long-term discharge will cause adverse effects on the environment, and it is also not conducive to the reuse of desulfurization wastewater after treatment

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