Zero emission recycling process for treating power plant desulfurization high-salinity high-hardness wastewater

Abstract

The invention discloses a zero emission recycling process for treating power plant desulfurization high-salinity high-hardness wastewater in the field of wastewater treatment. The process includes the following steps: chemically precipitating, using a solid-liquid separation membrane system, recycling condensate, specifically, charging concentrate of a nanofiltration membrane system into an MVR evaporator for evaporating and crystallizing, converting crystal into a bivalent salt for recycling, charging concentrate of a reverse osmosis membrane system into another MVR (mechanical vapor recompression) evaporating device for evaporating and crystallizing, and recycling crystal mainly including a monovalent salt. A desalting apparatus comprises a desalting membrane unit, a high-pressure pump, a membrane support, instruments, a pipeline and valves, and an electrical control system. The process of the invention has the advantages that floor area is small, resources are recycled, the whole process reduces energy and consumption, and zero emission of desulfurization wastewater is achieved.

Description

technical field [0001] The invention relates to a zero-discharge recycling process for treating desulfurization, high-salt and high-hardness wastewater of power plants in the field of sewage treatment. Background technique [0002] With the continuous deepening of the national environmental protection concept and the continuous strengthening of environmental protection measures, the requirements for wastewater discharge are also getting higher and higher. The impurities in the desulfurization wastewater of power plants mainly come from flue gas and limestone, and the wastewater contains a variety of metal ions. And F, C1, Cd, Si and other non-metallic pollutants. Desulfurization wastewater is generally weakly acidic, with a pH of 4 to 6, high content of suspended solids (suspended solids in desulfurization wastewater are mainly gypsum particles, silica, and hydroxides of iron and aluminum), high salt content, and high hardness. Among them, the cations are calcium, magnesium...

AI Technical Summary

Problems solved by technology

Although the amount of desulfurization wastewater is generally small, due to the complex and special water quality and strong corrosiveness, desulfurization wastewater is currently used for mixed dilution treatment or re-pouring into slag for adsorption and removal

However, due to the high-salt and high-hardness pollution characteristics of desulfurization wastewater, the dilution treatment has a great impact on other water treatment systems. During the treatment process, the hardness is high, it is easy to scale, and it is easy to corrode the equipment, resulting in unstable operation of the equipment.

And pouring into the slag furnace is also easy to severely corrode the slag furnace, resulting in a greatly shortened life of the slag furnace

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