Method for deeply treating inorganic high-salt industrial wastewater and realizing zero liquid discharge

Abstract

The invention discloses a method for deeply treating inorganic high-salt industrial wastewater and realizing zero liquid discharge. The method comprises the following steps: treating alkaline waste residues, chemically removing hardness, precipitating and separating, carrying out double-membrane concentration and recycling according to different quality. The method disclosed by the invention has the beneficial effects that all the high-salt wastewater can be recycled and the zero liquid discharge is realized; calcium-containing alkaline waste residues (such as carbide slag and lime powder), carbonate-containing alkaline waste residues, waste gas containing carbon dioxide and the like are industrial wastes and comprehensive utilization of treating wastes by wastes is realized; the hardness is technically removed and the total hardness is reduced to be lower than or equal to 4mmol / L; scaling properties of the wastewater are reduced and the industrial wastewater is convenient to concentrate through low-pressure reverse osmosis; and particularly, according to different water quality of the high-salt industrial wastewater, different hardness removing materials and methods are adopted and the hardness removing cost is low.

Description

technical field [0001] The invention relates to the field of wastewater treatment methods, in particular to a method for advanced treatment of inorganic high-salt industrial wastewater and realizing zero liquid discharge. Background technique [0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. [0003] In prior art industrial production, after reverse osmosis treatment of inorganic waste water, clear water is reused as reclaimed water, concentrated water is hard to use due to the increase of dissolved solids, and most of the current industrial production can only be done according to environmental protection indicators. After reaching the standard, it is discharged to the environmental water body. With the continuous improvement of environmental protection requirements, "zero liquid discharge" has become an inevitable trend. Therefore, how to treat and utilize high-salt wastewater ...

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Problems solved by technology

[0004] Specifically, the evaporation method uses heat to heat and evaporate the wastewater. During the evaporation process, as the salt content of the wastewater increases, the fouling phenomenon gradually increases, which tends to reduce the heat transfer efficiency. Therefore, the process is complicated, and its energy consumption and The high investment in equipment also limits the use of this method;

[0005] The freezing method is to place the wastewater in a freezing field or a natural freezing environment. After the wastewater is frozen and the ice crystals are precipitated to a certain solid-liquid ratio, the frozen ice crystals are taken out, rinsed with clean water and dissolved, and the remaining wastewater enters a lower temperature cycle to concentrate. This method has a large investment in freezing treatment equipment, is subject to geographical restrictions, and has high costs.