A kind of nickel-containing wastewater treatment method, treatment system and application

Abstract

The invention provides a nickel-containing wastewater treatment method. The treatment method is characterized by sequentially comprising the steps: (1) pretreating nickel-containing wastewater to obtain pretreated water; (2) performing biochemical treatment on the pretreated water obtained in the step (1) to obtain biochemical treatment water; (3) performing concentration treatment on the biochemical treatment water obtained in the step (2) to obtain concentration treatment high-salinity concentrated water and reuse water; (4) performing evaporative crystallization treatment on the concentration treatment high-salinity concentrated water obtained in the step (3) to obtain reuse water and crystal substances. Standards of the reuse water include that pH is 6 to 8, electric conductivity is smaller than or equal to 50, COD is smaller than or equal to 30, and turbidity is smaller than or equal to 1. The method has the advantages of simpleness in operation, stable operation, low cost and high treatment efficiency. Therefore, zero emission or low emission of electroplating production nickel-containing wastewater is achieved, and meanwhile higher-purity recycling on varieties of metal ions in the wastewater is achieved.

Description

technical field [0001] The present invention relates to a wastewater treatment method and a treatment system, in particular to a treatment method for nickel-containing wastewater in the electroplating industry, a system for treating nickel-containing wastewater in the electroplating industry that has used the method, and the method or the system in use Application in the treatment of nickel-containing wastewater in the electroplating industry. Background technique [0002] Nickel-containing wastewater treatment The commonly used methods in the wastewater treatment process are chemical precipitation, electrolysis and common ion exchange. The above treatment methods and systems all have certain limitations and cannot achieve zero discharge of nickel-containing wastewater. Among them, the chemical precipitation method is widely used in the treatment of nickel-containing wastewater. Due to the need to add a large amount of acid and alkali, ferrous sulfate, and polyaluminum chlo...

AI Technical Summary

Problems solved by technology

The above treatment methods and systems have certain limitations and cannot achieve zero discharge of nickel-containing wastewater

Among them, the chemical precipitation method is widely used in the treatment of nickel-containing wastewater. Due to the need to add a large amount of acid and alkali, ferrous sulfate, and polyaluminum chloride in the production process, the salt content of the wastewater discharge is increased, and the residues in the wastewater It is difficult for nickel ions to meet emission standards

Due to the extremely low content of controlled substances stipulated in the wastewater discharge standard, excessive chemicals need to be invested to meet the discharge standard, which is costly and the wastewater cannot be recycled as process water

At the same time, the chemical precipitation method cannot directly recover the nickel ions in the wastewater, and will produce a large amount of sludge, which contains a large amount of nickel ions, so the sludge needs to be treated again, causing secondary pollution; The waste water process is mature and the operation is stable. However, due to the extremely low content of controlled substances stipulated in the waste water discharge standard, the electrolysis method consumes a lot of electricity when treating nickel-containing waste water, the treatment cost is high, and it is easy to produce toxic gases, making it difficult to meet the standard. discharge; while the common ion exchange method is to use organic framework ion exchange resin to effectively remove various harmful ions in nickel-containing wastewater, and the treated wastewater can be reused, but the consumption of resin is large in the wastewater treatment process. It is difficult to deal with the regeneration solution, and it will also consume a large amount of acid and alkali, and the treatment cost is high

At the same time, the organic framework ion exchange resin will also cause a large number of resin ruptures during the regeneration process, which is not economical.

[0003] It can be seen that there are many problems in the various treatment methods for nickel-containing wastewater. Even if the existing equipment of each electroplating plant is fully utilized, most or all of the wastewater cannot be reused, and the value of the wastewater in the wastewater Metals cannot be effectively separated and recycled

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