Deep treatment process for comprehensive wastewater containing heavy metals

Abstract

The invention relates to an advanced treatment process for comprehensive wastewater containing heavy metals. A system is formed by combining ion exchange resins with different functional groups and is used for advanced treatment of wastewater containing various heavy metals and various organic pollutants, especially wastewater containing various heavy metal complexes, such as comprehensive wastewater in the production process of electroplating or surface treatment parks, PCB and integrated circuits, large-scale nonferrous metallurgy production enterprises and the like. The heavy metal content of the wastewater treated by the method disclosed by the invention can meet the requirements of the highest industrial emission standards, such as the standard of a table 3 of an electroplating pollutant emission standard (GB21900-2008), special emission limits of a copper, nickel and cobalt industrial pollutant emission standard (GB25467-2010) and the like.

Description

Technical field: [0001] The invention belongs to the technical field of sewage treatment, in particular to an advanced treatment process for comprehensive wastewater containing heavy metals. Background technique: [0002] There are many kinds of wastewater pollutants produced in the production process of electroplating and other surface treatment industries, PCB and integrated circuit industries, and large-scale nonferrous metallurgical production enterprises, especially various heavy metal ions, which are far more difficult to treat than general industrial wastewater. In order to facilitate management and my country has concentrated most of the enterprises in industrial fields including electroplating surface treatment and integrated circuits in the park, but at the same time it has brought more types of wastewater pollutants and greater fluctuations in pollutant discharge, further increasing the cost of wastewater treatment. Difficulty, for the non-ferrous metallurgy industr...

AI Technical Summary

Problems solved by technology

Even though it is theoretically possible to use chemicals to remove most of the controlled substances such as heavy metals in wastewater, limited by the current detection technology, it is very difficult to track the concentration and flow changes of pollutants in real time. The amount cannot keep up with the changes in the concentration and amount of the controlled substance in time, either the effluent is not up to the standard, or the amount of the drug is excessive, which makes the treatment cost difficult to control

Therefore, the problem of using a single chemical method to treat comprehensive wastewater containing heavy metals is that it is difficult to achieve stable compliance with wastewater treatment standards.

Therefore, the chemical method can only be used as a pretreatment method. To achieve a stable depth of removal of heavy metal ions in wastewater, it must be combined with other treatment methods.

[0006] (2) Extraction method: the heavy metal ions in the wastewater are transferred to the organic phase containing the extractant by extraction, thereby removing the heavy metal ions in the wastewater, but the disadvantage of the extraction process is that the system is polluted by the extractant and solvent, Moreover, it is difficult to remove the heavy metal ion content in wastewater to a high standard

[0007] (3) Membrane method: the use of multi-stage reverse osmosis membrane (RO membrane), electrodialysis membrane (ED membrane), and nanofiltration membrane can reduce the content of heavy metal ions in heavy metal-containing wastewater to an extremely low level, but it will produce a large amount of Concentrates with high concentrations of metal ions, except for evaporation and concentration until the heavy metals become solid salts, these concentrates are difficult to be treated to discharge standards

For comprehensive wastewater containing heavy metals with complex components, there are problems such as easy pollution and poisoning of the resin, short service life, frequent regeneration, and gradual decline in resin exchange capacity, and there are almost no successful application cases.

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