Methods for the treatment of heavy metals in industrial wastewater

The source of wastewater containing heavy metals is produced in the production process of electroplating, mining, electronics, chemical and other industries. It mainly includes mine drainage, non-ferrous metal smelter dust removal and drainage, non-ferrous metal processing plant pickling water, electroplating plant plating washing water, as well as circuit board, electrolysis, pigment and other industrial wastewater. The types, contents and forms of heavy metal ions in wastewater vary with different production types. There's a big difference.

Heavy metal wastewater is one of the industrial wastewater with serious environmental pollution and great biological harm. Most metal ions and their compounds are easily adsorbed and precipitated by suspended particles in water.

Common treatment technology of heavy metal wastewater:

1. Heavy metal ions in wastewater are removed by chemical reactions, including neutralization precipitation method, sulfide precipitation method, ferrite co-precipitation method and chemical reduction method. Electrochemical reduction method and polymeric heavy metal trapping agent method.

2. Methods for adsorption, concentration and separation of heavy metals in wastewater without changing their chemical forms, including adsorption, solvent extraction, evaporation and solidification, ion exchange and membrane separation, etc.

3. Removal of heavy metals in wastewater by flocculation, adsorption, accumulation and enrichment of microorganisms or plants, including biological flocculation, biochemical method and plant ecological restoration.

4, heavy metal capture agent is a kind of chemical agent with heavy metal ion force chelation. It uses chelating groups on the branch chain to chelate heavy metal ions through the grafting synthesis process to form stable insoluble substances, so that metal ions can be removed from the water by precipitation so as to reach the standard discharge.