Problems of removing heavy metals salts from wastewater:
options and solutions

Summary

Many industrial enterprises generate large amounts of wastewater containing salts of various heavy metals and their compounds. Numerous technological options have been developed to extract heavy metals from wastewater: ion exchange and membrane technologies, as well as chemical methods. However, using the first two methods results in the generation of new highly concentrated solutions of toxic components that require subsequent landfilling or solidification. Chemical methods provide for obtaining waste in the form of sludge that also needs processing and landfilling. Consequently, these technologies are often combined. Some methods based on the intensive chemical precipitation in a vortex layer in the presence of seeding material, sand, as a rule, can be considered as an alternative. In this case, products of the process are granules, usually calcium carbonate, with heavy metals or other toxic contaminants bound in the carbonate layer. The developed dynamic water softening system (DSS), designed to remove carbonate hardness from drinking water, was tested for the purpose of removing non-ferrous metals. The results obtained allow us to expect the high efficiency of this method.

Key words

wastewater treatment , reagent methods , heavy metals , dynamic softening system , solubility of hydroxyls, carbonates and sulfides of salts of non-ferrous heavy metals , waste containment