Removal of Chrome and Zinc From Industrial Wastewater Using Electrical Precipitation and Bentonite Clays

Abstract

This study deals with removal of (Cr and Zn) from industrial wastewater resulted from production processes in the State Company of Electrical Industries (S.C.E.I.). The removal process of these metals includes two stages; the first stage is the electrical precipitation of Cr and Zn metals, where Cr concentrations before and after performing this stage are 262 ppm and 26.6 ppm, respectively, while it is 1865 ppm and 45ppm for Zn. The second stage includes treatment with bentonite clay to remove the remaining concentrations of heavy metals in industrial wastewater to be within Iraqi standard specification for discharging in to river. Concentrations are < 0.1 ppm and < 1.0 ppm after applying this stage. These processes are suggested to be an alternative method to that in the State Company of Electrical Industries which uses the chemical precipitation that produce wastes with high concentrations of chrome and zinc, which stored in containers until discarded.