Electrodialysis Treatment of Nickel Wastewater

Abstract

The galvanic processes are one of the main activities contributing to metal discharges into the environment. A large volume of wastewater is generated that contains a high load of salts and metals and it must be treated to recover the chemicals and water and save resources. Nickel is a toxic metal and causes various health problems. According to environmental regulations across the world, nickel concentrations in effluents must be controlled on an acceptable level before the discharge into the environment. The removal of metals by conventional treatment (chemical precipitation) not only does not result in a final effluent with a nickel concentration below the acceptable limit, but it also generates a large volume of galvanic sludge, a hazardous waste material. Several treatment processes have been suggested for the removal of nickel from rinse water, such as electrochemical techniques. This chapter presents the application of electrodialysis (ED) as an alternative that can contribute to comply with legal environmental standards and enable the recovery and reuse of water and chemicals in the nickel electroplating process, helping to minimize the environmental impact associated with the water consumption and generation of waste in the galvanic industry.