Metal Wastewater Treatment Technology - Electrolytic Method for High-Concentration Metal Recovery PART IV

Electrolytic Process

This is one of the more mature technologies applicable to the recovery of heavy metals when their ion concentration is high. Through oxidation-reduction reactions, heavy metals are precipitated at the cathode. It is suitable for high-concentration metal wastewater with high purity and simple components. However, this method is not suitable for final wastewater treatment, as it not only increases energy consumption but also cannot reduce the heavy metal concentration in water to below the standard. For example, in the case of high copper wastewater from a typical PCB printed circuit board factory, with copper concentrations ranging from 20,000 to 40,000 ppm, even with a recovery efficiency of 98%, the copper concentration in the treated wastewater still ranges from 400 to 800 ppm. Thus, it still requires subsequent treatment using other technologies to meet regulatory discharge standards. Therefore, the electrolytic method is particularly suitable for pretreating high-concentration metal wastewater in the front end. By electrolysis, the benefits of copper plate recovery are obtained, offsetting the initial and operating costs of the electrolysis equipment.

▲ Electrolytic recovery of high-concentration copper wastewater into copper plates has become one of the commonly used solutions today.