Analysis of Electrochemical Technologies for Wastewater Treatment

Electrochemical technology has demonstrated significant advantages in water pollution treatment by virtue of its efficient redox reaction and flexible control characteristics. This paper systematically discusses the principles and applications of electrocoagulation (EC), electrooxidation (EO) and electro-flotation (EF): electro-flocculation generates hydroxide colloid adsorption of pollutants through the dissolution of the metal anode, and the removal rate of heavy metals (Pb, Cd, Cu) reaches more than 98%; electro-oxidation degrades difficult-to-biodegrade organics with the help of hydroxyl radicals (-OH), and the removal of dyestuff wastewater can reach over 98%. Electro-oxidation with the help of hydroxyl radicals (-OH) to degrade difficult-to-degrade organic matter, the COD and color removal rate of dyestuff wastewater is more than 80%; Electro-flotation using micro-bubbles to achieve high-efficiency separation of emulsified oils and colloidal particles. The synergistic process (e.g., EC-EF) can remove heavy metals and organics simultaneously, and the reduction rate of chromaticity and COD of printing and dyeing wastewater reaches 92.9% and 88.9%, respectively. However, the high cost of electrodes, high energy consumption and scale-up bottlenecks constrain its development. In the future, we need to focus on the development of low-cost electrode materials, multi-technology coupling (e.g., electrochemical-photocatalytic) and intelligent control, in order to promote electrochemical technology in the direction of zero industrial wastewater discharge and resource transformation, and help the sustainable management of water pollution.