Advances in Electrochemical Techniques for Heavy Metals Removal: A Literature Review

Abstract

Heavy metal contamination is one of the major global environmental issues due to the toxicity, persistence, and bioaccumulation of lead (Pb), cadmium (Cd), copper (Cu), chromium (Cr), and arsenic. These pollutants from mining, electroplating, battery manufacturing, and industrial wastewater discharges threaten human health, ecosystems, and agricultural productivity. Chemical precipitation, adsorption, and membrane filtration are energy-intensive, wasteful, and ineffective for complex or low-concentration effluents. Selective removal, low chemical input, and resource recovery make electrochemical remediation a promising alternative. This review critically synthesises 43 peer-reviewed studies on electrocoagulation, electrochemical oxidation, reduction, electro-Fenton processes, and capacitive deionisation. Hybrid systems using electrochemical, biological, and nanomaterial-assisted methods improve efficiency and adaptability across wastewater matrices. Recent electrode material innovations like nano-zero-valent iron, carbon-based electrodes, and conductive polymers are reviewed to enhance system durability and performance—a detailed examination of energy demand, electrode fouling, material cost, and lack of real-world validation. Standardisation and field-scale testing address methodological gaps like inconsistent performance reporting and synthetic wastewater use. This paper builds a strategic framework for electrochemical heavy metal remediation using emerging technologies, digital optimisation, and circular economy principles. It is essential for environmental engineers, researchers, and policymakers seeking scalable, low-impact, and cost-effective heavy metal pollution control solutions.