An In-Depth Review of Sustainable Technologies for Heavy Metal Removal from Industrial Wastewater: Current Approaches and Prospective Challenges

Water sources contamination with heavy metals is a global source of anxiety. Heavy metals poses a real threat to ecosystems and human health. These metals such as lead, cadmium, and mercury are recognized as highly toxic and persistent pollutants due to their ability to accumulate in biological systems. This research explores and critically assesses cutting-edge technologies for the removal of heavy metals from industrial wastewater, aiming to reduce their harmful environmental and public health effects. The study first outlines the environmental and health hazards associated with these contaminants, followed by an overview of conventional treatment methods—including chemical precipitation, adsorption, ion exchange, and filtration. While these traditional approaches have proven effective, they are often hindered by the need for large quantities of reagents, as well as high operational and waste management costs. To address these limitations, the research shifts focus toward innovative treatment strategies, including nanotechnology, photocatalytic oxidation, advanced membrane technologies, and biological treatments. Recent literature is examined to highlight the performance, advantages, and limitations of these modern techniques. For example, nanomaterials demonstrate exceptional adsorption capabilities due to their high surface area, though challenges such as material recovery and economic viability remain significant. Similarly, membrane-based processes offer high efficiency but are often associated with high operational costs. The study also proposes strategies for overcoming these limitations, such as improving nanomaterial reuse and reducing energy consumption in membrane operations. A comparative analysis of the discussed methods is presented to support practitioners and researchers in selecting appropriate solutions based on factors such as contaminant characteristics, economic constraints, and technological readiness. Ultimately, this work aims to serve as a valuable resource for professionals and scholars engaged in industrial wastewater management, promoting informed choices and sustainable heavy metal remediation.