Recent trends in heavy metal removal technologies from water: mechanisms and advancements

Abstract

The relentless pace of industrial growth, as a direct result of the population boom, has consistently spawned consequential and often unmanageable issues, such as the pervasive problem of the release of toxic heavy metals into water. Among today's most critical environmental issues, heavy metal pollution has emerged as a severe problem. The predominant characteristic of heavy metals is their toxicity, exceptional solubility in aquatic environments, and the persistence of their ions without biodegradation, which causes specific issues regarding their potential accumulation within the human body through the food chain. The exposure of people and the environment to these toxic metals results in severe health problems. Additionally, reusing treated wastewater is the only solution for producing extra fresh water. The elimination of heavy metal ions from wastewater is crucial to uphold a clean environment and well-being of the people. A diverse array of approaches has been devised and put into practice for the treatment of wastewater, aiming to reduce heavy metal concentrations. These technologies cover membrane filtration, flotation, coagulation and flocculation, chemical precipitation, electrochemical processes, ion exchange, advanced oxidation processes (AOPs), and adsorption. Within this review, we present a detailed examination of important solution techniques that are necessary for discerning, workable and easily implementable wastewater treatment solutions for the elimination of heavy metals, thorough analysis of these methodologies, their mechanisms, their sustainability and their overall efficiency. Additionally, this review delves into the latest advancements and describes an array of approaches utilized for the elimination of heavy metals from wastewater by giving examples of pilot-scale processes used in some cases. It offers an insightful look into the ongoing commitments and technological breakthroughs that strive for more effective heavy metal removal and resource recovery from industrial wastewater. This review also examines various drawbacks and constraints in implementing these methods.