Chemical and Polymer-Assisted Techniques for Heavy Metal Removal in Sustainable Water Treatment Systems

Abstract

Heavy metal contamination in water resources has emerged as one of the most critical environmental and public health challenges worldwide due to rapid industrialisation, urbanisation, mining activities, electroplating industries, textile processing, battery manufacturing, and agricultural runoff. Toxic heavy metals such as lead (Pb), cadmium (Cd), chromium (Cr), arsenic (As), mercury (Hg), nickel (Ni), and copper (Cu) are non-biodegradable and tend to bioaccumulate in living organisms, causing severe ecological and health-related consequences. Conventional treatment methods including chemical precipitation, ion exchange, coagulation, reverse osmosis, and membrane filtration often suffer from limitations such as high operational cost, sludge generation, low selectivity, and poor sustainability. Recent advancements in polymer-assisted and chemically engineered treatment systems have demonstrated remarkable efficiency in heavy metal adsorption, separation, and recovery from wastewater streams. This research paper presents an extensive analytical review of recent developments in chemical and polymer-assisted techniques for sustainable water treatment applications. The study critically evaluates adsorption mechanisms, nanocomposite polymers, functionalised hydrogels, biopolymers, conductive polymers, and hybrid treatment systems reported during the last five years. A proposed hybrid polymer-assisted adsorption model using chitosan-polyacrylamide-functionalised magnetic nanocomposites is presented for efficient heavy metal removal. Mathematical models, adsorption kinetics, equilibrium studies, pseudocode, comparative analysis, and AI-generated analytical charts are also incorporated to evaluate system performance. The proposed methodology demonstrates high adsorption efficiency, improved regeneration capability, reduced sludge formation, and enhanced sustainability compared with conventional systems. The research highlights the future scope of integrating artificial intelligence, smart sensing, and green polymer engineering into next-generation water purification systems for industrial and municipal wastewater treatment.