<p>Water pollution caused by both organic and inorganic contaminants has emerged as a critical global concern, promoting the need for effective and environmentally sustainable treatment solutions. Among the promising approaches, biomass derived activated carbon and chitosan hydrogels have attracted significant attention due to their renewable origins, strong pollutant adsorption abilities, and adaptable properties. Biomass-derived activated carbon is particularly valued for its exceptionally large surface area and high affinity towards wide range of contaminants making it a cost effective and sustainable choice for water purification. Meanwhile, chitosan hydrogels stand out for their natural biocompatibility and can be easily modified to suit specific treatment needs. This review highlights recent advances in developing composite materials that merge activated carbon with chitosan hydrogels, focusing on synthesis routes, structural features, and their performance in wastewater remediation. It examines fabrication methods designed to improve mechanical strength and adsorption efficiency of these composites, along with operational factors such as pH levels, temperature, initial pollutant concentration, dosage of adsorbent, and ionic strength that influence adsorption behavior. The combination of activated carbon with chitosan hydrogels demonstrates synergistic benefits, including superior adsorption capacity and faster pollutant removal rates. The review also discusses ongoing challenges such as material durability, ensuring regeneration, and outlines future research directions to support the broader application and scalability of these materials. By consolidating current findings and identifying gaps in knowledge, this review provides a detailed and insightful perspective on the potential of biomass-based activated carbon and chitosan hydrogels as sustainable tools for environmental remediation.</p> Graphical abstract <p></p>