Addressing the critical issue of global water scarcity requires sustainable solutions. This overview focuses on the synthesis, modification, and regeneration of chitosan-based porous carbon biosorbents derived from agricultural, forestry and agro-industrial biomass. The objective is to adopt eco-friendly biosorbents to enhance practicality and effectiveness in advanced wastewater treatment processes. The assessment will prioritize determining the ideal chitosan-to-porous carbon ratio for increased efficiency and selectivity in removing heavy metal ions and dyes from polluted wastewater. Furthermore, the development of porous carbon with a chitosan-based matrix yields a versatile and biocompatible adsorbent for sustainable wastewater treatment. Through extensive analysis of isotherms, kinetics, and thermodynamics, this overview aims to understand the adsorption behaviour of chitosan-based porous carbons. This review also highlights the potential advantages and challenges of using chitosan-based porous carbon for wastewater treatment, including aspects of regeneration and reuse. Moreover, it emphasizes wastewater reclamation and reuse for sustainable water resource management. © 2023 Elsevier Ltd