Biochar is a carbonaceous substance made from any biomass, which may be utilized for resource recovery, pollutant reduction, soil fertilizer, etc., depending on the feedstock, thermal treatment condition, and the objective for application This brief review stresses the process of creating biochar from Municipal Solid Waste, which transforms into a value-added product that can also be used as green adsorbent to remove heavy metals from the wastewater. It highlights the potential of MSW as an adsorbent and addresses the important challenges for preparation, factors affecting the adsorption, different thermal pathways for biochar production, and various applications. It further investigates the complex mechanisms behind adsorption processes, including physical and chemical interactions that control the effective removal of Chromium (VI) under heavy metal criteria. Due to its high toxicity and carcinogenicity, Cr (VI) contamination has attracted attention. Numerous techniques tackle Cr (VI) removal from water, but adsorption reigns supreme for its cost-effectiveness and environmental friendliness. It employs diverse mechanisms like π–π complexation, electrostatic interaction, ion exchange, pore filling, and precipitation to remediate heavy metals (HMs).