Exploring the role of activated charcoal from lignocellulosic biomass wastes for sustainable water treatment

For developing nations that are economically underdeveloped but have an abundance of biomass, using an affordable and effective heavy metal contamination treatment method based on biomass-activated carbon (AC) and other pollutants is obviously desired. Therefore, this review updates current studies that have used biowaste to adsorb pollutants such as heavy metals, dyes, and other adsorbates that are frequently encountered. Different biomass wastes were used to create AC using a two-step procedure that involved oxygen-free carbonization and activation. Compared with the more traditional physical/chemical activation approach, the microwave method has become more and more frequent in recent studies including the activation stage because it can ensure a more constant energy transfer in the biosorbents, resulting in enhanced surface area. Despite this, chemical activation is still frequently chosen due to its simplicity, affordability, and speed of setup. A detailed explanation of several other mechanisms for the adsorption of pollutants on biomass wastes-AC was also provided, including (i) surface binding capacity between metals and organic molecules (ii) electrostatic forces among oppositely charged ions, (iii) ion exchange between nucleophilic O ₂ functional groups as well as divalent metal cations (M ²⁺), (iv) physical metal adsorption & deposition. Additionally, important determinants of adsorption performance were thoroughly considered. Overall, this review gives an in-depth look at the manufacturing process of lignocellulosic AC and its use in water treatment, showing that biomass-based AC could have significant economic, environmental, and health benefits.