Removal of Industrial Dyes using Biochar Derived from Tender Coconut Waste: A Review

The discharge of wastewater containing dyes, which is broadly produced by the textile, leather, and paper industries, is hazardous to both aquatic life and humans because of the toxicity of synthetic dyes and the complexity of dyes. Conventional treatment methods are expensive, are not effective in eradicating dyes, and generate secondary pollutants. Dye removal via adsorption, particularly using sustainable adsorbents, is a reliable process. The carbonbased product of biomass pyrolysis under low oxygen concentration has gained interest as an alternative to activated carbon; this is known as biochar. This review discusses the application of biochar prepared using tender coconut waste as an adsorbent for the removal of industrial dyes. This study examined the structure and benefits of tender coconut waste as a biochar feed and industrial dye, and its effects on the environment. A comparison of dye removal methods indicated the effectiveness and sustainability of biochar-based adsorption. The physicochemical characteristics of tender coconut waste biochar affecting dye adsorption, including surface area, pore structure, functional groups, and surface charge, were studied with reference to adsorption mechanisms such as electrostatic attraction, ?–? interactions, and pore filling. The benefits of tender coconut waste biochar in terms of its economic viability and circular economy were evaluated. This review concludes that tender coconut waste biochar is a sustainable option for the removal of industrial dyes, which will be included in the elaboration of the design of scalable dye removal systems.