Two-stage activation of durian rind biochar for crystal violet dye removal from aqueous solution

The synthesis of biochar from by-products of the organic solid waste pyrolysis process presents a promising avenue of research. With its excellent porosity, biochar is highly effective in adsorbing harmful pollutants, including dyes. This study focuses on developing and evaluating the performance of biochar derived from durian rind waste as an adsorbent for the cationic dye crystal violet (CV). The biochar preparation involved chemical activation using 0.01 M HNO3, followed by physical activation through microwave-assisted drying (MAD). The resulting biochar demonstrated an adsorption capacity of q=6.844 mg g-1, with optimal performance observed at pH 9, an initial dye concentration of 70 mg L-1, and a contact time of 60 minutes using the batch method. Characterization of the biochar using FTIR and SEM revealed the presence of key functional groups (O-H, C=C, C-H) and a porous surface morphology. The biochar’s advantageous properties, such as its abundant raw material availability, cost-effectiveness, sustainability potential, and environmental friendliness, make it a suitable candidate for use as a sorbent in removing hazardous pollutants.