Removal of Brilliant Green Cationic Dye Using Bioadsorbent Material from Oyster Shells

This study explored the potential of coral rock, specifically coquina derived from oyster shells, as a bioadsorbent for the removal of dyes from wastewater generated by the textile industry. The investigation included an examination of particle size fractions (300 mu m and less than 300 mu m) and thermal treatment; the investigation involved drying at 120 degrees C and calcination at temperatures ranging from 200 degrees C to 800 degrees C. The material was subjected to a comprehensive analysis through various characterization techniques. Laboratory-scale experiments were conducted to evaluate the removal capacity and adsorption kinetics of the bioadsorbent utilizing brilliant green dye. The experiments involved varying dye concentrations (25, 50, and 75 mg L-1), pH levels (2 to 12), and different doses of biosorbent material (0.2 to 0.6 g L-1), with constant agitation. Various kinetic models were applied to fit the experimental data, with the pseudo-second-order model demonstrating the best fit. The findings reveal that coquina rock, characterized by a temperature of 120 degrees C and a particle size of greater than 300 mu m, exhibits remarkable effectiveness. It achieved a removal efficiency of 90% within 15 to 20 min at pH 7.8. This study concludes that coquina rock not only stands out as demonstrating remarkable efficacy in dye removal but also underscores a sustainable approach, leveraging readily available and environmentally friendly materials for wastewater treatment.