Studies on the Sorption of Basic Dye by Rubber (Hevea brasiliensis) Seed Shell

The present study investigated the ability of rubber seed shell (RSS) to abstract methylene blue (MB) from aqueous solution. The process of sorption of methylene blue from solution was analysed using 5 different isotherm models (Langmuir, Freundlich, Temkin, Harkins–Jura, and Halsey isotherm equations). The highest values of r2 were obtained when the experimental data were fitted into Freundlich and Halsey isotherm equations (0.999). The RSS/MB system was found to be affected by the sorbent dose and initial dye solution. The kinetic data showed that the sorption capacity of RSS for the dye increased with increasing initial dye concentration, while a reverse trend was observed when the effect of sorbent dosage was studied. Analysis of the data obtained from the different sorption studies revealed that the data fitted better to the pseudo-second order model than any other kinetic model, indicating that the sorption process will include chemisorptions of methylene blue dye on rubber seed shell.