A novel method in utilization of Bokbunja seed wastes from wineries in liquid-phase sequestration of Reactive Blue 4

Bokbunja seed wastes from a wine manufacturing industry were used to prepare carbon for the purpose of using it as an adsorbent for the removal of Reactive Blue 4 from aqueous solutions. A part of prepared carbon was treated with n-hexane to remove the seed oil present in large amounts in Bokbunja seeds. It was found that the hexane treated carbon was more efficient in removing the dye from aqueous solutions. Optimization of process parameters showed that pH 2 and contact time of 120 min was favorable for maximum adsorption. Langmuir and Khan isotherm models were applied to comprehend the adsorption process. Kinetic data showed that pseudo-first order model was a better fit than the pseudo-second order model. Alkaline pH favored desorption. Among the various desorption medium tested, acetone and ethanol showed promising results thus enabling the reuse of the carbon for next adsorption cycle. The study justifies the efforts to minimize the wastes by firstly using a winery waste as adsorbent and later reusing the same for the next cycle of adsorption in addition to recycling the desorption medium while simultaneously recovering the adsorbed dyes.