Functionalized Stink Bean Pod (Parkia speciosa) Powder for Adsorption of Reactive Dye

Abstract

The potential of agricultural waste materials for removing synthetic dye, Remazol Brilliant Blue R (RBBR) and Remazol Brilliant Violet 5R (RBV5) from aqueous solution were investigated. Water pollution is one of the major environmental issues; dyes have contributed enormous damage to water bodies and greatly impact human health due to high toxicity and carcinogenic by nature. Agricultural wastes are sustainable adsorbents and generally low cost, which has the potential to replace traditional activated carbon. Therefore, this study investigated the removal of RBBR and RBV5 dye from the aqueous solution by adding adsorbent through adsorption. Stink bean pod (Parkia speciosa) was selected as the main adsorbent of this study. The experiment was carried out to study the effect of different initial dye concentration, adsorbent dosage, contact time, and pH level of dye solution. The results have shown that different parameters can affect the removal rate and adsorption capacity of adsorbents in different ways. The adsorption of dye from aqueous solution onto adsorbent was assessed using Fourier Transform Infrared Spectroscopy (FTIR) to determine the functional groups of adsorbent before and after the adsorption process. The FTIR results show that the functional group would affect the removal rate and adsorption capacity of adsorbents. The present study indicates that 83.35% of RBBR with the adsorption capacity of 1.23 mg/g was removed by a 3 g stink bean pod. In comparison, 80.07% of RBV5 with the adsorption capacity of 1.22 mg/g was removed by a 3 g stink bean pod. Design-Expert software was used to generate the equation, which represents the behavior for the adsorption of RBBR and RBV5 dye. The results proved that stink bean pod was promising material as an alternative adsorbent for the removal of dye from aqueous solution.