Removal of Indigo Blue Dye from Aqueous Medium (or Industrial Effluent) using Chemically Treated Empty Palm Fruit Bunch Wastes

Abstract

Different treatment methods have been adopted for the removal of dyes from wastewaters in order to prevent or reduce their hazardous effects on living organisms and on the environment. This work was carried out on the empty palm fruit bunch fibers to investigate the effects of various chemical treatments on its ability to remove indigo blue dye from aqueous solutions. The untreated empty palm fruit bunches (UEFB) were subjected to three different chemical treatments (acetylation, mercerization and bleaching) geared towards improving specific properties such as surface morphology and thereafter, characterized by the scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The values of the maximum dye uptake (UEFB: 39.37 mg/mL; acetylation (AEFB): 84.75 mg/mL; bleaching (BEFB): 135.14 and mercerization (MEFB): 117.65 mg/mL) showed that all the treated fibers were able to considerably improve the sorptive ability of the adsorbent. The data obtained were well fitted to the Freundlich Isotherm while the Langmuir Isotherm could be applicable to UEFB. Chemical treatments of the fiber resulted in a reduction in change in enthalpy of the adsorption system and the modified fibers performed better than the unmodified fiber with BEFB which has the highest uptake of indigo blue dye and AEFB had the least uptake. The improved uptake is as a result of the chemical treatment that the adsorbents have undergone and this makes the bleached adsorbent with highest adsorptive ability suitable for treating indigo blue laden wastewater. The results obtained showed that chemical modification, such as mercerization and bleaching of adsorbents is a good means of improving the surface morphology and the uptake ability of the empty fruit bunch.