Adsorption-desorption of Malachite Green dye by using empty fruit bunch biochar

Abstract

Global industrialization has resulted in high amount of hazardous material discharges into wastewater. Biochar was found as one of the adsorbent for wastewater treatment. This study was conducted to analyse the capability of empty fruit bunch biochar on malachite green dyes adsorption. Biochar was characterized by ash content, moisture content, Fourier Transform Infrared (FTIR) analysis, Scanning Electron Microscope (SEM) analysis and pH zero point charge (pHzpc). Ash content increased meanwhile moisture content decreased as the pyrolysis temperature increased. pHzpc for empty fruit bunch biochar was at pH 7. The biochar produced at 500 °C was used as adsorbent for the adsorption of malachite green dyes. The effect of process parameters such as adsorbent dosage, adsorption contact time and initial concentration of malachite green dye were studied on the performance of malachite dyes adsorption. The results showed that maximum dyes adsorption capacity was occurred at pH 7 by using 0.01 g of empty fruit bunch biochar in 25 ppm of malachite green dyes solution for 120 minutes of contact time. The isotherms such as Langmuir and Freundlich were examined. Langmuir model is more favourable compared to Freundlich which indicates monolayer adsorption was occurred. For adsorption-desorption process of malachite green dyes, empty fruit bunch biochar showed as a good biochar which can run up to 5 cycles for biochar regeneration.