Surface Performance of Biochar from Young Coconut Shells (Cocos Nucifera) for Cd2+ Ion Adsorption

Abstract

Using agricultural waste such as young coconut shells could reduce environmental pollution and support the zero-waste principle. This study aims to prepare and analyze biochar from young coconut shells and determine adsorption ability. The biochar was prepared by pyrolysis with varying temperatures, 400°C, 500°C, and 600°C, and the resulting yield was 41.21%, 32.65%, and 29.79%, respectively. The biochar produced has met the Indonesian National Standard SNI 06-3730-1995 for moisture, ash, and the content of the amount of bound carbon in the biochar. Pore morphological characteristics and biochar elements were analyzed by Scanning Electron Microscopy-Energy Disperse Spectrophotometry (SEM) -EDS at 300x, 1000x, 3000x, and 10000x magnification. The pore size was 50 μm, 10 μm, 5 μm, and 1 μm with predominantly mass of element C 78.63%, atom C 85.18%. Atomic Absorption Spectrophotometry (AAS) measured the concentration of cadmium ions adsorbed using two variables; pH variable and biochar weigh variable. The absorption capacity in the pH variation indicates an increase in pH will increase the concentration of cadmium ions adsorbed, while the weight variation shows the fluctuated trend after 500 mg. The study showed an optimum biochar weight of 500 mg adsorbed 99.99% of cadmium ion. The pore size and the resulting carbon content, and the adsorption power of cadmium ions indicate that the biochar from young coconut shells has the potential to be developed industrially into activated carbon, which can be used as an adsorbent for industrial and domestic wastewater