Ammonium adsorption-desorption by using sugarcane bagasse biochar

Abstract

Sugarcane Bagasse (SCB) was utilized into biochar by pyrolysis and used as adsorbent for ammonium removal. SCB biochar were produced at temperatures of 300 °C, 400 °C, 450 °C and 500 °C. Characteristics of biochar were analyzed by moisture content analysis, ash content analysis, Fourier Transform Infrared (FTIR) Spectroscopy and pH zero point change analysis. As the pyrolysis temperature increases, the moisture content of SCB decreases while the ash content of SCB biochar increases. The FTIR spectra of SCB biochar showed the organic part of SCB was mainly compound of lignin, cellulose and hemicellulose with different functional groups such as amides, alcohols, phenols, carboxylic acids, ethers and esters for ammonium adsorption. pH 7.0 is the pH value obtained for pH zero point charge analysis. The optimum adsorbent dosage is 0.05 g and the adsorption process reach equilibrium within 120 minutes with maximum value, 14.7142 mg/g for adsorption capacity of ammonium. For adsorption kinetic, pseudo-second-order model is more preferable than pseudo-first-order model because R2 value is 0.9944 where it is closer to 1, indicating chemical adsorption which involved valence forces by exchange or sharing of electrons between the SCB biochar and ammonium. For adsorption desorption of ammonium, SCB biochar is a good biochar where the adsorption-desorption process can run up to 5 cycles for biochar regeneration.