Karakterisasi Biochar dari Berbagai Biomassa dan Studi Adsorpsinya terhadap Nitrat dengan Variasi Waktu Kontak dan Massa Adsorben

Abstract

Converting biomass to biochar is one of the attempts that can be carried out as a lignocellulosic biomass waste treatment. Biochar is a carbon-rich substance that has a large specific surface area and surface functional groups. Those characteristics of biochar make them have high potential to become an adsorbent. Some biomass waste that is quite plenteous in Kabupaten Jember are coconut shells, mahogany sawdust, and corn cobs. This waste treatment can be carried out using pyrolysis. Pyrolysis is one of thermal conversion method with limited oxygen and relatively low temperature. In this study, pyrolysis was carried out at 280-400℃ for 4 hours. The biochar then characterized by its surface area used BET and functional groups used FTIR. The study of adsorption on biochar begins with determining the optimum contact time and adsorbent dosage. Those data were used for biochar adsorption with various concentrations and to determined the adsorption isotherm model. The results showed that the optimum contact time of coconut shell biochar was 30 minutes, mahogany sawdust biochar was 45 minutes, and corn cob biochar was 35 minutes. The optimum adsorbent dosage of each biochar was 0,3 gram for coconut shell biochar and mahogany sawdust biochar, while 0,4 gram for corn cob biochar. The results showed that corn cob biochar has the best adsorption ability with Qe 2,19 mg/g during adsorption with optimum contact time and adsorbent dosage at 50 ppm. The isotherm models produces from coconut shell biochar, mahogany sawdust biochar, and corn cob biochar was Langmuir. The isotherm models show that the adsorbate forms a single layer (monolayer) on the surface of the adsorbent while adsorption process.