ENGINEERED BIOCHAR DERIVED FROM GRASS JELLY TREE WASTE

Abstract

The aim of this study was to prepare biochar from grass jelly tree, which is a solid waste of dessert industry, and investigate the effects of chemical modification with H3PO4 and ZnCl2 on the porous properties The grass jelly tree waste was pyrolyzed at 500, 600 and 700oC for 1 h to obtain biochar, and subsequently impregnated with 30 wt% H3PO4 or ZnCl2 for 24 h. Porosity measurements showed that the engineered biochar derived from pyrolysis at 700oC and modified with H3PO4 had the highest surface area of 111 m2/g. Furthermore, physicochemical properties such as bulk density, pH, pH at the point of zero charge (pHpzc), proximate analysis, compositions and morphologies of the biochars were further analyzed using different techniques including Scanning Electron Microscope with Energy Dispersive X-ray spectroscopy (SEM-EDX), X-ray Photoelectron Spectroscopy (XPS), thermogravimetric analysis (TGA) and Fourier Transform Infrared spectroscopy (FTIR). The engineered biochar with the highest surface area had a bulk density of 0.34 g/cm3, a slightly acidic pH of 6.21 and pHpzc of 6.9. This biochar had low moisture content of 5.69 wt% but high ash content of 26.61 wt%. The major component of the biochar was fixed carbon of 55.03 wt% which is in agreement with the SEM-EDX and XPS analysis. These results indicated the engineered biochar derived from grass jelly tree may be suitable for adsorption of organic and inorganic pollutants.