Photodegradation of methylene blue dye by hematite-biochar composite prepared from Dendrocalamus asper using microwave-assisted pyrolysis (MAP)

Abstract

Petung bamboo (Dendrocalamus asper) stem-based hematite-biochar composite (HBC) has been synthesized using microwave-assisted pyrolysis (MAP) to replace conventional pyrolysis. The bamboo sawdust contains 19.8-26.6% lignin and cellulose as much as 4.24-5.36% so that it can be used as precursors in biochar preparation. In general, bamboo-based biochar has a low adsorption capacity. In this study, biochar was modified by hematite (Fe2OH3) to increase its ability in dye removal through the photocatalytic-adsorption process. Biochar was prepared by the MAP process and impregnated with FeCl3 and Fe2SO4 compounds to produce HBC. The performance of HBC was then tested using methylene blue with variations in solution acidity level, adsorption duration, and starting concentration. The results show that HBC prepared using a MAP process has a higher adsorption ability (90.56%) than HBC prepared through a conventional pyrolysis process (84.85%). At an adsorption duration of 240 minutes and a solution acidity level (pH) of 9, methylene blue was best absorbed.