Microwave physicochemical activation: an advanced approach to produce activated biochar for palm oil mill effluent treatment

Empty fruit bunch (EFB) is an industrial waste that is abundantly available in Malaysia. Traditionally, EFBs were burned and dumped on the plantation site, resulting in global warming pollution from methane and carbon dioxide. In this study, the EFB was transformed into a high-surface area of activated biochar through a microwave physicochemical approach involving the combination of steam followed by a hydroxide mixture for palm oil mill effluent (POME) treatment. It was found that BET (Brunauer–Emmett–Teller) surface area and total pore volume of activated biochar were 365.60 m²/g and 0.16 cm³/g, respectively. The surface morphology of activated biochar revealed the formation of well-developed pores that can potentially be used as adsorbents to treat POME. The removal efficiency of biochemical oxygen demand (BOD) and chemical oxygen demand (COD) of POME achieved 75%–55%, respectively. This study offers insight into the transformation of industrial waste into value-added products for sustainable environmental remediation.