Plane trees’ bark–derived porous biochar for efficient methylene blue biosorption

Abstract

Garden wastes such as leaves and bark are excellent biomass, which could be a potential source of biochar for purifying air or water. Taking the bark of the plane tree shed in summer as an example, a simple method for producing plane trees’ bark biochar by K₂CO₃ activation was presented. The method had advantages such as activation and carbonation in one step to prepare biochar. Research results showed that the prepared biochar had a large specific surface area of about 1193.290 m²/g. Then, the adsorption kinetics study revealed that the quasi-second-order kinetic model better described the adsorption process. Moreover, the adsorption process was better described by the Freundlich model. The maximum adsorption capacity of 1123 mg/g was in the range of 100–250 mg/L of MB. The main adsorption mechanism might involve hydrogen bonding, π-π* stacking, electrostatic interaction, and pore filling. This method could be utilized for the preparation of other types of activated carbon to ensure the efficient and comprehensive utilization of biomass.