Production of Biochar from Rice Husk for the Immobilization of Heavy Metal

Abstract

Rice husk is a material prevalent in many climes of the world and continues to find uses to which it may be put after post-harvest treatment. Pyrolysis or carbonisation of rice husk is a thermochemical treatment that produces rice husk biochar, among other products. Rice husk biochar has proved to be a product that can be used in environmental remediation. In this study, rice husk biochar was produced in a two-step process, charred at an unstable temperature, and then pyrolyzed at a constant temperature of 400°C. Among the physiochemical properties examined, the product’s pH, surface area, and pore volume were determined to be 7.8, 247.639 m²/g, and 0.1384 cc/g, respectively. Scanning Electron Microscopy (SEM) was used to obtain the images showing the RHB's morphology and pore features. Biochar was used to treat contaminated water for lead (II) nitrate removal, and 76% removal was achieved in 6 hours. The rice husk biochar has shown the potential for its use as an adsorbent for environmental remediation where heavy metal is implicated.