Engineered microwave biochar from sago bark waste for heavy metals adsorption

Microwave pyrolysis is an energy, time, and cost-saving process for conversion of biowaste from agricultural sector into biochar. Sago bark waste was microwave pyrolyzed at 400 degrees C to produce sago bark microwave biochar (M-B), which was then treated with NaOH and HCl to generate acid-base modified sago bark microwave biochar (M-Bab). FTIR analysis evidenced the changes in functional groups in M-B and M-Bab. SEM analysis found that microwave pyrolysis resulted in the formation of open structures and pores on the M-B and acid-base modification increased the porous structure in M-Bab. BET surface area increased from 29.547 m(2)/g of (M-B) to 119.040 m(2)/g of (M-Bab) after acid-base modification. M-Bab demonstrated higher removal at low initial heavy metal concentrations in batch experiments. Best model to illustrate Cr (III), Ni (II), and Pb (II) adsorption by M-Bab best represented by Freundlich isotherm, while Cu (II) adsorption by Temkin isotherms. Conversion of sago bark waste to M-Bab is a potential solution for both water pollution remediation and the issue of sago bark waste overabundance. Copyright (C) 2021 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Symposium of Reaction Engineering, Catalysis & Sustainable Energy.