Slow Pyrolysis of Waste Cow Bone for Biochar Production and Its Application in Copper Removal From Acidic Solutions

Abstract

This study presents a comprehensive analysis of bone char derived from cow bones, focusing on its characterization and potential applications in wastewater treatment. Cow bones, which are normally regarded as biowaste, were heated slowly to 300°C, 400°C, and 500°C, with a one-hour residence period and a heating rate of 10°C per minute, to produce biochar. The resultant cow bone char underwent extensive analyses to determine its physical and chemical properties. Elemental analysis revealed that the biochar is primarily composed of carbon. Nitrogen adsorption and desorption isotherms were employed to measure the specific surface area, pore size, and pore volume, with the highest specific surface area observed at 500°C, measuring approximately 77.31 m2·g−1, and an average pore diameter of 13.53 nm, indicating a predominantly mesoporous structure and exhibiting Type III isotherms. Functional group analysis identified the presence of various functional groups, including carboxylic acids, alkanes, and amines, which are effective for the removal of heavy metals from aqueous solutions. The adsorption capacity of the bone char for synthetic heavy metal copper in aqueous solutions was evaluated, revealing that the experimental data indicated the best fitting of the FL-PFO kinetic model and the Toth isotherm model, both demonstrating high correlation coefficients and minimal error values. These findings indicate that cow bone char has significant potential as an effective adsorbent for removing heavy metals from wastewater, offering a sustainable solution for managing biowaste and treating water pollutants.