Physicochemical properties of biochar produced from biodegradable domestic solid waste and sugarcane bagasse

Authors

• Nguyen Xuan Loc * ¹
• Tran Duc Thanh ²
• Do Thi My Phuong * ³

1. Department of Environmental Science, College of the Environment and Natural Resources, Can Tho University, Can Tho 900000, Vietnam
2. Department of Environmental Science, College of the Envi-ronment and Natural Resources, Can Tho University, Vietnam
3. Department of Environmental Engineering, College of the Environment and Natural Resources, Can Tho University, Can Tho 900000, Vietnam

Abstract

Purpose This research aims to characterize the physical and chemical properties of biochar derived from biodegradable domestic solid waste and sugarcane bagasse, in order to evaluate their possible uses in agronomic and environmental applications.
Method Biodegradable domestic solid waste and sugarcane bagasse-based biochar were pyrolyzed at two pyrolysis temperatures (500 and 700 °C). Biochar properties included the determination of several physical and chemical parameters, i.e., pH, electrical conductivity (EC), cation exchange capacity (CEC), carbon content, iodine number, pH point of zero charge and surface morphology.
Results Under the investigated conditions, biochar properties were greatly affected by both pyrolysis temperature and feedstock type. The pH, EC, CEC, pH_pzc, iodine number and carbon content in biochar increased as the increasing pyrolysis temperature from 500 °C to 700 °C, whilst the opposite trend was found for biochar yield. Between the two biochar, at the same pyrolysis temperature, the sugarcane bagasse biochar possessed lower EC values (118.93 – 126.17 µS/cm) and carbon content (37.42 – 38.8%), but higher CEC values (18.62 – 20.12 cmol/kg) and iodine number (424.04 – 261.34 mg/g) than the biodegradable domestic solid waste biochar. SEM images of sugarcane bagasse biochar exhibited greater porosity than the biodegradable domestic solid waste biochar at both pyrolysis temperatures.
Conclusion The results implied that sugarcane bagasse biochar have better potential to be used in applications including the improvement of soil characteristics, the removal of contaminants from aqueous media, and the remediation of contaminated soil. To provide a better evaluation of the biochar’s performance, a further demonstration in soil or water test experiments should be conducted.

Highlights

• Biochar properties were affected by pyrolysis temperatures and feedstock, which could provide the possibility of tailoring biochar to specific environmental applications.
• For the same feedstock, the pH, EC, CEC, pH_pzc, iodine number and carbon content in biochar increased as the pyrolysis temperature increased from 500°C to 700°C.
• For the same temperature, the sugarcane bagasse biochar may be more suitable than biodegradable domestic solid waste biochar for soil amendment and nutrient adsorption purposes due to the lower in pH and EC values, but higher in CEC and iodine number.

Keywords

• Biochar
• Physicochemical properties
• Sugarcane bagasse
• Biodegradable domestic solid waste

Main Subjects

• Biochar