Effect of agricultural residue-driven biochar application on biogas production during the two-stage anaerobic digestion of food waste | |
| Author | Sukanya Suttirat |
| Call Number | AIT Thesis no.EV-25-17 |
| Subject(s) | Crop residue management Biochar Sewage--Purification |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | Currently, the increasing consumption of agricultural products has resulted in significant food and agricultural waste, which poses environmental challenges. The open burning and disposal of this waste in landfills contribute to particulate matter and greenhouse gas emissions. However, these biomasses can be repurposed effectively. For instance, biochar, a material produced from agricultural waste, offers numerous benefits, including its applications in water treatment, anaerobic digestion (AD) and soil amendment. Additionally, food waste can be transformed into biogas through the AD process. Biochar has also been shown to enhance the efficiency of AD processes. This study investigates the impact of biochar on two-stage anaerobic digestion, particularly focusing on optimizing conditions to promote the production of volatile fatty acids and methane. The research utilized biochar derived from two types of agricultural waste: rice husks, referred to as rice husk biochar (RHB), and sugarcane bagasse, known as sugarcane bagasse biochar (SBB). Biochar was produced through pyrolysis at a temperature of 550 °C. Various concentrations of biochar were tested, specifically 2, 5, 8, 10, and 15 g/L, to assess their effects on methane production during the AD of food waste.The experimental results indicated that different types of biochar had different physicochemical properties, such as elements, pH, and functional groups. The experiment found that different amounts of biochar significantly affected biogas and methane production (p < 0.05). The use of SBB at 5 g/L resulted in the highest cumulative methane production, increasing by 32.31% compared to the control in the second phase. The use of biochar from rice husks showed that at 10 grams per liter, the highest cumulative methane production was 22% higher than the control. Biochar from bagasse produced more cumulative methane than biochar from rice husks. Four types of VFAs, namely acetic acid, propionic acid, butyric acid, and valeric acid, were generated as VFAs in the first stage. The system found the highest levels of VFAs on the fourth day. This VFAs resulted in the acidity and alkalinity of the system, which lowered the pH of the system. In addition, the addition of biochar provided a pH buffer and the adsorption of inhibitors, which stabilized the system. The addition of biochar in the experiment helped improve the kinetics of biogas. The use of biochar did not significantly affect the latent period during the experiment. |
| Keyword | |
| Year | 2025 |
| Type | Thesis |
| School | School of Engineering and Technology |
| Department | Department of Water Resources and Environmental Engineering (DWREE) |
| Academic Program/FoS | Environmental Engineering and Management (EV) |
| Chairperson(s) | Ghimire, Anish; |
| Examination Committee(s) | Ekbordin Winijkul;Singh, Jai Govind; |
| Scholarship Donor(s) | Her Majesty the Queen’s Scholarships (Thailand); |
| Degree | Thesis (M. Sc.) - Asian Institute of Technology, 2025 |