Enhancing Biogas Production from Chicken Manure: The Role of Acid-Pretreatment and pH Optimization

Recent research has focused on anaerobic digestion (AD) for resource recovery from organic waste, producing biogas as a renewable energy source. The increase in chicken manure (CM) production, driven by rising global chicken consumption, raises significant environmental concerns if not managed properly. Anaerobic digestion (AD) technology offers a solution by breaking down CM to produce biogas, which contains methane (CH₄) that can be used as renewable energy. This study focuses on CM's physical characteristics and the effects of acid- pretreatment and pH on biogas production through the AD process. Standard methods were used to measure the physical characteristics of CM, including total solids (TS), volatile solids (VS), and pH. The biogas production experiments were conducted in Duran bottles at a mesophilic temperature range of 26°C–32°C. Biogas production was measured using the water displacement method, with daily records taken over 5 days. The results show CM's total solids (TS), and volatile solids (VS) values were 34.39% and 70.14%, respectively, indicating its suitability for biogas recovery. To enhance biogas production, acid pretreatment (1%, 3%, 5%) and pH optimization (6.5, 7.0, 7.5, 8.0) were studied, revealing that 5% acid concentration produced the highest biogas yield (23,133.0 mL on day 5), while pH 7.5 resulted in the highest recovery (83,650.0 mL on day 5). These findings demonstrate that optimizing acid pretreatment and pH conditions can significantly enhance biogas production from CM. The study highlight’s. CM’s potential in renewable energy production and its role in reducing greenhouse gas emissions while providing economic benefits to poultry farmers in Sabah, Malaysia.