Synergistic effects and mechanisms of ultrasonic, pH, and peracetic acid pretreatment on sludge anaerobic fermentation to stimulate short-chain fatty acid production - Eid S. Gaballah; Lei Gao; Richen Lin; Mahmoud M. Ali; Biao Yang; Mostafa Sobhi; Chongpeng Tang; Guangcan Zhu (Bioresource Technology, 2025)