Mechanistic insight into the ultrasonic-enhanced H2O2 advanced oxidation of refractory COD from molybdenum smelting waste acid under extreme acidity - Liuxin Xiang; Tao Xu; Qian Zhang; Tian Wang; Mingge Fu; Wenlong Miao; Thiquynhxuan Le; Libo Zhang (Journal of Water Process Engineering, 2026)