Phosphorus transformation in co-pyrolysis of biogas residue driven by intrinsic Fe/Mg in Fenton sludge: multi-scale mechanisms and enhancement of phosphorus bioavailability - Lei Ma; Hongxing Tu; Jingtong Li; Chunyang Chen; Liandong Zhu; Xiujuan Wang; Qianyi Cai; Junshi Tao; Jinrong Qiu; Zifeng Luo (Bioresource Technology, 2026)