Mechanism for phosphate removal and recovery in wastewater using the polyethyleneimine–ammonium molybdate system (PEI-AM): From adsorption precipitation to resource utilization - Jiaxiong Zhang; Jingtang Chen; Yanjie Chen; Yaoyue Zhang; Weixuan Xian; Qitang Wu; Zebin Wei; Rongliang Qiu; Ting Gao; Yangmei Chen (Journal of Environmental Chemical Engineering, 2026)