Molecular mechanisms of Ni(II) adsorption and Cr(VI) reduction by extracellular polymeric substances: Experimental evidence and density functional theory calculations - Mian Xu; Tiantian He; Ziqi Luo; Wenxuan Yang; Yingqi Dai; Yicheng Xie; Yibo Wang; Meng Niu; Di Cao (Journal of Environmental Chemical Engineering, 2026)