Enhanced AGS by granular activated carbon loaded with nano iron when treating low strength and low COD/TN ratio municipal wastewater: Microbial metabolism, electron transfer and enhancement mechanism - Lei Peng; Haibo Li; Jianbo Guo; Jingfang Lu; Yanan Hou; Yi Han; Daohong Zhang; Yuanyuan Song; Jianhai Zhao (Journal of Environmental Chemical Engineering, 2024)