Materials
Secondary biological effluent and synthetic aqueous solution were used
in experiments. More details are in the Supporting Information (SI).
Ferric chloride (FeCl3·6H2O), ferrous
chloride (FeCl2·4H2O), polyferric
chloride (PFC), polyacrylamide (PAM),
ferroferric oxide (Fe3O4), potassium
nitrate (KNO3), and potassium sulfate
(K2SO4) were obtained from Sigma-Aldrich
(St. Louis, USA).
3-(trimethoxysilyl)
propyl-n -octadecyldimethyl ammonium chloride (TPODAC) was
purchased from Bailingwei (Beijing, China). Potassium dihydrogen
phosphate (KH2PO4) was purchased from
Macklin (Shanghai, China).