title: Phosphate adsorption performance of a novel filter substrate made from drinking water treatment residuals.
abstract: Phosphate is one of the most predominant pollutants in natural waters. Laboratory experiments were conducted to investigate the phosphate adsorption performance of a (NFS) made from drinking water treatment residuals. The adsorption of phosphate on the NFS fitted well with the Freundlich isotherm and pseudo second-order kinetic models. At pH7.0, the maximum adsorption capacity of 1.03mg/g was achieved at 15°C corresponding to the wastewater temperature in cold months, and increased notably to 1.31mg/g at 35°C. Under both acidic conditions (part of the adsorption sites was consumed) and basic conditions (negative charges formed on the surface of NFS, which led to a static repulsion of PO4(3-) and HPO4(2-)), the adsorption of phosphate was slightly inhibited. Further study showed that part of the adsorption sites could be recovered by 0.25mol/L NaOH. The activation energy was calculated to be above 8.0kJ/mol, indicating that the adsorption of phosphate on NFS was probably a chemical process. Considering the strong phosphate adsorption capacity and recoverability, NFS showed great promise on enhancing phosphate removal from the secondary treated wastewater in the filtration process.
authors.affiliation: Department of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.; Zhejiang Provincial Key Laboratory of Water Science and Technology, Zhejiang 314006, China. Electronic address: wwd@xauat.edu.cn.
authors.forename: Wendong
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
authors.forename: Cui
authors.initials: C
authors.lastname: Ma
authors.affiliation: Department of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
authors.forename: Yinting
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
authors.forename: Shengjiong
authors.initials: S
authors.lastname: Yang
authors.affiliation: Department of Chemical and Biomolecular Engineering, Rice University, Houston 77005, USA.
authors.forename: Yue
authors.initials: Y
authors.lastname: Shao
authors.affiliation: Department of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
authors.forename: Xiaochang
authors.initials: X
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D060766:Drinking Water; D005374:Filtration / Q000379:methods*; D007700:Kinetics; D010710:Phosphates / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D060766:Drinking Water; D010710:Phosphates; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Adsorption; Domestic wastewater; Drinking water treatment residuals; Filter substrate; Phosphate