title: Reduction of highly concentrated phosphate from aqueous solution using pectin-nanoscale zerovalent iron (PNZVI).
abstract: Pectin-nanoscale zerovalent iron (PNZVI) has been studied as an effective phosphate adsorption material to remove highly concentrated phosphate from aqueous solution. Batch phosphate removal and equilibrium experiments were conducted in order to evaluate the effects of environmental factors such as pH, coexisting anions and ionic strengths on phosphate removal by PNZVI. The scanning electron microscope images of nanoscale zerovalent iron (NZVI) and PNZVI demonstrated that PNZVI exhibited larger specific surface areas than NZVI so that PNZVI had higher phosphate removal efficiency than NZVI. Equilibrium experiments showed that phosphate adsorption by PNZVI was well fitted with the Freundlich and Langmuir models. In addition, the maximum adsorption capacity reached 277.38 mgP/gPNZVI. The ionic strengths and common anions showed no significant effects on the process of phosphate adsorption by PNZVI. The phosphate removal efficiency increased to a peak value with pH increased from 2.0 to 5.0, then decreased with pH further increased from 5.0 to 10.0. The Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses of PNZVI and P-loaded PNZVI indicated that adsorption, rather than redox reaction, was the dominant mechanism for the removal of phosphate by PNZVI.
authors.affiliation: School of Civil Engineering, Wuhan University, Wuhan 430072, China E-mail: hongyuwangcc@126.com.
authors.forename: Hongyu
authors.initials: H
authors.lastname: Wang
authors.affiliation: School of Civil Engineering, Wuhan University, Wuhan 430072, China E-mail: hongyuwangcc@126.com.
authors.forename: Zhuocheng
authors.initials: Z
authors.lastname: Zou
authors.affiliation: Wuhan Engineering Consulting Bureau, Wuhan 430014, China.
authors.forename: Xuelian
authors.initials: X
authors.lastname: Xiao
authors.affiliation: School of Civil Engineering, Wuhan University, Wuhan 430072, China E-mail: hongyuwangcc@126.com.
authors.forename: Dan
authors.initials: D
authors.lastname: Chen
authors.affiliation: School of Civil Engineering, Wuhan University, Wuhan 430072, China E-mail: hongyuwangcc@126.com.
authors.forename: Kai
authors.initials: K
authors.lastname: Yang
mesh_terms: D000327:Adsorption; D007501:Iron / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D009994:Osmolar Concentration; D010368:Pectins / Q000737:chemistry*; D010710:Phosphates / Q000302:isolation & purification*; D056951:Photoelectron Spectroscopy; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D010710:Phosphates; D014874:Water Pollutants, Chemical; D010368:Pectins; D007501:Iron