title: Removal of ammonium and heavy metals by cost-effective zeolite synthesized from waste quartz sand and calcium fluoride sludge.
abstract: This study focuses on the effectiveness of zeolite (10% CF-Z [0.5]) hydrothermally synthesized from waste quartz sand and calcium fluoride (CF) for ammonium ion and heavy metal removal. Zeolite was characterized through powder X-ray diffraction, Fourier-transform infrared spectroscopy, micromeritics N2adsorption/desorption analysis, and field emission scanning electron microscopy. The effects of CF addition, Si/Al ratio, initial ammonium concentration, solution pH, and temperature on the adsorption of ammonium on 10% CF-Z (0.5) were further examined. Results showed that 10% CF-Z (0.5) was a single-phase zeolite A with cubic-shaped crystals and 10% CF-Z (0.5) efficiently adsorbs ammonium and heavy metals. For instance, 91% ammonium (10 mg L-1) and 93% lead (10 mg L-1) are removed. The adsorption isotherm, kinetics, and thermodynamics of ammonium adsorption on 10% CF-Z (0.5) were also theoretically analyzed. The adsorption isotherm of ammonium and lead on 10% CF-Z (0.5) in single systems indicated that Freundlich model provides the best fit for the equilibrium data, whereas pseudo-second-order model best describes the adsorption kinetics. The adsorption degree of ions on 10% CF-Z (0.5) in mixed systems exhibits the following pattern: lead > ammonium > cadmium > chromium.
authors.affiliation: College of Chemical Engineering, Huaqiao University, Xiamen, China E-mail: jmhong@hqu.edu.cn.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: College of Chemical Engineering, Huaqiao University, Xiamen, China E-mail: jmhong@hqu.edu.cn.
authors.forename: Bing
authors.initials: B
authors.lastname: Lin
authors.affiliation: College of Chemical Engineering, Huaqiao University, Xiamen, China E-mail: jmhong@hqu.edu.cn.
authors.forename: Junming
authors.initials: J
authors.lastname: Hong
authors.affiliation: Department of Environmental Engineering, National I-Lan University, Ilan, Taiwan.
authors.forename: Chang-Tang
authors.initials: CT
authors.lastname: Chang
mesh_terms: D000327:Adsorption; D064751:Ammonium Compounds / Q000032:analysis* / Q000737:chemistry; D002124:Calcium Fluoride / Q000737:chemistry*; D007700:Kinetics; D019216:Metals, Heavy / Q000032:analysis* / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D011791:Quartz / Q000737:chemistry*; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D014866:Waste Products; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry; D018508:Water Purification / Q000379:methods*; D014961:X-Ray Diffraction; D017641:Zeolites / Q000737:chemistry*
chemical_list: D064751:Ammonium Compounds; D019216:Metals, Heavy; D012996:Solutions; D014866:Waste Products; D014874:Water Pollutants, Chemical; D017641:Zeolites; D011791:Quartz; D002124:Calcium Fluoride