title: Ammonium removal from aqueous solutions by using natural Chinese (Chende) zeolite as adsorbent.
abstract: This paper presents a study of the removal of ammonium ion from aqueous solutions using natural Chinese (Chende) zeolite. A series of experiments was conducted to examine the effects of solution pH, particle size, contact time, adsorbent dosage, and the presence of other cation- and anion species on ammonium removal. The findings indicated that these parameters named had a significant effect on the removal of ammonium by the zeolite. The effect of other cations on the removal of ammonium followed the order of preference Na(+)>K(+)>Ca(2+)>Mg(2+) at identical mass concentrations, and the effect of the presence of individual anions followed the order of preference carbonate>chloride>sulfate>phosphate at identical mass concentrations of ammonium ions. Kinetic analysis showed that the adsorption of ammonium on zeolite at different ranges of particle size well followed the pseudo-second-order model and followed the intra-particle diffusion model only during the initial 60 min of the adsorption process. Equilibrium isotherm data was fitted to the linear Langmuir- and Freundlich models with the latter model providing the better description of the process (R(2)=0.991-0.997) compared to the former (R(2)=0.902-0.989).
authors.affiliation: State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China. huanghaiming52hu@163.com
authors.forename: Haiming
authors.initials: H
authors.lastname: Huang
authors.forename: Xianming
authors.initials: X
authors.lastname: Xiao
authors.forename: Bo
authors.initials: B
authors.lastname: Yan
authors.forename: Liping
authors.initials: L
authors.lastname: Yang
mesh_terms: D000327:Adsorption; D000838:Anions; D002412:Cations; D006863:Hydrogen-Ion Concentration; D007477:Ions; D007700:Kinetics; D010316:Particle Size; D000644:Quaternary Ammonium Compounds / Q000737:chemistry / Q000302:isolation & purification*; D012996:Solutions; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods; D014867:Water / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*; D017641:Zeolites / Q000737:chemistry*
chemical_list: D000838:Anions; D002412:Cations; D007477:Ions; D000644:Quaternary Ammonium Compounds; D012996:Solutions; D014874:Water Pollutants, Chemical; D014867:Water; D017641:Zeolites