title: Synthesis of high capacity cation exchangers from a low-grade Chinese natural zeolite.
abstract: The Chinese natural zeolite, in which clinoptilolite coexists with quartz was treated hydrothermally with NaOH solutions, either with or without fusion with NaOH powder as pretreatment. Zeolite Na-P, Na-Y and analcime were identified as the reacted products, depending on the reaction conditions such as NaOH concentration, reaction time and hydrothermal temperature. The products were identified by X-ray diffraction, and characterized by Fourier transform IR and ICP. With hydrothermal treatment after fusion of natural zeolite with NaOH, high purity of zeolite Na-Y and Na-P can be selectively formed, their cation exchange capacity (CEC) are 275 and 355 meq/100g respectively, which are greatly higher than that of the natural zeolite (97 meq/100g). Furthermore, the ammonium removal by the synthetic zeolite Na-P in aqueous solution was also studied. The equilibrium isotherms have been got and the influence of other cations present in water upon the ammonia uptake suggested an order of preference Ca(2+)>K(+)>Mg(2+).
authors.affiliation: College of Biology and Chemical Engineering, Jiaxing University, Jiaxing, Zhejiang 314001, PR China. yifeiwang0206@yahoo.com.cn
authors.forename: Yifei
authors.initials: Y
authors.lastname: Wang
authors.forename: Feng
authors.initials: F
authors.lastname: Lin
mesh_terms: D000641:Ammonia / Q000302:isolation & purification*; D002412:Cations; D007475:Ion Exchange Resins / Q000138:chemical synthesis*; D008670:Metals / Q000032:analysis; D012972:Sodium Hydroxide; D012996:Solutions; D014867:Water / Q000737:chemistry; D017641:Zeolites / Q000737:chemistry*
chemical_list: D002412:Cations; D007475:Ion Exchange Resins; D008670:Metals; D012996:Solutions; D014867:Water; C083175:clinoptilolite; D017641:Zeolites; D012972:Sodium Hydroxide; D000641:Ammonia