2.2.2. Analysis of products
The specific surface areas of samples were determined by the
surface area analyzer (V-Sorb 4800P) with N2 adsorptiondesorption
experiments at 77 K after the samples were pretreated
at 150 C for 5 h; The morphology change of clinoptilolite
before and after modified were observed using scanning electron
microscope (SEM) (JSM-6510A); The residual ion concentration in
the solutionwas analyzed by an inductively coupled plasma optical
emission spectrometer (ICP-OES); The crystal form of samples were
measured by X-ray diffraction (XRD) with the scanning range of
5e40; Framework vibration were analyzed by Fourier-transformed
infrared (FTIR) spectrometer in the range of
4000e550 cm1 range.; The binding energy and silicon aluminum
ligand structure were measured by X-ray photoelectron spectrometer
(XPS) and nuclear magnetic resonance (BRUKER AVANCE
III 400); Ammonia nitrogen analysis was carried out using the
nessler's reagent spectrophotometry method.