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Preparation Of MgAlFe Hydrotalcite-like Compounds And Research On Its Properties Of Adsorption Removal Of Phenol And 4-nitrophenol From Aqueous Solution

Posted on:2007-12-10Degree:MasterType:Thesis
Country:ChinaCandidate:Y Q WangFull Text:PDF
GTID:2121360185983809Subject:Environmental Engineering
Abstract/Summary:PDF Full Text Request
Mg (NO3)2·6H2O, Al (NO3)3·9H2O, Fe (NO3)3·9H2O,NaOH and Na2CO3 being raw materials, a sorbent Nano-Mg/Al/Fe Hydrotalcite-like Compounds (HTLCs) with differrent Mg/Al/Fe mol rations were prepared by co-precipitation method and different Mg/Al/Fe mixed oxides (HTLCs-500) were obtained by calcination of corresponding HTLCs. Both HTLCs and HTLCs-500 were characterized by all kinds of chemical analysis methods and the modern techniques. The structure and morphology of HTLCs and HTLCs-500 were studied by transmission electron microscope (TEM), X-ray diffraction (XRD), infrared spectroscopy measurements, TG-DTA and BET surface area. The ability of HTLCs and HTLCs-500 to remove phenol and 4-nitrophenol from aqueous solution was investigated. All the adsorption experiments were carried out as a function of time, pH, initial concentration of adsorbate, adsorbent dose etc. It was found that:(1) The optimum sorbent of this experiment is Hydrotalcite-like Compounds (HTLCs) and its calcined product (HTLCs-500) and the HTLCs sample prepared ishexagonal multilayer in structure, which is similar with the structure of hydrotalcite crystal. The diameter of particles is 3050nm. The HTLCs sample prepared contains a lot of-OH on the surface and there are CO32- anion at the interlayer of it.(2) HTLCs appearred little adsoption ability for phenol and 4-nitrophenol, while the adsorption ability of the calcined products (HTLCs-500) were found to increase, The HTLCs-500 obtained from HTLCs with Mg/Al/Fe mol ratio 3: 0.2: 0.8 calcined at 500℃ for 4h was showed to have the stongest adsorption ability. And the adsoption ability for 4-nitrophenol is more better than phenol.(3) By studying a function of time, pH, initial concentration of adsorbate, HTLCs and HTLCs-500 adsorbent dose etc. It was found that the maximum adsorption of HTLCs-500 for phenol takes place within 3 h at pH 7.0 and the adsorption data fitted well into the linearly transformed Langmuir equation., while the maximum adsorption of HTLCs-500 for for 4-nitrophenol takes place within 3h at pH 4.0 and the adsorption data fitted well into the Langmuir equation., both phenol are adsorbed on...
Keywords/Search Tags:Hydrotalcite-like compounds, Mixed oxides, characteristic, phenol, 4-nitrophenol, adsorption, mechanism
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