The effect of zeolite treatment by acids on sodium adsorption ratio of coal seam gas water
ABSTRACT Many coal seam gas (CSG) waters contain a sodium ion concentration which is too high relative to calcium and magnesium ions for environment acceptance. Natural zeolites can be used as a cheap and effective method to control sodium adsorption ratio (SAR, which is a measure of the relative preponderance of sodium to calcium and magnesium) due to its high cation exchange capacity. In this study, a natural zeolite from Queensland was examined for its potential to treat CSG water to remove sodium ions to lower SAR and reduce the pH value. The results demonstrate that acid activated zeolite at 30%wt solid ratio can reduce the sodium content from 563.0 to 182.7 ppm; the pH from 8.74 to 6.95; and SAR from 70.3 to 18.5. Based on the results of the batch experiments, the sodium adsorption capacity of the acid-treated zeolite is three times greater than that of the untreated zeolite. Both the untreated and acid-treated zeolite samples were characterized using zeta potential, surface characterization, DTA/TG and particle size distribution in order to explain their adsorption behaviours.
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ABSTRACT: Oleic acid (OA) was hydrodeoxygenated in this study using zeolite-supported fluoropalladium oxalate (FPdOx/Zeol) catalyst. The FPdOx/Zeol was prepared via a pH controlled simple dissolution method and characterized with thermal gravimetric analysis, energy dispersive X-ray, X-ray fluorescence, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and Brunauer–Emmett–Teller techniques. The results showed that the deposited Pd particle was highly dispersed on the zeolite (Zeol) because of the presence of oxalate ligands and proper calcination. This observation was corroborated by the transformation of the Zeol support from crystalline into amorphous in FPdOx/Zeol as seen in the XRD and scanning electron microscopy results. The best experimental condition for the hydrodeoxygenation (HDO) of 3.5 g of OA was 370 °C, 20 mg of FPdOx/Zeol, and 100 mL/min of reducing gas (5% H2/N2) flow rate. The FTIR spectra of the evolved products at these conditions showed that the HDO of OA proceeded via the formation of stearic acid as intermediate product. A mixture of highly purified paraffinic fuel (iso-octadecane, 18%, and n-ocatadecane, 69%) was obtained after 44 min of HDO. The production of iso-octadecane which is an excellent fuel additive because of its antifreezing quality was due to the presence of fluoride ion in the FPdOx/Zeol. The FPdOx/Zeol demonstrated excellent qualities, and the results are promising toward further research and industrialization.Industrial & Engineering Chemistry Research 12/2013; 53(2):650–657. DOI:10.1021/ie4034158 · 2.24 Impact Factor
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ABSTRACT: Herein, for the first time, natural clinoptilolite-rich zeolite powders modified with a bio-inspired adhesive, polydopamine (PDA), have been systematically studied as an adsorbent for copper cations (Cu(II)) from aqueous solution. Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) revealed successful grafting of PDA onto the zeolite surface. The effects of pH (2-5.5), PDA treatment time (3-24h), contact time (0 to 24h) and initial Cu(II) ion concentrations (1 to 500mgdm(-3)) on the adsorption of Cu(II) ions were studied using atomic absorption spectroscopy (AAS) and neutron activation analysis (NAA). The adsorption behavior was fitted to a Langmuir isotherm and shown to follow a pseudo-second-order reaction model. The maximum adsorption capacities of Cu(II) were shown to be 14.93mgg(-1) for pristine natural zeolite and 28.58mgg(-1) for PDA treated zeolite powders. This impressive 91.4% increase in Cu(II) ion adsorption capacity is attributed to the chelating ability of the PDA on the zeolite surface. Furthermore studies of recyclability using NAA showed that over 50% of the adsorbed copper could be removed in mild concentrations (0.01M or 0.1M) of either acid or base.Journal of hazardous materials 03/2014; 273C:174-182. DOI:10.1016/j.jhazmat.2014.03.048 · 4.33 Impact Factor
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ABSTRACT: Graphene oxide (GO) nanosheets were grafted to acid-treated natural clinoptilolite-rich zeolite powders followed by a coupling reaction with a diazonium salt (4-carboxybenzenediazoniumtetrafluoroborate) to the GO surface. Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA) revealed successful grafting of GO nanosheets onto the zeolite surface. The application of the adsorbents for the adsorption of rhodamine B from aqueous solutions was then demonstrated. After reaching adsorption equilibrium the maximum adsorption capacities were shown to be 50.25, 55.56 and 67.56mgg(-1) for pristine natural zeolite, GO grafted zeolite (GO-zeolite) and benzene carboxylic acid derivatized GO-zeolite powders, respectively. The adsorption behavior was fitted to a Langmuir isotherm and shown to follow a pseudo-second-order reaction model. Further, a relationship between surface functional groups, pH and adsorption efficiency was established. Results indicate that benzene carboxylic acid derivatized GO-zeolite powders are environmentally favorable adsorbents for the removal of cationic dyes from aqueous solutions.Journal of hazardous materials 05/2013; 260C:330-338. DOI:10.1016/j.jhazmat.2013.05.041 · 4.33 Impact Factor