Article

The effect of zeolite treatment by acids on sodium adsorption ratio of coal seam gas water

School of Chemical Engineering, The University of Queensland, Brisbane, QLD 4072, Australia.
Water Research (Impact Factor: 5.53). 07/2012; 46(16):5247-54. DOI: 10.1016/j.watres.2012.07.006
Source: PubMed

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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    • "It was proposed that this latter approach may provide a superior material in terms of the ability to remove ammonium ions from solution. This latter hypothesis was supported by previous work by Wang et al.[61]which demonstrated that careful treatment of natural zeolite with dilute acids could substantially improve the exchange of sodium ions from coal seam gas water samples. Factors thought to be beneficial included increase in zeolite surface area, enhancement of material porosity, greater dealumination, and a more negative zeta potential. "
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