Synthesis of zeolite-P from coal fly ash derivative and its utilisation in mine-water remediation

Authors

  • Viswanath Vadapalli Department of Chemistry, University of the Western Cape
  • Wilson Gitari Department of Ecology and Resources Management, University of Venda
  • Annabelle Ellendt Environmental and Nano Sciences Group, Department of Chemistry, University of the Western Cape
  • Leslie Petrik Environmental and Nano Sciences Group, Department of Chemistry, University of the Western Cape
  • Gillian Balfour Environmental and Nano Sciences Group, Department of Chemistry, University of the Western Cape

Keywords:

acid mine drainage, circumneutral mine waters, fly ash, low temperature synthesis, solid residues, zeolite-P

Abstract

Solid residues resulting from the active treatment of acid mine drainage with coal fly ash were successfully converted to zeolite-P under mild hydrothermal treatment conditions. Scanning electron microscopy showed that the zeolite-P product was highly crystalline. The product had a high cation exchange capacity (178.7 meq / 100 g) and surface area (69.1 m2/g) and has potential application in waste-water treatment. A mineralogical analysis of the final product identified zeolite-P, as well as mullite and quartz phases, which indicated incomplete dissolution of the fly ash feedstock during the ageing step. Further optimisation of the synthesis conditions would be required to attain complete utilisation of the feedstock. The zeolite-P was tested for decontamination potential of circumneutral mine water. High removal efficiency was observed in the first treatment, but varied for different contaminants. The synthesised zeolite-P exhibited a high efficiency for the removal of heavy metal cations, such as aluminium, iron, manganese, zinc, copper and nickel, from contaminated mine water, even with repeated use. For potassium, calcium, strontium and barium, the removal was only efficient in the first treatment and decreased rapidly with subsequent treatments, indicating preferential adsorption of the other metals. A continuous release of sodium was observed during decontamination experiments, which decreased with subsequent treatments, confirming that sodium was the main exchangeable charge-balancing cation present in the zeolite-P product.

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Author Biography

Viswanath Vadapalli, Department of Chemistry, University of the Western Cape

Environmental and Nano Sciences Group, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa

Published

2010-06-09

How to Cite

Vadapalli, V., Gitari, W., Ellendt, A., Petrik, L., & Balfour, G. (2010). Synthesis of zeolite-P from coal fly ash derivative and its utilisation in mine-water remediation. South African Journal of Science, 106(5/6), 7 pages. Retrieved from https://sajs.co.za/article/view/10149