Journal of
Environmental Chemistry and Ecotoxicology

  • Abbreviation: J. Environ. Chem. Ecotoxicol.
  • Language: English
  • ISSN: 2141-226X
  • DOI: 10.5897/JECE
  • Start Year: 2009
  • Published Articles: 188

Full Length Research Paper

A study on removal characteristics of para-nitrophenol from aqueous solution by fly ash

Alinnor I. J.1* and Nwachukwu M. A.2
  1Department of Pure and Industrial Chemistry, Federal University of Technology, P. M. B. 1526, Owerri, Imo State, Nigeria. 2Department of Earth and Environmental Studies, Montclair State University, New Jersey, USA.
Email: [email protected]

  •  Accepted: 12 October 2010
  •  Published: 28 February 2011



The removal characteristics of para-nitrophenol from aqueous solution by fly ash were investigated under various conditions of contact time, pH and temperature. The influence of pH on the para-nitrophenol uptake by the fly ash was carried out between pH4 and pH 10. The level of uptake of para-nitrophenol by fly ash increased at higher pH values. The effect of temperature on the uptake of para-nitrophenol was investigated between 30 and 60oC; the adsorption increased at lower temperature. Rate constants were evaluated in terms of first-order kinetics. The rate constants k for uptake of different concentrations of para-nitrophenol was 1.10x10-2 s-1 and 1.14x10-2 s-1, respectively. The experimental results underlined the potential of coal fly ash for recovery of para-nitrophenol from waste water. The main mechanisms involved in the removal of para-nitrophenol from solution by fly ash were electron – withdrawing effect of NO2 group of benzene ring and adsorption at the surface of the fly ash.


Key words: Fly ash, para-nitrophenol, adsorption, kinetics, mechanism.