Studies on removal of Cu(II) from aqueous solution by adsorption on fly ash agglomerates

The objective of the present study is to assess the efficiency of the fly ash agglomerates (particle size: 2.5-5.0 mm) concerning Cu(II) removal from aqueous solution. The experiments have been carried out by using fly ash from brown coal and biomass burning power plant Zgierz (Poland). The tumble agglomeration experiments have been conducted in the laboratory granulator. Adsorbent dosage contact time and initial Cu(II) concentration on the adsorption were investigated. The maximum adsorption capacity achieved for fly ash agglomerates is 43.82 mg Cu(II)/g for 10 g/dm(3) adsorbent-to-solute ratio. For 1,000 mg/dm(3) Cu(II) solution the maximum removal was about 99% for 225 g/dm(3) adsorbent-to-solute ratio. The adsorption kinetics experimental data were fitted well with the pseudo-second-order model. An intra-particle diffusion model was examined. The Freundlich isotherm model is more adequate than the Langmuir or Dubinin-Radushkevich one while fitting the adsorption results of Cu(II) onto fly ash agglomerates at 25 degrees C. Column studies data were evaluated by using Thomas and Yoon-Nelson models. Fly ash agglomerates can be effective, low-cost, and easy-handling adsorbent for the removal of toxic Cu(II) ions from aqueous solution both in batch and column processes. To complement Cu(II) adsorption study was made FT-IR spectra.