This study aims to explore the possibility of utilizing silica fume (SF) and coal fly ash (CFA), both of which are solid wastes and collected from producing silicon metal or ferrosilicon alloys and electric power station, respectively, as cost-effective adsorbents. Laboratory-scale experiments were carried out to investigate the adsorption equilibrium and adsorption kinetics of a xanthene dye Rhodamine B (RhB) on SF and CFA. Batch experiments were conducted to evaluate the effects of various parameters including contact time, temperature, adsorbent dosage, ionic strength, and solution pH on the adsorption capacity of the two selected adsorbents. Experimental result showed that the adsorption equilibrium was achieved within 150 min for each adsorbent and both of the adsorption isotherms could be well fitted to the Freundlich model. However, the adsorption capacity and removal efficiency of SF is nearly 4 times higher than that of CFA under the same conditions. Electrostatic interaction and cation exchange reaction play an important role on the adsorption process of RhB on SF and CFA. Desorption studies showed that 50% ethanol could be used as an effective extractant for the reuse of the adsorbents and recovery of the adsorbate. The two selected adsorbents have a potential in the application of the dye wastewater treatment.
ASJC Scopus subject areas
- Chemical Engineering(all)
- Industrial and Manufacturing Engineering