Blast furnace slag of a ferrosilicon firm in aswan governorate, Upper Egypt, as an adsorbent for the removal of merocyanine dye from its aqueous solution.

The adsorption potential of the blast furnace slag of a ferrosilicon firm in Aswan Governorate, Egypt, to decolorize aqueous solutions of 3-methyl-1-phenylpyrazol-5-one 4[2] merocyanine dye (1) was investigated at room temperature. The influence of the solution pH, the quantity of adsorbent, the initial concentration of 1, and the applied contact time were studied with the batch technique. The maximum percentage of removal of 1 was observed at pH 4. The adsorption data were better fitted by the Freundlich than by the Langmuir adsorption isotherm model, confirming the formation of monolayers of 1 on the adsorbent surface. Kinetic rate constants and the transient behavior at different initial concentrations of 1 were determined with both the Lagergren pseudo-first-order and the Ho and McKay pseudo-second-order kinetic models. The calculated kinetic parameters revealed that the adsorption of 1 on blast furnace slag followed a second-order chemisorption process.