ABSTRACT
270The adsorption of reactive blue 21 (RB 21) on fly ash and MnO2-coated fly ash was studied in batch and column modes of operation. Various experimental parameters were studied including initial dye concentration (2.5-50 ppm), contact time, pH, and temperature (25-35°C). The experimental data were analyzed using Langmuir, Freundlich isotherm model. The adsorption RB 21 for fly ash and treated fly ash was found to follow Langmuir and Freundlich isotherm, respectively. The fly ash and MnO2-coated fly ash were characterized by scanning electron microscopy, X-ray fluorescence, and Brunauer-Emmett-Teller. The column adsorption experiments were carried out in glass columns, filled with fly ash and sand mixtures with different proportion (1:1, 1:2, and 1:3). Removal of dye decreases with the increase in solution concentration at room temperature, showing the process to be highly dependent on the concentration of the solution. It is concluded from the present study that MnO2-coated fly ash is a potential and active low-cost adsorbent for the removal of reactive dye from its aqueous solution and industrial wastewater.
