Removal of colour from alkali extracted wastewater of Pulp and paper mill using fly ash as adsorbent

The study aims to explore the beneficial use of fly ash and its effectiveness as low cost adsorbent for wastewater treatment of Pulp and paper industry. A comparative study was also carried out for the better colour reduction of industrial effluent using fly ash and commercial activated carbon. Batch mode adsorption experiments were carried out to optimize the different experimental conditions like adsorbent dose, contact time, rotation per minute (RPM) and pH. The treatment showed that the removal efficiency of colour increased to 86 % with the increase in adsorbent dose (0.5 – 10 g), time (30–240 min), RPM (50 - 150) and pH (4–12) of pulp and paper industry wastewater. The removal efficiency of activated carbon was found to be 100 % using 1 g adsorbent dose of commercial grade activated carbon. The Scan Electron Microscope (SEM) results of the fly ash showed that the particles looked like somewhat spherical large particles. It was concluded that though the activated carbon was very efficient adsorbent in comparison to fly ash, the better solution for disposal of solid waste such as fly ash can be good a substitute as the adsorbent for the colour reduction of the paper mill wastewater.