Potential of Red Mud as an Adsorbent for Nitrogen and Phosphorous Removal in the Petrochemical Industry Wastewater

The increasing of nutrients in wastewater from petrochemical industry is mostly difficult to handle. Particularly, wastewater from this industry contains high level of nitrogen and phosphorus which may lead to eutrophication of algae bloom. In order to fully utilize the waste of bauxite (red mud) rather than to let it dumped to landfill without any treatment, a study was conducted to investigate the potential of red mud for nitrogen and phosphorus removal in petrochemical industry wastewater. The red mud (adsorbent) was modified with three different treatments; raw, heat-treatment and acid-treatment. Then, the adsorbent was characterized using Scanning Electron Microscopy (SEM). The maximum adsorption of nitrogen and phosphorus was observed by acid-treatment adsorbent; 68.75% and 63.16%, respectively. The equilibrium time was attained after 100 minutes. The highest removal percentage of nitrogen and phosphorus were achieved at adsorbent dosage 5 g/L with adsorbent size of 63 µm and inclusive rotational speed. SEM analysis found that morphology of pores increases when the adsorbents were treated with different treatment. Acid-treatment adsorbent was observed as an efficient and cost-effective adsorbent for selective removal of nitrogen and phosphorus in aqueous solutions.