Comparative Phosphorus Removal Efficiency from Municipal Wastewater Using Acid Mine Drainage Sludge and Its H₂O₂Activated form As Adsorbents

Acid mine drainage (AMD) sludge is by-product from AMD treatment that formed by iron deposition. This sludge has a potential to be used as an active adsorbent to remove phosphate from domestic wastewater. The adsorbent that was used in this research is AMD sludge from PT Bukit Asam Tbk., Tanjung Enim that majorly composed of Si, Fe and Al compound (determined by the XRD test). Phosphate adsorption was done by AMD sludge and MD sludge that was activated by hydrogen peroxide. Activation process by hydrogen peroxide affected the chemical and physic characteristic of sludge and it showed from the results that the concentration of Si, Fe and Al were shifted by 7.33%, 7.03%, and 1.49%, respectively. Meanwhile for the physical characteristic; specific surface area, pore volume, and pore size were shifted by 19.51 m2/g, 0.0635 cm3/g, and 142.694 nm, respectively. Phosphate removal by AMD sludge has a greater result than activated sludge. Adsorption capacity of AMD sludge was well described by Freundlich isotherm model, which is equal to 6.358 mg P/g. Meanwhile, adsorption capacity of activated sludge was well described by Langmuir isotherm model, which is equal to 0.48 mg P/g. Results in this study indicated that the activation process with hydrogen peroxide affects the ability of phosphate adsorption that was showed by the difference of removal percentage.