Preparation of activated carbon from ion exchange resin waste and its application for manganese removal from groundwater

The present study aims to synthesize an activated carbon adsorbent (S-AC, P-AC and OH-AC) from polystyrene divinyl benzene waste under different carbonization temperature (450oC and 900 oC and activation conditions (H2SO4, H3PO4 or NaOH). It being characterized and applied as an adsorbent for manganese removal from groundwater. FTIR results indicate that the changes in the peak intensities clear that the binding process was occurring on the surface of the adsorbent. Different factors such as solution pH, adsorbent dosage, contact time, temperature and Mn(II) initial concentration were investigated. The results showed that manganese adsorption capacity decreases with the increase of the carbonization temperature (900oC) and of activating agent H2SO4 > H3PO4 >NaOH. Kinetically, it was shown that the activation temperature of 450oC is the best temperature for activating the adsorbent carbons. The pseudo-first-order model is appropriate for predicting the adsorption process of Mn(II) onto the P-AC 450oC, P-AC 900oC and OH-AC 900oC, while the pseudo-second-order model is appropriate for predicting the adsorption process of Mn(II) onto the both S-AC 450oC, S-AC 900oC, OH-AC 450oCand OH-AC 900oC. Thermodynamic calculations affirmed that Mn(II) adsorption onto S-AC and P-AC was an endothermic process while onto OH-AC was exothermic process. Finally, the results suggested that the prepared S-AC has high adsorption capacities for Mn(II) compared with other adsorbents, such as P-AC and OH-AC. Therefore, S-AC 450oCcan be used in the groundwater treatment unit.