reported the simultaneous removal of SO2 and NOx using coconut shell based activated carbon prepared by KOH impregnation. In the study, KOH impregnation was found to be an important factor for increasing the simultaneous adsorption of SO2 and NOx. SO2 molecules were found to have higher affinity towardactive sites compared to NOx molecules, to form sulphates (SO4 2) and sulphites (SO3 2) .