Activated carbon from wood wastes for the removal of uranium and thorium ions through modification with mineral acid

To prepare a highly efficient AC for removal of U(VI) and Th(IV) ions from water media, explosive property of NH4Cl was primarily recruited to exploit the sycamore wood (SW) wastes for production of an activated carbon (SWAC; AC) with highly ordered channels and high surface area, which was subsequently modified by treating with different mineral acid solution under microwave irradiation. After magnetization of acid-treated AC samples for easy separation from aqueous solution, the magnetized acid-treated AC (M-AcidAC) samples were examined to find the best conditions of both the activation process (NH4Cl/wood waste ratio, activation time and temperature) and acid treatment stage (acid normality, treatment time, and microwave intensity), using Taguchi experimental design and artificial neural network (ANN) analysis. The results disclosed that, among the mineral acids tested, HNO3 was superior for using in the treatment stage, since magnetized HNO3-treated AC (M-HNAC) showed higher sorption capacities towards the studied radionuclides. In addition, comprehensive study of sorption properties of M-HNAC towards U(VI) and Th(IV) ions vouchsafed that, using HNO3, inflicting an acid treatment stage on the SWAC is a beneficial path for preparation of a highly efficient sorbent for these radio-nuclides.