Abstract
A low-cost material with high adsorption and oxidation ability for Hg-0 capture is needed, whereas it is hard to prepare by present methods. Here, halide ions (I-) and metal oxides (MnOx and ZrO2) were both loaded on peanut shells carbon to synthesize 6Mn-6Zr/PSC-13. Various characterizations and experiments were used to investigate the physiochemical properties and Hg removal performances. The sample exhibited an abundant pore structure and the active components dispersed well on its surface. The excellent total Hg removal efficiency (more than 90%) was obtained in a wide reaction temperature range (150-300 degrees C) under a N-2 + 6% O-2 atmosphere. Moreover, the Hg adsorption capacity in 1440 min was 5587.0 mu g center dot g(-1) and the Hg-0 oxidation efficiency after reaching adsorption equilibrium was more than 30%. Further, the reaction mechanism at 150 degrees C was proposed. The main chemical adsorption sites of carbon-iodine groups dominate Hg-0 removal at the initial reaction stage. As reaction progresses, chemical adsorption is weakened due to the gradual saturation of adsorption sites, whereas catalytic oxidation caused by lattice oxygen and hydroxyl oxygen substitutes chemical adsorption and dominates Hg-0 removal at the final reaction stage. Thus, the 6Mn-6Zr/PSC-I3 with economic and environmental benefits has a promising prospect in industrial applications.