Arsenic adsorption enhancement performances of Mn-modified γ-Al2O3 with flue gas constituents involved.

ABSTRACT

Some flue gas constituents have negative effects on As2O3 adsorption of γ-Al2O3 so promoting arsenic adsorption performances under complicated flue gas conditions is necessary based on previous studies. In this study, γ-Al2O3 is modified with manganous nitrate and then Mn-modified γ-Al2O3 is used as the adsorbents in experiments. Besides, molecular dynamics (MD) simulations and density functional theory (DFT) calculations are performed to explore mechanisms of how loadings of Mn enhance arsenic adsorption features of γ-Al2O3 when being affected by flue gas constituents in microscale and mesoscale, respectively. As for DFT calculations, it is uncovered that electron transfer/interaction among As2O3, flue gas constituents and Mn-modified γ-Al2O3 mostly influences arsenic adsorption. For MD simulations, it is expounded that the collision and aggregation of As2O3 and flue gas constituent molecules have most impact on arsenic adsorption. As far as experiments are concerned, they are conducted to show the macroscopic characterizations of arsenic adsorption performances, corresponding to results of DFT calculations and MD simulations. The understanding of these three different aspects could supply significant references for utilization of Mn-modified γ-Al2O3 in real industries to remove arsenic under complex flue gas conditions.