Adsorption experiments of vapor-phase elemental mercury were carried out by using bromine (Br) - and iodine (I)-modified kaolin

zeolite

bentonite and chitosan (CTS) in a laboratory-scale fixed-bed reactor.VM3000 online mercury analyzer was used to detect the inlet and outlet Hg0 concentrations.The characterizations of the sorbents were analyzed by using the method of nitrogen (N2) adsorption/desorption

X-ray fluorescence (XRF) technique and Fourier transform infra-red spectroscopy (FTIR).It was observed that the porosity and specific surface area decreased after modification.The FTIR spectra demonstrated that iodine was found in the internal layer of bentonite

and the chemical reactions of iodine and sulfate ion with the amide of CTS occurred.Fixed-bed adsorber tests showed that compared with kaolin and zeolite

the modified bentonite exhibited excellent mercury capture because of its unique structure.Mercury removal efficiency of CTS sorbents could be significantly enhanced when an appropriate amount of H2SO4 was added.Generally

the iodine-modified sorbents demonstrated higher mercury capture efficiency than that of bromine-modified sorbents.The mercury removal efficiencies ofthese sorbents increased with temperature.Bentonite’s capacity for mercury uptake decreased with the presence of moisture while chitosan’s capacity for mercury uptake exhibited an opposite tendency due to their absolutely different physicochemical properties.