Lida Rahmanzadeh; Mohsen Ghorbani; Mohsen Jahanshahi
Abstract
Mercury is one of the most toxic metals present in the environment. Adsorption has been proposed among the technologies for mercury adsorbent. The kinetics of adsorption depends on the adsorbent concentration, and the physical and chemical characteristics of adsorbent. In this study we were used a novel ...
Read More
Mercury is one of the most toxic metals present in the environment. Adsorption has been proposed among the technologies for mercury adsorbent. The kinetics of adsorption depends on the adsorbent concentration, and the physical and chemical characteristics of adsorbent. In this study we were used a novel adsorbent, magnetite-polyrhodanine core- shell nanoparticles, for removing Hg(II) from aqueous solution. The effect of pH, initial Hg(II) concentration, initial adsorbent concentration and contact time on the efficiency of Hg(II) removal were investigated systematically by batch experiments. The maximum adsorption capacity was obtained 29.14 mg g-1 at PH=6.5 and 25°C with 10 g L-1 nano adsorbent. The kinetic data of adsorption of Hg(II) ion on the synthesized adsorbent were best described by a pseudo- second- order equation, indicating their chemical adsorption. The Freundlich, Langmuir and Temkin isotherms were used to modeling of mercury adsorption on Hg(II) in aqueous medium which modeled best by the Freundlich isotherm is whole concentration rage.
Soodabeh Khalili; Ali Asghar Ghoreyshi; Mohsen Jahanshahi; Behnam khoshandam
Abstract
Multiwalled carbon nanotubes (MWCNT) were found to be an effective separation media for purifing CO2 from O2. Significant uptakes of CO2 and O2 were measured at 288 K, 298K and 308 K over the pressure range of 1 to 40 bar using volumetric method in dual sorption vessels. The same shape of isotherms ...
Read More
Multiwalled carbon nanotubes (MWCNT) were found to be an effective separation media for purifing CO2 from O2. Significant uptakes of CO2 and O2 were measured at 288 K, 298K and 308 K over the pressure range of 1 to 40 bar using volumetric method in dual sorption vessels. The same shape of isotherms introduced a common mechanism of adsorption but the amount of CO2 adsorbed on MWCNT is 2 times higher than O2 adsorption. The mass uptake of CO2 and O2 by MWCNT was found to increase with increasing pressure and decreasing temperature. The experimental data was well fitted by the Langmuir and Freundlich model isotherms considering the values of regression correlation coefficients. Following a simple acidic treatment procedure, CO2 and O2 adsorption was increased over range of pressure. The adsorbents was characterized by N2 adsorption isotherm at 77 K, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The effect of temperature and pressure on selectivity obtained from IAST demonstrated that maximum selectivity over the pressure and temperature ranges p = 0.5-5 bar and T = 298–308 K was achieved at 308 K and 5 bar.