Adsorption of thallium (III) ion from aqueous solution using modified ZnO nanopowder

In this study, the adsorption of thallium (III) ion from aqueous solutions onto modified ZnO nanopowder as a fairly low cost adsorbent has been investigated in batch mode. It was found that modification of the adsorbent was essential for obtaining the significant adsorption percentage. The adsorbent modified by sodium phosphate solution. The effect of experimental parameters such as initial pH of solution, contact time, adsorbent dosage, thallium initial concentration and temperature was studied. The results showed that the adsorption percentage was dependent on this parameters specially pH. The successful adsorption percentage of thallium (III) ion obtained at 25±1°C was 92.2- 92.6%. The equilibrium data could be well described by the Freundlich isotherm but its fitting by Langmuir model was not so successful. Separation factor, RL, values showed that modified ZnO nanopowder were favorable for the sorption of thallium (III) ion.