Study On The Praparation Of Seaweed Biosorbents And Hybrid Materials Doped Ionic Liquid And Extractant And Their Adsorption Behaviors Of Metal Ions

Ionic liquids are typically comprised of organic cations. They are widely used as the replacements of the traditions volatile organic solvents (VOCs) in separation processes. In this paper, a new material (IL923SGs) composed of ionic liquids and Cyanex 923 for rare earths separation was prepared via a sol-gel method, both surface areas and pore volumes of IL923SGs were found to increase significantly. The hydrophobic ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate ([C8mim][PF6]) was used as solvent medium and pore templating material. Ionic liquid was stably doped into the silica gel matrix providing a diffusion medium for Cyanex 923, and this will result in higher removal efficiencies for metal ions separation. The combination of two separation mechanisms, solvent extraction and adsorption, was found to occur for the separation of RE(III) using IL923SGs. IL923SGs were also easily regenerated and reused in the subsequent removal of RE(III) in four cycles.Biosorption is a process that utilizes inexpensive active/dead biomass to sequester heavy metals and is particularly useful for the removal of contaminants from industrial effluents. Compared with conventional methods, the biosorption process offers the advantages of high uptakes, low operating cost, high efficiency and good selectivity. Marine brown algae Laminaria japonica was chemically modified by crosslinking with epichlorohydrin (EC1, EC2), or oxidizing by potassium permanganate (PC). Three prepared algae sorbents and Laminaria japonica only washed by distilled water (DW) were used for equilibrium sorption uptake studies with cadmium, copper, nickel, lead and zinc. Kinetics of metal adsorption was relatively fast, which could be described by first-order kinetic model. The metal adsorption was strictly pH dependent. Effect of solid/liquid ratio on metal biosorption was also investigated. A comparison of different isotherm models revealed that the combination of Langmuir and Freundlich (L-F) isotherm model fitted the experimental data best. The order of maximum metal uptakes for Cd(II), Cu(II), Pb(II) and Zn(II) was EC1 > EC2 > PC > DW, but the uptakes of Ni(II) are almost the same for these sorbents.