Recovery of Cobalt (II) through a Polymer Inclusion Membrane Based on Di Nonyl Naphthalene Sulfonic Acid

Recovery of cobalt(II) from aqueous solution by polymer inclusion membrane with dinonyl-naphtalenesulfonic acid (DNNSA) as the ion carrier and plasticized with 4 different plasticizer was investigated. Carrier concentration as an important parameter in recovery efficiency was studied and the membrane composed of 15% (wt/wt) of carrier was found to be the most efficient. The studies included effects of nature of plasticizers. Transport accross membranes plasticized with dioctyl adipate, dioctyl phthalate, triethyl phosphate, tributyl phosphate in 8 hours were investigated and dioctyl adipate was selected as the best. The FTIR characterization showed that the membrane constituents remains as pure substance after synthesis. Recovery of cobalt(II) ions increased with increasing of rate of mixing up to 200 rpm and after that became constant. The effect of pH on recovery was investigated between 3-7.5 and the most efficient pH was 5. Finally, the kinetics was studied with optimized parameters by investigation of cobalt concentration of source phase as a function of time and were found to follow first-order kinetics.