preparation of a novel polymer inclusion membrane based on industrial pvdf polymer for the extraction of the bismuth(iii)

Bismuth and its compounds have various medical and industrial applications. the abundance of bismuth ores is low therefore, the extraction/recovery of bismuth ions from other resources such as industry effluents is economically important [1]. various techniques such as precipitation, ion exchange, solvent extraction, adsorption and filtration membrane was employed for separation/ extraction of the metal ions from wastewaters [2]. among these methods membrane-based processes have attracted attention as a valuable technology. polymer inclusion membranes (pims) are a type of liquid membranes which have been widely used for purifying wastewaters, due to this method is environmentally friendly, high reusability, lower cost, selective and provide extraction and back extraction simultaneous [3]. pims are thin films that are formed by mixing an extractant, a base polymer and sometimes a plasticizer, in an organic solvent [4]. in this work, polymer inclusion membranes based on industrial pvdf polymer and tricaprylmethylammonium chloride (aliquat® 336) as ionic liquid extractant and dioctyl phthalate (dop) as plasticizer by casting evaporation method were prepared. the pim including 75 wt% pvdf, 20 wt% aliquat® 336 and 5 wt% dop selected as optimum composition because of its suitable physical and mechanical properties. bismuth extraction experiments were performed by immersing a 3.5 cm diameter round disk, with average mass 0.070±0.008 g and average thickness 49.7±5.7 μm, of the pims in a chloride solution containing 20 mg l-1 of bi(iii). the results showed that the pims can efficiently extract bi(iii) from 50 ml solution containing 20 mg l-1 of bi(iii) and 0.2 mol l-1 hydrochloric acid.