Removal of thiocyanate ions from aqueous solutions using polypyrrole and polyaniline conducting electroactive polymers

Polypyrrole (PPy/Cl) and polyaniline (PAni/Cl) synthesized chemically onto sawdust (SD)was used for removal of thiocyanate (SCN-) ions from aqueous solutions. The effect of someimportant parameters such as pH, initial concentration, sorbent dosage, and contact time onuptake of SCN- was investigated. PPy/SD was found to be much more effective sorbent thanPAni/SD for uptake SCN- from aqueous solutions. Removal of SCN- ions using PPy/Cl issupposed to be occurred mostly via ion exchange process at the surface of polymer coated ontosawdust as a very thin film. Desorption studies were also carried out for figuring out thepossibility of the regeneration and reuse of the exhausted adsorbent. A proposed mechanismbased on interesting anion exchange properties of the PPy/Cl has been discussed. It was foundthat polypyrrole conducting polymers doped with releasable counterions can be used for used toremove some anions via ion exchange process under simple open circuit conditions. The findingin this paper shows the promising application of polypyrrole conducting polymers in future wateror wastewater purification technology.