Lead removal from aqueous medium using fruit peels and polyaniline composites in aqueous and non-aqueous solvents in the presence of polyethylene glycol

In the present study, composites of Polyaniline and some fruit peels were synthesized in various conditions and used for lead removal from aqueous solutions. Adsorption tests were conducted in batch mode using the most efficient adsorbent, and the effects of medium pH, initial lead concentration, contact time, adsorbent dosage, and adsorption isotherms were investigated. The results showed that all composites were more efficient in lead removal compared to the fruit peels alone. The highest removal percentage was related to the composite of banana peel and Polyaniline that synthesized in the aqueous solution in the presence of 2 g·L−1 Poly ethylene glycol. This composite showed 95.96% lead adsorption at pH=6, the contact time of 90 min, the initial lead concentration of 25 mg·L−1, and an adsorbent concentration of 8 g·L−1. Adsorption isotherm study showed that adsorption of lead by synthesized composite could be fitted by both Langmuir and Freundlich models, but the Langmuir model was more fitted than Freundlich. Besides, some characteristics of the composites, such as chemical composition (XRD analysis), structure, and morphology (SEM analysis) and functional groups (FTIR analysis), were studied.