Electrospun zein nanoribbons for treatment of lead-contained wastewater

Abstract

This paper reports the preparation of zein nanoribbons and their application in the removal of Pb(II) from polluted water. A modified coaxial electrospinning process was conducted permitting the smooth and continuous generation of zein nanoribbons. The process utilized sodium lauryl sulfate ethanol aqueous solution as the sheath fluid to overcome protein–metal interactions and the corresponding spinneret clogging. Scanning electron microscopic images demonstrated that the zein nanoribbons created using the modified processes had a flatter and narrower morphology than the analogous materials from a single-fluid process. By exploiting the favorable interactions between metal and protein, these zein nanoribbon mats were used to treat Pb(II)-polluted water. Adsorption results indicated that equilibrium was obtained in 60min for Pb(II) solutions with initial concentrations of 100, 150 and 200mg/L. The process can be described using the pseudo-second-order model. Isotherm data fitted well to the Langmuir isotherm model, with a maximum adsorption of 89.37mg/g. Desorption results showed that the adsorption capacity can remain up to 82.3% even after 5 cycles of re-use. Mechanisms underlying both the preparation and application of the zein nanoribbons were proposed.