Electrospun Keratin-Polysulfone Blend Membranes for Treatment of Tannery Effluents

Abstract

Due to the high toxicity of effluents radiating from tannery industries, there is a need for effluent treatment so as to limit its dangerous impacts on the environment. Fabricating responsive membranes is gaining significant interest in wastewater treatment applications. This study investigates the preparation, characterization, permeation, and antifouling properties of the keratin-polysulfone blend membranes. Keratin, a bioinspired material, is used as the responsive element along with the polysulfone matrix, which together acts as the responsive membranes for efficient filtration. Keratin was extracted from the goat hair, a tannery waste, through ball milling—an ecological, cost-effective, and time-consuming method. Keratin-polysulfone was blended in the ratio 95:5 (v/v) in their respective solvents to prepare nanofiltration membranes. The morphology of the membranes shows the random arrangement of fibers with the interstitial spaces. Contact angle measurements reveal that the keratin-polysulfone blend membranes are partially hydrophilic, which in turn resulted in good antifouling properties. Improved porosity of the fabricated membranes enabled good absorption capacity, and enhanced mechanical properties are an added advantage for the fabricated membranes. Since the membrane showed enhanced filtration property, the post-tanning effluents from the leather industry have been treated by the keratin-polysulfone fabricated membranes. The treated effluent showed a maximum percentage reduction in chemical oxygen demand (COD) and biological oxygen demand (BOD) concentrations of about 53% and 66%, respectively. The dye removal efficiency of the fabricated membrane is reported to be 76%. Thus, filtration efficiency has been established paving a way for treating effluents in an efficient way.