Forward osmosis process for energy materials recovery from industrial wastewater with simultaneous recovery of reusable water: a sustainable approach

Abstract

In this study, a biopolymer-based forward osmosis (FO) membrane was used in combination with an easily recoverable and reusable draw solution (DS) for a simultaneous recovery of high-quality water and value-added products from industrial wastewater. Simultaneous wastewater dewatering resulted in a highly concentrated sludge that was reused as the electrode material. In this study, 86.92% dewatering was achieved using an easily recyclable mixture of ethylenediaminetetraacetic acid disodium (EDTA-2Na) with Triton X-100 micelles as the DS and a chitosan membrane with FO. The compatible membrane and the DS showed a flux of 5–6 L m−2 h−1 and a 0.008 ± 0.002 mol m−2 h−1 reverse solute flux with a retention of >99.0% for all organic pollutants from the chosen real-world wastewater. The recovered DS after the third use showed a >83.57% and >78.84% constant flux retention for deionizedand tannery wastewater as feed. In long-term tests with simulated wastewaters containing various contaminants, they showed >99.0% retention of organics and modern foulants and long-term stability (96 h). At the end of the FO process, sludge with different concentrations of organic wastes was recovered. The recovered solid sludge was carbonized (800 ⁰C) and used as the electrode material in a supercapacitor with a specific capacitance of 165 F/g at a current density of 0.5 A/g.