Recovering electrical energy from forward osmosis process through amorphous silicon oxide crosslinked vanadium pentoxide-reduced graphene oxide membrane

Forward osmosis (FO) is a promising technology for energy-efficient water treatment but suffers from the drawback of reverse solute flux which often results in energy loss. Recent research has been directed toward reducing energy consumption and improving efficiency in the FO process. However, there remains a significant gap in utilization the inevitable reverse solute flux. Our study introduces an innovative approach to minimize energy consumption by transforming this reverse solute flux into sustainable electricity. Here, we fabricated membranes using two-dimensional flakes of vanadium pentoxide (VO) and reduced graphene oxide (r-GO) and cross-linked with amorphous silicon oxide (aSiO). The optimized VO-aSiO-rGO membrane showcases a remarkable ability to recover nearly 26% of the power applied for liquid pumping, exhibiting a significant advancement in the FO process. The membrane also outperforms commercial CTA-based FO membranes by achieving superior water fluxes (-45 L/m2.h) and low specific reverse salt fluxes (SRSF) (-0.13 g/L), indicating its superior separation efficiency for concentration applications. Moreover, the VO-aSiO-rGO membrane demonstrated stable performance with a water flux of 28.5 L/m2.h over 40 h of continuous operation. Additionally, it successfully generated output voltage and current values up to 293 mV and 32.2 & mu;A, respectively, with a 106 fold salinity gradient, leading to a power density of - 4.72 W.m 2. The study also explored energyrecovering possibilities and crystal production in realistic scenarios using different concentrations of tea as the feed solutions. The results of this work not only address the critical gap in the efficient use of energy in the FO process but also provide a significant breakthrough towards sustainable and efficient water treatment technologies with integrated energy recovery systems.