Layer-by-Layer Deposition of Titanium Dioxide Nanoparticles on Polymeric Membranes: A Life Cycle Assessment Study

Membrane processes are widely used in wastewater treatment and for removal of contaminants from drinking water. Engineered nanomaterials (ENMs) can be integrated into membranes structure to enhance their performance (e g, fouling mitigation and improvement of permeate quality). However, in order to ensure a sustainable use of nanoactivated membrane, the potential environmental impacts should be evaluated in an early stage of their development. In this study, we performed a cradle to gate life cycle assessment (LCA) to evaluate the environmental impacts due to the integration of titanium dioxide (TiO2) engineered nanoparticles (ENPs) in polyethersulfone (PES) membrane using the layer-by-layer (LbL) technology. The PES membrane manufacturing and electrostatic deposition of TiO2 ENPs on PES membrane were investigated in this case study. The results show that the LbL deposition stage of TiO2 ENPs on membrane has an insignificant effect on all selected impact categories, in comparison to PES membrane manufacturing stages investigated. The electricity use during the membrane production as well as the solvents and polymers needed for making PES membrane are the main contributions to the overall environmental impact.