Life cycle assessment of integrated multifunctional ultrafiltration and photovoltaic-reverse osmosis membrane systems for water reclamation

Abstract

There is an increasing interest in the sustainability of membrane treatment systems, notably for water and wastewater treatment through life cycle assessment (LCA) as it features the environmental performance of a system. The environmental burdens caused by the installation and operation of the membrane system must be examined to recommend environmentally acceptable technologies for future development. Environmental hotspots of membrane treatments are well-explored through LCA with various types of membrane processes and wastewater source but there are limited studies on an integrated ultrafiltration membrane or a combination of photovoltaicreverse osmosis (PVRO) technology. In this study, LCA was conducted to identify the environmental performance of two different membrane technologies treating two different types of water sources. The first technology analysed was an integrated ultrafiltration membrane with two different treatment processes as a pre-treatment: adsorption and electro-oxidation treating anaerobic-treated palm oil mill effluent (POME). The second technology was the PVRO technology as part of a desalination system in treating brackish water. ReCiPe 2016 method and SimaPro v9 software was utilised, adopting a ‘cradle-to-gate’ approach as the system boundary with consideration of midpoint and endpoint approaches. Results found that the hollow fiber membrane is the environmental hotspot for the integrated membrane, impacting significantly at 36% to 99% across all impact categories for both processes. Overall, the electro-oxidation process was discovered to have a lesser environmental impact, particularly on the ozone formation (human health) (HOFP) at 0.39 kg NOx eq in comparison to the adsorption integrated membrane at 0.66 kg NOx eq. The total characterization factor of the endpoint category for human health is 9.61E-04 DALY (adsorption integrated membrane) and 9.46E-04 DALY (electro-oxidation integrated membrane).