Environmental life cycle assessment of the microfiltration process

Membrane technology is being increasingly used in the treatment of waters and wastewaters. The two main costs associated with the adoption of membrane filtration are the membrane module cost and the energy cost. Tradeoffs between selection of membrane capital cost and energy cost are usually identified for process optimisation; however, environmental tradeoffs associated with different operating conditions have received less attention. In order to ensure the sustainable use of membrane filtration, environmental considerations should also influence the choice of operating conditions. Here, we report on application of the method of life cycle assessment (LCA) to assess the environmental performance of different operating conditions of a microfiltration membrane (MF) process. Different membrane chemical cleaning options are compared in the sensitivity analysis component of the study. The results show that operating the MF process at a low flux with a high maximum transmembrane pressure (TMPmax) offers the most environmentally favourable outcome. The sensitivity analysis results show that in the low flux range, the choice of chemical cleaning frequency can affect the overall environmental performance of the process.