Permeability is the Critical Factor Governing the Life Cycle Environmental Performance of Drinking Water Treatment Using Living Filtration Membranes

Abstract

Living Filtration Membranes (LFMs) are a water filtration technology that was recently developed in the lab (Technology Readiness Level 4). LFMs have shown filtration performance comparable with that of ultrafiltration, far better fouling resistance than conventional polymer membranes, and good healing capabilities. These properties give LFMs promise to address two significant issues in conventional membrane filtrationfouling and membrane damage. To integrate environmental considerations into future technology development (i.e., Ecodesign), this study assesses the life cycle environmental performance of LFMs treating drinking water under likely design and operation conditions. It also quantitatively ranks the engineering design and operation factors governing the further optimization of LFMs' environmental performance using a global sensitivity analysis. The results suggest that LFMs' superior fouling resistance will reduce the life cycle environmental impacts of ultrafiltration by 25% compared to a conventional polymer membrane in most impact categories (e.g., Acidification, Global Warming Potential and Carcinogenics). The only exception is the eutrophication impacts, where the need for growth medium and membrane regeneration offsets the benefits of LFMs' fouling resistance. Permeability is the most important factor that should be prioritized in future R&D to further improve LFMs' life cycle environmental performance. A 1% improvement in the permeability will lead to a ~0.7% improvement in LFMs' environmental performance in all the impact categories, whereas the same change in the other parameters investigated (e.g. LFM lifespan and regeneration frequency) typically only leads to a <0.2% improvement.

Comparing the filtering efficiency of kombucha SCOBY and nitrocellulose membrane filter

“…Issue) : 2023 purity of the SCOBY can be used as a filtering material. The previous studies show that the 90% rejection of the 30nm particle, 98% rejection of 50nm particle, and 99% rejection of 100 nm particles was seen (Jiang et al, 2020). This shows it can remove most of the contaminants and some bacteria and protozoa.…”

Living Filtration Membranes Demonstrate Antibiofouling Properties

“…This study indicated that LFMs also experience an increased resistance to biofouling compared to a commercial MCE membrane. A publication using preliminary LFM and MCE data suggested that this resistance to fouling may reduce the life cycle environmental impacts of ultrafiltration considerably compared to commercial polymer membranes . In addition to filtration membranes, bacterial cellulose (BC) is also being investigated as a wound dressing, where BC grown from Acetobacter specifically may be useful for mitigating biofilms and infections within the field of medicine.…”

“…The LFM flux outperformed that of the commercial membranes by 19, 33, and 40%, as measured by the percent difference in flux decline after filtering 250 mL of water at constant pressure. LFM's resistances to fouling could considerably reduce the life cycle environmental impact of ultrafiltration compared to a conventional polymer membrane, 42 and this may translate to more successful applications of water filtration membranes in the future.…”