CHALLENGES IN THE CHEMICAL CLEANING OF UF MEMBRANES FOULED AT LOW TEMPERATURES

Abstract

Membrane separation technology is widely applied in water treatment; nonetheless, currently, there is no any established protocol for filtration and cleaning processes. This research attempts to study the nature of membrane fouling at low temperatures and select optimal conditions for chemical cleaning based on the membrane fouling propensity. Due to the complex nature of membrane fouling, it is difficult to predict fouling intensity and mechanism. Optimal chemical cleaning conditions could be selected based on the fouling mechanism parameters and membrane reaction to cleaning agents at different temperatures. From the literature review, it is clear that ultrafiltration process can successfully purify water from various contaminants through size exclusion mechanism and experiments were conducted with this process. In addition, the organic fouling remain as the major performance decline problem in membrane treatment processes. The protein fouling type (reversible or irreversible) and pattern is inquired through filtration experiments performed at different temperatures and chemical cleaning efficiency is investigated through membrane surface analysis. It was observed that, low filtration temperature affects membrane performance negatively by elevating fouling intensity, while high operation temperature demonstrated better water flux. Nonetheless, membrane surface investigation infers that high operation temperature affected membrane structure which can reduce membrane lifetime. These operation temperature influences must be considered in deciding convenient filtration process conditions based on preferred long-term operation or high water flux.