Biofouling of membrane systems:a manageable problem?

摘要

As a result of global increasing demands for high quality drinking water, the market for reverse osmosis (RO) and nano-filtration (NF) membrane technology has increased strongly in the last decade. One of the most serious operational problems in RO and NF nitration applications is biofouling - excessive growth of biomass (Figure 1) - affecting the performance of these membrane systems due to, e.g., an increase in pressure drop across membrane elements (feed-concentrate channel); a decrease in membrane permeability; or an increase in salt passage. These phenomena have resulted in the need to increase the feed pressure to maintain constant production and a need to clean the membrane elements chemically, as well as causing a decrease of the life span of the membrane modules (Figure 2). Biofouling influences the amount and quality of the fresh water produced, the reliability of water production and the costs.