An investigation of the biological fouling in the filtration of seawater

This paper investigates the nature of the biological fouling of cartridge filters during the filtration of North sea water. Biological fouling is manifested through reduced filtration performance and short filter element life. The fouling of two different types of cartridge filter (coarse, 80 mu m and fine, 5 mu m) operated on an offshore oil production system was investigated over a two year period. The effect of seasonality on the accumulation of both organic and inorganic particulate material on both filter types was assessed. The results were correlated with the life of the elements in service. Filter life was found to be predominantly affected by the particle size distribution of the material within the seawater. Consequently, filter life was shortest during the spring and autumn, coinciding with the occurrence of the plankton blooms, and longest during the winter when the average particle size was larger. The presence of protein and lipid was found to contribute to filter fouling. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.