Page 113 - Membranes for Industrial Wastewater Recovery and Re-Use

92 Membranes for Industrial Wastewater Recovery and Re-use

Figure 3.7 4 Electron micrograph of biofilm structure. The length of the white bar represents 10 km
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Jun-01 Jul-01 Sep-01 Nov-01 Dec-01 Feb-02
Sample Date

Figure 3.1 5 Seasonal variations in Legionella pneumophilia in cooling water (data from Raytheon
Corporation in St. Petersburg, Florida)

achieved by the addition of chemical dispersants to prevent particles from
aggregating and subsequently settling. Also, a secondary benefit of chemical
coagulation and filtration processes is the removal of some contaminants that
contribute to fouling.
The critical part played by biofouling in determining wastewater reuse
capability has been recognised in extensive studies carried out in Grangemouth,
Scotland (Glen, 2002). Grangemouth is one of the largest industrial complexes in
the UK, with major petrochemical industries concentrated in a small area. Water
consumption is 26 million m3 per year, costing business around $24 m per
annum at (2002 dollars), with one of the main uses being for heat exchange