ABSTRACT
The survival of pathogens in the environment has been extensively studied. Whereas some pathogenic organisms are able to persist in source water and žnished drinking water for days to months, they generally do not grow or proliferate in water (Fayer et al. 1998; Graczyk et al. 1999; Tamburrini and Pozio 1999; Wait and Sobsey 2001), with a few exceptions (e.g., Legionella, Vibrio, Naegleria, and Acanthamoeba). The survival of these pathogens is strongly related to water temperature, solar radiation,
4.1 Sources and Survival of Pathogenic Organisms ........................................... 107 4.2 Monitoring for Pathogens and Indicator Organisms .................................... 108 4.3 Microbial Considerations for Desalination Processes .................................. 109
4.3.1 Pretreatment ...................................................................................... 109 4.3.2 Blending Source Water with Desalinated Water .............................. 110
4.4 Reverse Osmosis ........................................................................................... 112 4.4.1 Integrity of the RO System ............................................................... 112 4.4.2 Fouling and Biofouling ..................................................................... 113
4.5 Organic Matter and Growth of Microorganisms in Desalinated Water ....... 114 4.6 Thermal Processes ........................................................................................ 114 4.7 Disinfection of Desalinated Waters .............................................................. 115 4.8 Storage and Distribution of Processed Water ............................................... 115 4.9 Issues with Blending Product Water with Other Sources ............................. 117 4.10 Recommendations ........................................................................................ 117 References .............................................................................................................. 118
osmotic pressure, and the abundance and activities of predators (e.g., protozoa). Increased water temperature results in an active development of the indigenous «ora and fauna, which utilize many microorganisms, including human pathogens, as food sources; this results in the accelerated removal of pathogens in warmer waters compared with waters below 15°C. Sunlight (ultraviolet light) has been identižed as an important factor in the inactivation of pathogens (Sinton et al. 1999; Fujioka and Yoneyama 2002). In addition, most human enteric bacteria also decay more rapidly in saline water than in fresh water as a result of the higher osmotic pressure (Nasser et al. 2003). Coastal currents and surface waves can transport pathogens over long distances (Kim et al. 2004; Reeves et al. 2004).
