UF pretreatment for SWRO: pilot studies

Development of an Environmental Impact Assessment and Decision Support System for Seawater Desalination Plants

“…In one case, no chemicals were injected into the UF-SWRO system, neither through the feed water nor the backwash water, which may be attributed to a sand filter preceding the UF [124]. In the other case, the UF-SWRO received its feedwater from a beachwell [118].…”

“…Of the 26 UF/MF pilot studies (Table 7), ten reported chlorine use in CEB only [98, 99, 102, 104, 107-110, 112, 123], and seven reported chlorine addition to the UF feed and CEB [101,[117][118][119][120][121][122]. The given chlorine doses to the feed water were 1 mg/l in winter and 2 mg/l in summer [117], which is comparable to the levels in the operational plants [e.g., a dosage of 1 mg/l results in a chlorine residual of 0.5 mg/l, 86].…”

“…For example, only a few papers in the recent literature explicitly stated that coagulants are not needed in their specific UF systems. This was either attributed to operating the plant at a 50% lower UF flux [86], to a beachwell intake [118] or additional media filtration [92,124] preceding the UF. Two of these papers reported results from pilot studies.…”

Seawater reverse osmosis desalination and (harmful) algal blooms

“…Over the last decade, UF membranes have been tested and applied at pilot and commercial scale as pretreatment for SWRO (Rosberg, 1997;van Hoof et al, 1999;Brehant et al, 2002;Glueckstern et al, 2002;Wolf et al, 2005;Halpern et al, 2005;Gille and Czolkoss, 2005) and are reported to offer several advantages over conventional pretreatment systems; namely, lower footprint, constant high permeate quality (in terms of SDI), higher retention of large molecular weight organics, lower overall chemical consumption, etc. (Wilf and Schierach, 2001;Pearce, 2007).…”

Study on the removal of biodegradable NOM from seawater using biofiltration

“…A considerable number of reports can be found in the literature associated with conventional and membrane pretreatments (Rosberg, 1997;Vial et al, 2003;Halpern et al, 2005;Bonnelye et al, 2008;Voutchkov, 2010, van Hoof et al, 1999Brehant et al, 2002;Pearce et al, 2004;Kumar et al, 2006;Xu et al, 2007;Lorain et al, 2007;Bonnelye et al, 2008;Shon et al, 2008;Salinas Rodriguez et al, 2009). Nevertheless, dosages of biocides (often chlorinated substances) are the currently employed common strategy to prevent biofouling because biocides can kill nearly all microorganisms.…”