AWWA MTC57598

Seawater Reverse Osmosis (SWRO) desalination plants operating with surface open intakesrequire an efficient pretreatment to meet RO feedwater requirements. The objective of this studywas to assess the performance of ultrafiltration (UF) pretreatment prior to RO for the treatment ofhigh fouling potential surface seawater. A pilot plant equipped with Aquasource UF membraneswas operated in dead-end mode directly on Gibraltar harbor seawater. The efficiency of UFpretreatment was evaluated against conventional pretreatment with respect to downstream ROhydraulic performance.Results of the study illustrated that UF pretreatment yielded a very good and steady qualitypermeate, having a lower SDI value than permeate produced by simple one-stage dual mediafiltration pretreatment. The principal seawater components responsible for UF fouling was identifiedas organic matter released by planktonic organisms. Use of low dose pre-coagulation upstream ofUF helped to control this fouling potential, resulting in steady state hydraulic conditions and a lowcleaning frequency.The performance of RO membranes downstream of UF were evaluated under higher recovery andhigher flux rate operating conditions, to address the differential cost of UF as compared toconventional pretreatment, enabling SWRO plant design having reduced operating expenses andincreased ease of operation. Includes 12 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

03/05/2003

Number of Pages:

11

File Size:

1 file , 1.7 MB