AWWA ACE60077

The Water Supplies Department (WSD), the Government of the Hong Kong Special Administrative Region(HKSAR) of the People's Republic of China (PRC) recently completed an investigation showing seawaterdesalination could be a secure, long-term source of freshwater and that reverse osmosis (RO) is the most cost-competitivemethod of desalination. As a result of this investigation, the WSD has undertaken a 30-month studyto establish technical, engineering, environmental, and budgetary information required to reach an informeddecision on how best to implement seawater RO desalination. The scope of the study includes: identifyingprospective plant sites and conducting pilot trials to define RO design requirements at two sites; identifyingthe most effective RO pre- and post-treatment processes; and, developing capital and operating cost estimatesfor one or more full-scale facilities.The pilot program is comprehensive and will involve testing for a continuous 12-month period at two separatelocations (24 months total) selected to represent the two types of water quality characteristics of Hong Kong'smarine geography: western region quality comprising variable salinity and turbidity influenced by runoff fromthe Pearl River; and, the eastern region more representative of open ocean water. Further, the program will includewater quality sampling at four additional marine locations to allow a comparison of water quality at sixdifferent areas of Hong Kong for future plant site considerations.A unique aspect of this pilot program will be the ability to assess the relative performance of microfiltration/ultrafiltration (MF/UF) with conventional granular media filtration for seawater RO (SWRO) pre-treatment.Each test site will be equipped with three individual SWRO trains, each of which is preceded by a different pretreatmentsystem. Pre-treatment systems to be simultaneously compared include pressurized MF/UF,submerged (or immersed) MF/UF, and two-stage granular media filtration. In addition, each SWRO train willinclude equal numbers of membrane modules from three different SWRO membrane manufacturers. Thiscombination will allow independent evaluation of each pre-treatment system in combination with each type ofSWRO membrane.This paper presents the many design issues considered throughout the site selection and pilot plant designprocess evaluated to provide WSD with the information necessary to cost and implement SWRO facilities andwill describe the piloting protocol, specific test objectives and the design and operation of MF/UF and SWROsystems used in the testing. The information will benefit utilities and the wider water industry who are interestedin how SWRO desalination can play a role in supplementing water resources and serve as an alternative supplyof potable water. It will also identify the issues and costs that must be considered in implementing adesalination program. Includes tables, figures, appendices.

Product Details

Edition:

Vol. - No.

Published:

06/17/2004

Number of Pages:

12

File Size:

1 file , 3.8 MB