AWWA MTC69666

The Alameda County Water District (ACWD) draws from multiple water sources to meetcustomer demands, including desalinating brackish groundwater by reverse osmosis (RO)treatment. Together with CDM, ACWD just completed design of an expansion toBrackish Groundwater RO Desalination Facility that doubled the capacity to 12.5 mgd.The facility treats brackish groundwater with recovery rates of up to 80%. The treatmentfacility includes cartridge filters, chemical conditioning of the RO feed water,desalination by low pressure RO, air stripping to remove carbon dioxide (decarbonation),and miscellaneous chemical post treatment. The existing RO process includes two ROtrains, each with 42:21 arrays. Several factors were considered during the facility expansion design phase, including:manganese fouling, experience with the existing membranes including operation withimproving feed water quality TDS, treated water quality goals, reduced feed water aciduse, and RO feed pump selection to cover variable RO recovery rates and feed waterTDS. The design also incorporated other desired features including energy recoveryturbines, centralized pumping to pressurize the feed water to the four manifolded ROskids, V-port ball valves and globe valves to minimize noise and cavitation, andprovisions to allow the periodic chlorination of the decarbonators to minimize biogrowth. Includes tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2009

Number of Pages:

10

File Size:

1 file , 1.1 MB