AWWA MTC69791

The City of Phoenix is planning the Western Canal Water Treatment Plant (WTP) to meetfuture population growth in the southwest planning area of the City. The major consideration for the watersupply in the area is the finished product water quality which will be impacted by the highlyvariable feedwater sources that would supply the water treatment plant. Of majorimportance to the project is the limited control the City will have over the water quality theyreceive at the WTP, and therefore must plan for significant operational flexibility in the processselection.The major treatment objective of the WTP is to provide a water supply that meets the Stage 2Disinfection/Disinfection Byproducts Rule and the Long Term 2 Enhanced Surface WaterTreatment Rule, and to remove Total Dissolved Solids to a target level of 700 mg/l. The system will use a combination of pretreatment solids removal, granularactivated carbon, microfiltration, primary reverse osmosis, lime precipitation processes on theprimary RO concentrate, concentrate treatment RO systems and ultimately concentrate treatmentsystems.In 2007, as part of the planning process for the WTP, the City embarked upon a 12 month pilotprogram to demonstrate the major process components. The pilot consisted of microfiltrationpretreatment (for surface water only), primary RO, solids contact lime clarification, andsecondary RO on the lime treated concentrate. This pilot study would build upon a previous high recovery RO pilot study as part of a Bureau of Reclamation project. The pilot system wasdesigned to operate on groundwater from a local well for a period of 3 months. Following theinitial 3 month test, the pilot would then be operated on a surface water supply and then return togroundwater for a final 3 month test. The initial bench testing for assisting in selection of theappropriate membrane was started in November 2007. Initial pilot testing started in April 2008and will be completed in early 2009.This paper discusses the design and current operation of the WTP Pilot System, and specificallyfocuses on the bench testing and pilot testing results for the RO systems. The paperhighlights the importance of a good pilot testing system design to match as closely as possible thefull scale system and how the pilot information will be used in the water treatment plant design. Includes 2 references, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2009

Number of Pages:

19

File Size:

1 file , 990 KB