AWWA WQTC64105

To meet the water demands for Phoenix's growing population, a future 80-million gallon per day(mgd) water treatment plant (WTP), the Western Canal Water Treatment Plant (WCWTP), is being master planned to includedesalination of brackish surface and groundwater through a low-pressure reverse osmosis (RO)membrane system. This paper presents the development and evaluation of the membraneconcentrate management and disposal alternatives, and the City's short-term and long-termconcentrate management strategies. The study recommended that the City's membrane concentrate management anddisposal strategy for the proposed WCWTP consist of two steps.In the short term, membrane concentrate can be pretreated to remove Selenium, pumped via aforce main and blended with the 91st Avenue WWTP effluent prior to being reused at PVNGS.It is expected that the discharge of the concentrate, at the dilution ratio projected for the nearfuture, would not cause significant deterioration in the reuse water quality.In the long term, a ZLD concentrate management and disposal option will be implemented eitheron the Western Canal WTP site or at a centralized regional concentrate management facility. TheZLD option is proposed to include an initial volume reduction step using HPRO with andwithout chemical precipitation pending pilot results.The two-step strategy sets the long-term goal but allows the City to handle the short-term needswithin their planning budgets while protecting the environment and the sustainability of thewater reuse program. The deferral of the ZLD requirements allows the City to capture theemergence of more cost-effective options with the evolution of technology, when ZLD becomesnecessary. The additional benefit is that the concentrate is reused at the PVNGS that is expectedto be a major power supplier to the Southwestern United States. Includes 7 references, tables.

Product Details

Edition:

Vol. - No.

Published:

11/01/2006

Number of Pages:

9

File Size:

1 file , 4 MB