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Valley Center wastewater treatment facilitiesview Toray

Logo Toray large
Location: San Diego County, California, USA
Supplied by: Toray Industries, Inc.



MBR technology/system:


Flat Sheet (FS) MBR membrane configuration | Immersed technology configuration
Membrane material: Polymeric
Capacity range (MLD): 1.1 - 10.0
Visit the Toray MBR website

About Valley Center wastewater treatment facilities

Cost-effective Sludge Thickening Processor using MEMBRAY™ membrane bioreactor at
Valley Center, California

The Valley Center Municipal Water District (VCMWD) operates two wastewater treatment facilities in Valley Center, which is located in the northern part of San Diego County, California. These two sites are the Lower Moosa Canyon and the Woods Valley Ranch Water Reclamation Facilities (WRF).

Both WRF's incorporated an in-house membrane thickener (MBT) design and selected Toray's MEMBRAY™ Membrane Bioreactor (MBR) modules for the process. VCMWD's objectives were to conserve water and meet the Regional Water Quality Control Board's effluent standards (Title 22), so the reclaimed water can be used for irrigation and other reuse applications. The MEMBRAY™ MBR modules helped the local utility achieve these goals.

Using MBT has several economic advantages compared to other conventional methods of sludge thickening (i.e., rotary drums, belt press or filters):
• reduced footprint with the use of smaller tanks
• longer sludge retention time (greater than 100 days) leading to fewer costs associated with labor, energy consumption, chemicals for maintenance (cleaning is by air scouring for MBT and no need for polymers), and dewatering
• production of higher permeate quality and less reliance on additional treatment to meet water quality standards.

• The MBT tank is filled with Waste Activated Sludge (WAS) and with a pore size of 0.08 microns, MEMBRAY™ is an effective physical barrier while producing high-quality filtrate.
• The solids concentration in the MBT tank increases from 1% (10,000 mg/L) up to 3% (30,000 mg/L).
• Higher solids concentrations allow for longer retention time, which improves solids digestion.
• Improved digestion reduces bio-solids to be hauled, which translates into less labor and transportation costs.
• The Lower Moosa Canyon WRF required a centrifuge with a 40 hp motor to thicken solids. By integrating MEMBRAY™modules, only a 1.5 hp motor was required and considerably reducing energy costs.

View case study on company website

Company summary

Visit the Toray MBR website
Head office in Tokyo, Japan
Operates in Worldwide
commissioned plants Total installed capacity of 790,000 m3/day

About this page

This page was last updated on 25 March 2020


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