“MICROFILTRATION AND REVERSE OSMOSIS PILOT TESTING FOR INDIRECT POTABLE REUSE AT THE UNIVERSITY AREA JOINT AUTHORITY”

As part of the implementation of Beneficial Reuse for the Centre Region of Pennsylvania, the University Area Joint Authority (UAJA) conducted long-term pilot testing of microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) equipment. The pilot testing facility was constructed to determine the feasibility of reclaiming 3.0 Million Gallons per Day (MGD) of secondary effluent from the existing UAJA wastewater treatment facility for the purposes of water reuse and streamflow augmentation. This pilot testing, and its associated analysis, is known as the Phase I Microfiltration Pilot Testing and Phase II Nanofiltration/Reverse Osmosis Pilot Testing for the Beneficial Reuse Project. The Phase I Pilot Testing was conducted from November 1999 through March 2000, and the Phase II Pilot Testing began in May 2001 and will continue through December 2001.The Beneficial Reuse Project is the selected alternative of the Centre Region for the treatment and reuse of the additional 3.0 MGD of wastewater expected from growth and infilling of the existing UAJA sanitary sewer service area during the period of 2002 to 2020. As part of an ongoing analysis by UAJA, the Phase I and Phase II Pilot Testing served multiple purposes. These include permitting of advanced wastewater treatment technologies, equipment procurement and competitive bidding processes, and public relations and education.The Phase I Pilot Testing evaluated Microfiltration Units from numerous manufacturers, and eventually operated full-scale pilot units from U.S. Filter/MEMCOR, Pall Corporation, and Koch Membrane Systems. These units were operated for a period in excess of three months and were monitored by plant personnel and manufacturer's technical staff. Operational data, including flux, transmembrane pressure (TMP), and reject flows, were maintained and utilized to verify performance. The data was then used to complete a present worth analysis for UAJA that identified the most cost-effective unit for long-term operation and production of reclaimed water. In addition, routine water sampling produced valuable data on the quality of the reclaimed product and was utilized in public education efforts to assist in the adoption and permitting of an indirect potable reuse project.With the selection of a microfiltration unit for preliminary treatment, the second stage treatment will be identified in the Phase II Pilot Testing. By comparing nanofiltration and reverse osmosis membranes from similar manufacturing processes, the pilot testing will verify if the method of softening by nanofiltration is acceptable and provides a stable pathogen barrier as compared to reverse osmosis. The Phase II Pilot Testing will include six months of operational analysis for pressure, flux, total dissolved solids reduction, and total organic carbon (TOC) removal to ascertain the most cost-effective treatment scheme that provides the minimum level of safety desired.This presentation will be a summation of the results of the operability and water quality data collected from the operation of the pilot plants, the present worth analysis of the operation of the various microfiltration, ultrafiltration, nanofiltration, and reverse osmosis units, and recommendations for the design and implementation of a full-scale facility to be located at UAJA.