A TALE OF TWO WATERS: USING A SINGLE SET OF MEMBRANE EQUIPMENT FOR BOTH DIRECT FILTRATION AND SETTLED WATER FILTRATION

摘要

The City of Mansfield (City) Bud Ervin Water Treatment Plant (WTP) has underdone multipleexpansions over the past three decades. The Phase IV expansion was the most recent expansionand included the selection and design of a low-pressure membrane system. Phase I, II, and IIIutilized conventional treatment systems (flocculation/sedimentation followed by gravityfiltration). The membrane system was selected due to site limitations and the City’s desire tocontinue to phase the needed capacity in over time. The membrane system can be operated intwo different treatment modes: (1) settled water mode, so that water from the existingconventional facility is further treated by the membrane system or (2) direct membrane filtrationthat provided the additional capacity beyond the conventional system. The results of thecommissioning of the membrane system revealed that the difference between these two modes ofoperation was in the method of delivery of the water to the membranes.