Course: BFM 203 Water Treatment and Control

Lecture

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Microfiltration

These systems use micro filter media in which one filter is comprised of thousands of hollow polystyrene fibers. Each fiber is perforated with 1 micron holes. With 6 psi pressure, water is forced into the hollow fiber. This process never allows a greater finished water turbidity greater than .1 NTU. The coagulation and flocculation procesess prior to use of the micro filtration unit can be operated less precisely than with other systems. As long as a floc is formed, the quality of each floc particle is less important.

In the illustration below, you see a series of filter and bundle racks. The smaller illustration in the top right corner is a cross-section of a fiber bundle.

Flow and pressure to each unit is controlled individually, as shown in the image below, left. Visual air bubbles leaving with the filtered effluent (image below, right) indicate a broken or damaged filter.

Filtered effluent (filtrate) flows to the clear well for disinfection and pH adjustment when necessary.