Ovivo Inc.

Trisep Corporation

Michael Snodgrass

Hiren Trivedi

Peter H Knappe

Combined Sewer Overflow (CSO) events require certain minimum treatment, before discharge, according to EPA regulations. However, these events are infrequent, and CSO treatment systems remain idle most of the time. Tertiary filtration is typically used to polish off the secondary treated water in order to remove suspended matter, phosphorous, etc. Tertiary systems are usually designed to handle design flows and remain active most of the time. These are two independent unit operations requiring major capital investment and operational expense. According to this invention an interchangeable system is able to switch a tertiary treatment reactor back and forth between two applications ensuring seamless operation, smooth transition and significant cost savings for treatment facilities.

Interchangeable system for overflow treatment and tertiary filtration for wastewater treatment facilities

High flow, low-pressure ultrafiltration or microfiltration spiral wound membrane cartridges are used in filtration of liquid feedstocks having high suspended solids. Applications may utilize either vacuum or pumping for transmembrane drive pressure (TMP), and gas may optionally be bubbled up through the cartridges with certain feedstocks. Water permeate flux rates as high as 90 gallons per square foot per day (gfd) can be obtained at TMPs below 5 pounds per square inch. By locating each spiral wound cartridge in its own casing and supplying liquid feedstock to an open lower end of the casing, as opposed to submerging such cartridges in a tank filled with feedstock, overall low pressure performance is greatly improved. High permeate flow can be maintained for long periods of time between shutdowns for intensive cleaning. TMP is gradually increased to maintain a substantially constant rate of permeate discharge until a target is reached, indicative of solids accumulation on the membrane surface to an undesirable extent; then backflushing is effected for a short time. Discarding the hold-up volume of feedstock in the cartridge, the backflushing fluid and dislodged solids, allows production to be promptly resumed with fresh feedstock at performance at near original levels.

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Santa Barbara, CA, United States of America

Michael Snodgrass