Improved Nutrient Removal by Upgrading Existing Wastewater Plants to Membrane Bioreactors

Across the country and Colorado in particular, wastewater treatment regulations are evolving to both protect the natural environment with stricter effluent limits and to conserving water through its reuse. When high quality effluent is required, membrane bioreactors (MBRs), such as Innovatreat's miniMBR are the treatment system of choice for a number of reasons including a physical barrier for solids removal and a high level of treatment stemming from begin able to run the bioreactors at a high concentration of mixed liquor suspended solids. Most small scale, decentralized wastewater plants employ traditional treatment technologies such as extended aeration or sequencing batch reactors, sometimes followed with tertiary filtration. If the effluent requirements change or the production of reuse quality water is desired, such that an MBR is needed, a retrofit to upgrade the facility is far more cost effective than building an entire new facility. Upgrading an existing plant to an MBR utilizing a submerged membrane cassette, while possible, can be difficult or perhaps not possible depending on the configuration of the tanks. Furthermore, this approach would likely require an extended shutdown. An attractive alternative solution, it to install Innovatreat's skidded, external tubular miniMBR system. Since the membranes and other critical equipment installed on the skid, any existing system can be upgraded to and MBR and and extended shutdown is not required. This presentation will review example flowsheets, installation sequences, and benefits of retrofitting plants with an external tubular MBR to meet strict effluent limits and/or generate reuse quality water.