Development of a DYNAJET Cavitation System for High-Rate Disinfection of Combined Sewer Overflow

Dynaflow, Inc., proposes the development of a novel hydrodynamic cavitation process for high-rate disinfection of combined sewer overflows (CSOs) that would be economical and readily applicable to both large- and small-scale systems. This process would not produce potentially hazardous by-products (as does chlorination), and would operate in the presence of suspended solids. Ultrasonically induced cavitation has been shown to remove bacteria from water as well as produce reactions in water that result in organic compound oxidation, and in general, acceleration of various chemical reactions. However, the generation of ultrasonic cavitation is energy intensive and difficult to apply at practical scales. Recent work has shown that cavitation induced by Dynaflow, Inc.¿s DYNAJETS can achieve a two order of magnitude increase in energy efficiency over ultrasonic means in oxidation of selected aqueous organic contaminants.

The Phase I research project will investigate the feasibility of using this new technology for the destruction of selected relevant microorganisms in CSOs. Operating parameters will be varied, and a scale-up design for a Phase II prototype will be developed. An assessment will be made of the efficiency and ability of the new technology to operate in the presence of suspended solids and to simultaneously remove organic compounds. Phase II will include a more extensive parameter variation, and will consider issues of optimization; implementation into practical-scale systems; and the design, fabrication, and testing of a prototype unit.

Successful completion of the proposed effort will produce a new state-of-the-art technology for the disinfection of CSO water, resulting in high-rate, high-efficiency, cost-effective systems. The immediate applications are in U.S. communities that have an estimated combined population of 40 million, with combined sewer systems. International communities represent an even larger market. The disinfection and organic contaminant oxidation for CSOs without the potential hazards of chlorine by-products, storage, and transportation will make the technology extremely attractive. Broader potential applications include simple economical means for drinking water disinfection and the removal of organic contaminants. There is a growing need for such technology throughout the world as the demand for potable water supplies increases and the available supply decreases. It also could be used in the disinfection of pharmaceutical and biotechnological wastes. The technology appears to be easily implemented at multiple scales such that it could be utilized for both large central systems, smaller systems, and individual wells.