Treatment of Nitrate and Mixed Nitrite/Sulfate Contaminated Waste Water

This Phase I proposal describes an innovative process to treat waste waters containing a high concentration of nitrates and mixed nitrite/sulfate, which would permit dumping to grade and/or reuse. This waste water will be produced by a second stage nitrogen tetroxide vapor scrubber system to be used in series with current sodium hydroxide/water vapor scrubbers. This new Stage II system will use a blend of sodium hydroxide and sodium sulfite in water as the scrubbing liquors and produce waste waters containing high concentrations of nitrate and mixtures of nitrates and sulfates. Mainstream's treatment system should produce an effective economical process to treat these waste waters and produce sodium hydroxide for reuse in the system and provide a detoxified by-product that would be suitable for use as a liquid fertilizer. The Phase I effort describes the development of the required chemistry and processes for neutralizing and detoxifying the waste waters and preliminary design of the associated process hardware. The Phase II effort would consist of the design, fabrication, and demonstration testing of the pilot scale process developed in Phase I. The Phase III effort would demonstrate the process operation prototype, full scale hardware, interfaced with a selected on-site operation.