Tennessee Valley Authority

Johnny R Gamble

Jeffrey L Boles

Laura Waneta Lackey

Kenneth E McGill

The present invention relates to novel ex situ processes for simple and economical destruction of air, water, and soil contaminants using naturally occurring microorganisms that are widely available in the environment. The processes utilize novel closed-loop recycle schemes which dramatically improve the efficiency, economics, and practicability of destruction of a wide variety of contaminants, especially VOCs and chloroethylenes, and particularly trichloroethylene (TCE). The processes may be applied on a batch or continuous basis to contaminated soil and groundwater, to contaminated effluents from a wide variety industrial operations, or to wherever such amenable contaminants are present. Certain contaminants, particularly chloroethylenes, are known to be difficult to biodegrade aerobically to non-toxic products without the employment of a primary substrate to induce cometabolic degradation. Ordinarily, practical and economical cometabolic degradation of these compounds via a primary substrate is not possible because direct metabolic degradation of the primary substrate itself competes with degradation of the target pollutants, thus rendering degradation of the target pollutants economically prohibitive. The processes of the present invention utilize novel closed-loop recycle schemes and separate primary substrate streams and contaminant streams into separate and discrete process cycles to achieve simple, practical, and economical degradation of target pollutants. Conventional wisdom indicates that these closed-loop recycle schemes should deplete the oxygen supply, causing loss of the aerobic microorganisms and process failure. However, the novel closed-loop recycle schemes of the present invention unexpectedly result in dramatically improved efficiencies and economics for degradation of a wide variety of pollutants, particularly chloroethylenes.

High-efficiency processes for destruction of contaminants

An improved process for the production of granular ammonium polyphosphate fertilizer of a nominal 11-56-0 grade resulting from the pressure ammoniation of phosphoric acid without the use of a preneutralizer and using a specially designed pipe reactor to effect coating and granulation of an anhydrous melt onto cascading granules of ammonium polyphosphate with polyphosphate contents thereof ranging from about 15 percent to 30 percent of the total P.sub.2 O.sub.5. The instant invention defines the operating parameters which allow for the practice of a process wherein there is essentially no degradation in the amount of P.sub.2 O.sub.5 values produced as polyphosphate in the melt as said melt is further processed in the remaining steps therein through the step of product recovery, i.e., we have discovered the parameters for operating a process wherein essentially no hydrolysis of the polyphosphate P.sub.2 O.sub.5 values in the melt occurs. In addition, because of the low moisture content of the melt as produced and provisions for the removal of that remaining in said melt as it is processed in the granulator, the requirement for the dryer that is normally required and used in most conventional processes is eliminated. The product is physically and chemically structured so that it is harder than similar grade granules made in accordance with the dictates and teachings of conventional processes. The product resulting from practice of the instant invention contains more polyphosphate than similar products made by ammoniation of wet-process orthophosphoric acids. The high quality product resulting from the practice of the preferred embodiments of the instant invention is dust-free, not agglomerated, and well suited for direct use in bulk blends or as starting materials for the production of high-quality suspension fertilizers.

Growing community of inventors

Florence, AL, United States of America

Johnny R Gamble