Photo-catalytics, Inc.

The United States of America As Represented by the United States

Matthew A Ratcliff

Gerald D Cooper

Helena L Chum

Jeffrey G Sczechowski

Peter D Palasz

A system for decontaminating the contaminated fluid by using photocatalytic particles. The system includes a reactor tank for holding the contaminated fluid and the photocatalytic particles suspended in the contaminated fluid to form a slurry. Light irradiates the surface of the slurry, thereby activating the photocatalytic properties of the particles. The system also includes stirring blades for continuously agitating the irradiated fluid surface and for maintaining the particles in a suspended state within the fluid. The system also includes a cross flow filter for segregating the fluid (after decomposition) from the semiconductor powder. The cross flow filter is occasionally back flushed to remove any semiconductor powder that might have caked on the filter. The semiconductor powder may be recirculated back to the tank for reuse, or may be stored for future use. A series of such systems may be used to gradually decompose a chemical in the fluid. Preferably, the fluid is pretreated to remove certain metal ions which interfere with the photocatalytic process. Such pretreatment may be accomplished by dispersing semiconductor particles within the fluid, which adsorb ions or photodeposit the metal as the free metal or its insoluble oxide or hydroxide, and then removing the semiconductor particles together with the adsorbed metal ions/oxides/hydroxide/free metal from the fluid. A method of decontaminating a contaminated fluid is also disclosed.

Method of decontaminating a contaminated fluid by using photocatalytic

Apparatus for decontaminating a contaminated fluid by using photocatalytic particles. The apparatus includes a reactor tank for holding a slurry of the contaminated fluid and the photocatalytic particles ultraviolet light irradiates the surface of the slurry, thereby activating the photocatalytic properties of the particles. Stirring blades for continuously agitate the irradiated fluid surface maintaining the particles in a suspended state within the fluid. A cross flow filter is used for separating the fluid from the semiconductor powder after the decomposition reaction is ended. The cross flow filter is occasionally back flushed to remove any caked semiconductor powder. The semiconductor powder may be recirculated back to the tank for reuse, or may be stored for future use. A series of reactor tanks may be used to gradually decompose a chemical in the fluid. The fluid may be pretreated to remove certain metal ions which interfere with the photocatalytic process. Such pretreatment may be accomplished by dispersing semiconductor particles within the fluid, which particles adsorb ions or photodeposit the metal as the free metal or its insoluble oxide or hydroxide, and then removing the semiconductor particles together with the adsorbed metal ions/oxides/hydroxide/free metal from the fluid.

Apparatus for photocatalytic treatment of liquids

An ultraviolet driven photocatalytic post-treatment technique for the purification of waste water distillates, reverse osmosis permeates and spacecraft habitat atmospheric humidity condensates is described. Experimental results show that organic impurity carbon content of simulated reclamation waters at nominal 40 PPM level are reduced to, PPB using a recirculating batch reactor. The organic impurities common to reclaimed waste waters are completely oxidized employing minimum expendables (stoichiometric oxygen). This paper discusses test results and parameteric data obtained for design and fabrication of a bread-board system. The parametric testing includes UV light source evaluation, photolysis vs photocatalysis comparison, oxygen concentration dependence, temperature dependence, reactor mixing, disinfection features, photocatalyst loading, photocatalyst degradation studies and power consumption estimates. This novel post-treatment approach for waste water reclamation shows potential for integration with closed-loop life support systems.

Photocatalytic treatment of water

A photocatalytic slurry reactor is driven by solar or artificial ultraviolet illumination. A cylindrical ultraviolet lamp is suspended by an O-ring within a cylindrical reactor jacket, creating an annular region through which a photocatalytic slurry is pumped. An optional streamlined nose cone at the inlet end of the lamp reduces flow turbulence and increases flow velocity. A helical stainless steel wire wrapped about the bulb acts as a turbulence promotor to disturb the boundary layer for increased radial mixing. A three-electrode charging-arrangement may be used to regulate the charge of the solution. In another embodiment, a reactor uses a solar collection trough to focus solar rays on a C-shaped reactor jacket, the interior of which is provided with ridges or ribs to disturb the boundary layer.

Photocatalytic slurry reactor having turbulence generating means

A process for producing peracids from lactic acid-containing solutions derived from biomass processing systems comprising: adjusting the pH of the solution to about 8-9 and removing alkaline residue fractions therefrom to form a solution comprised substantially of lower aliphatic hydroxy acids; oxidizing the solution to produce volatile lower aliphatic aldehydes; removing said aldehydes as they are generated; and converting said aldehydes to peracids.

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Lakewood, CO, United States of America

Matthew A Ratcliff