AIR WATER FOOD MULTI POINT INTERVENTION STRATEGY
TECHNOLOGY OVERVIEW • UV • Ozone • AOP • PHI
Know you’re ABC’s • UV-A, long-wave ultraviolet light in the 380 to 315 nm range • UV-B, medium-wave ultraviolet light in the 315 to 280 nm range • UV-C, short-wave ultraviolet light in the 280 to 100 nm range
UV-A • 98.7% of all UV passing through the atmosphere from sun is in the A region. • Both natural “Sun Tan” and artificial tanning lamps. Least harmful UV (…wrinkles). • Bug Zapper attractant (~365 nm). • Photocatalytic effect (very strong at 380nm)
UV-B • Also passes through atmosphere (very small amount…except when ozone holes occur). • Causes sunburn to the skin and can damage the eyes with over exposure. • Produces Vitamin D in the skin. • Too little exposure bad, to much also bad. • Photocatalytic effect (~280-300 nm).
UV-C • 100% absorbed via atmosphere. • UV-C has highest energy of A,B, and C. • Quickly causes sunburn to the skin and can damage the eyes (flash burns). • Germicidal wavelengths (254nm) • Ozone producing wavelengths (185nm) • Strong Photocatalytic effect (can actually prevent catalyst deactivation)
UV Sources • Sun • Low Pressure mercury lamps • Medium pressure mercury lamps • High pressure mercury lamps (metal halide lamps) • Very high pressure mercury and xenon lamps (pulsed lamps) • LED’s (emerging..not quite there)
UV-C (Commercial) • Disrupts DNA and RNA effectively “sterilizing” cell. • Line of site treatment (shadowing) • Minimum energy dose is required for kills • Easily determine treatment dose (published) • Energy level + time = kill dosage (CT value)
Germicidal UV (254 nm) Effectiveness is dependent upon distance, intensity and exposure time
HVAC requires a large number to treat air • Very effective on stationary surfaces • Very good for liquid purification (if applied right) • Temperature sensitive (extremes reduce it) • Hazard due to glass and mercury • Generally very effective if applied and sized correctly
Ozone Approved for Food Use • July 1997 – Ozone receives GRAS affirmation by the FDA • Prior to July 1997 ozone was only approved for potable and bottled water • June 2001 Ozone was finally approved by FDA for food contact.
Ozone“A Household Word” • No Longer only associated with the “Ozone Layer” or Smog. • Municipal and Wastewater Treatment. • Ozonated and Carbon Filtered Drinking Water. • Becoming much more accepted by food industry.
Oxygen is O2 A molecule containing two oxygen atoms Ozone is O3 A molecule containing three oxygen atoms. Ozone Molecule Oxygen Molecule What Is Ozone? OZONE IS ACTIVATED OXYGEN
Why Use Ozone? • Safety • Disinfection • Odor Control • Oxidation • Inorganics • Organics • Turbidity / Micro flocculation
Ultraviolet Light Rays UV Light Rays from the Sun Electrostatic Discharge Lighting Bolts How is Ozone Generated?
Oxygen Molecules O2 Ozone Molecules O2 O3 O1 O2 UV Light Rays or Electric Spark O3 O1 Generation
0.01 - 0.1% by weight 0.1% = 1,000ppm No Air Pre-treatment needed 0.5 - 5.0 % by weight 5.0% = 50,000ppm Air Pre-treatment necessary Differences in UV & CD Ozone Generation UV Ozone CD Ozone
Ozone Generation Technologies • Ultraviolet Light Ozone Generation • Typically ideal for air treatment applications, especially due to low mass transfer requirements. • Require no air preparation. • Low maintenance and operating costs. • Not cost effective at single pass water treatment or other very large demand systems. • Low capital cost.
Ozone Generation Technologies • Corona Discharge Ozone Generation • Ideal for fluid treatment applications or very large air systems. • Requires air preparation. • RGF only sells with oxygen systems. • Higher maintenance and operating costs. • Very effective at single pass water treatment. • High capital cost (especially for small units).
Common Oxidants 1 - Fluorine (F-) 2 - Hydroxyl Radical (OHO)* 3 - Ozone (O3)* 4 - Chlorine (Cl-) 5 - Bromide (Br-) 6 - Hydrogen Peroxide (H2O2)* 7 - Oxygen (O2)* * - Friendly Oxidizers
Advantage of “Friendly” Oxidizers • Reverts to O2, CO2 and H20 After Use • Does not leave residue (or add to TDS) • Respond Faster to Organics • Can be generated on Site • Increases Oxygen Content (for fluid applications)
What is AOP? • AOP typically refers to Advanced Oxidation Process. • In short, Advanced Oxidation is creating more powerful oxidizers from less powerful components via some external energy (typically UV…but not always!) • Products of AOP reactions are also sometimes referred to as reactive oxygen species (or ROS).
Common components used in AOP reactions include Water, Oxygen, Hydrogen Peroxide, Ozone, Chlorine Dioxide, UV light and photo catalytic surfaces. • There are multitude of reactions and pathways to produce advanced oxidation products.
Typical AOP/ROH products • OHo Hydroxyl Radical • O2- Super Oxide Ions • HO2 Hydroperoxides (includes H202) • Ozonide Ions O3-
PHOTO CATALYST AOP’s Energy: UV/other H2O2, O3 (Always exceptions: using ClO2, Fenton's reaction, Sonalysis, you can also get AOP’s)
Benefits of AOP’s • AOP reacts up to 40 times faster than ozone alone (Note that ozone reacts 3000 times faster than chlorine). • Attacks virtually all organic compounds. • Abstracts hydrogen from contaminants to form water. • Provides a redundancy of oxidizers.
The most powerful AOP product produced is the OHo (hydroxyl radical). • This reactant is 2nd only to Fluorine in reactivity • Very short lived • Is key benefit in forming other AOP compounds, especially important for production of hydroperoxides (disassociation of water) including formation of hydrogen peroxide.
PCO’s • Photocatalytic Oxidation Reactor • Uses UV light striking a catalytic bed • Creates reactive “holes” on catalyst surface • In turn producing AOP’s • Typically targeted to VOC reduction
Usually air only (always exceptions!). • Treats only the contaminants that are brought to it. • Reactions take place on the surface of catalytic bed. • The higher the surface area, and the more UV energy that reaches it, the more efficient.
As surface area of the catalytic bed increases, limitations due occur (UV shadowing). • Retention times to treat VOC’s are applicable. • Very effective when applied properly. • Can be costly
TYPICAL PCO Flow UV Source Catalyst Structure (Honeycomb, etc..,)
AO REACTOR • Usually liquid only (again, always exceptions). • Reactant is mixed with fluid stream before entering reactor (H202, O3). • Fluid with reactants enter UV reactor (basically a UV sterilizer on steroids).
Here the photocatalytic reactions occur (producing AOP’s). • Typically treats only the contaminants brought inside the reactor chamber (very targeted such as MTBE). • Can be very effective if sized correctly • Also expensive due to fluid handling and requirement for H202 and / or O3 addition
H2O2 O3 UV TYPICAL AO REACTOR
PHOTOHYDROIONIZATION Hydrogen based oxidizers created by exposing activated oxygen molecules to a hydrated catalyst containing four unique metals and 100-380 nm UV light(Photon Energy): Hydro-peroxides Hydroxides Super Oxide Ions Ozonide Ions
Photohydroionization is the creation of hydro peroxides from a reaction that takes place between the UV light, air, and the catalyst. These hydro peroxides or “friendly oxidizers” are very effective in breaking down both airborne and surface borne microbes. The High Humidity of most Food Plants benefits these reactions.
PHI Cell • Broad spectrum lamp • Quad-metallic hydrophilic coating • PPC sleeve
PHI Cell Hydrated Coating Broad spectrum UV lamp PPC Sleeve Quad-metallic Hydrophilic coating Optimal surface area
The Lamp Broad Spectrum High Efficiency 100-380 nm Long Life Coating
PPC The Protection • Breakage Containment • Non-Polar • Insulating • Wash Down Compatible
Hydrated Quad-metallic Catalytic Coating Rhodium, Titanium, Silver, Copper, Hydrating Agent • The Quad-metallic coating: • has particular affinities, • breaks bonds, • releases electrons, • holds and releases atoms, • steals other electrons. • absorbs water vapor • It changes everything but itself remains unchanged. It is a “Catalytic” process.
Quad-metallic Hydrophilic Coating “Hydrophilic” means that it attracts water, (H2O from the air) This creates an abundance of hydrogen and oxygen on the coating
Quad-metallic Hydrophilic Coating Titanium Different catalysts do different things! Titanium dioxide (TiO2) is a multifaceted compound. It's the stuff that makes toothpaste white and paint opaque. TiO2 is also a potent photocatalyst that can break down almost any organic compound.
Quad-metallic Hydrophilic Coating Silver Different catalysts do different things! Silver speeds up titanium reactions Vol. 05, INTERNATIONAL JOURNAL OF PHOTOENERGY, 2003 Enhanced activity of silver modified thin film TiO2 photocatalysts This silver doped photocatalyst decomposes the pollutant 3-times faster than the un-doped TiO2. The amount of silver alters the photocatalytic system It was postulated that silver enhanced the reduction potential of TiO2, … It was found that … the reduction potential of the photocatalytic system can be altered by varying the amount of silver doped onto the TiO2.