Final Report: Optical Fibers Coated With Titania Membrane/UV-Generating Crystal in a Distributed-Light Photoreactor for VOC Oxidation

EPA Grant Number: R828598C744
Subproject: this is subproject number 744 , established and managed by the Center Director under grant R828598
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: Gulf Coast HSRC (Lamar)
Center Director: Ho, Tho C.
Title: Optical Fibers Coated With Titania Membrane/UV-Generating Crystal in a Distributed-Light Photoreactor for VOC Oxidation
Investigators: Li, Ku-Yen , Chen, Daniel
Institution: Lamar University
EPA Project Officer: Lasat, Mitch
Project Period: September 1, 2000 through August 31, 2004
Project Amount: Refer to main center abstract for funding details.
RFA: Gulf Coast Hazardous Substance Research Center (Lamar University) (1996) RFA Text |  Recipients Lists
Research Category: Hazardous Waste/Remediation , Targeted Research

Objective:

Volatile organic compounds (VOCs), the precursors of ground-level ozone and particulate, pose major threats to the air quality of many Texas metropolitan areas. Photocatalytic oxidation has gained much attention in air/water pollution control due to the potential to use solar energy.  Photocatalysis utilizes near-UV light to break down organic pollutants into innocuous compounds at room temperatures.  Our project deals with the destruction of VOCs using titania photocatalytic oxidation (PCO), which has the potential to become a commercialized advanced oxidation technology, especially in low concentration, low-flow rate, and non-centralized applications.  However, the low light and photon utilization efficiency hinders its widespread use. The objectives of this project are (1) to use commercially available nonlinear optical (NLO) crystals to utilize the visible light or sunlight, and (2) to test the efficiency of the fiber-optical photoreactor with model VOCs (PCE and butyraldehyde) in air. The NLO crystals such as lithium triborate (LiB3O5), barium titanate (BaTiO3) and lithium niobate (LiNbO3) have an anionic group structure capable of emitting light with double or triple the frequency of the incident light to convert the visible light into ultraviolet light to facilitate photocatalytic oxidation.   The objectives of this research are

  • to use commercially available nonlinear optical (NLO) crystals to utilize the visible light or sunlight
  • to test the efficiency of the fiber-optical photoreactor with model VOCs (PCE and butyraldehyde) in air.

Summary/Accomplishments (Outputs/Outcomes):

This research has led to the external grant: "Super-Porous Titania/NLO-Coated Fiber Optic Photoreactor for Environmental Applications" with K. Y. Li (Co-PI), ARP/ATP Texas Higher Education Coordinating Board, 003581-0019-1999, $154,000, 2000-2003.

The ferroelectric optical materials prove to be a cost-effective way of enhancing the TiO2 catalyst.  For example, barium titanate (BaTiO3) with only 0.1 wt. % can enhance VOC destruction by nearly 25%.  The technology can be easily adapted to combat indoor and ambient VOC and NOx pollutions.
In the past three years the photocatalysis laboratory at Lamar University has accomplished the following [8-11, 29]:

  • Demonstration that the fused silica optical fiber packing material is an efficient catalyst support in a photoreactor.
  • Development of the use of nonlinear optical (NLO) crystals, such as LiNbO3 (band gap 4.0 eV) and BaTiO3 (band gap 3.7-3.8 eV) as an additive to a photocatalyst.

LiNbO3 (0.25wt %) and BaTiO3 (0.1 wt %) increase the conversions of perchloroethylene (PCE) and butyraldehyde by 12-34% and by 25% in average compared to P-25 TiO2 [16]. These improvements are significant and the exact mechanisms of enhancement in photocatalysis are worth exploring.  The preliminary UV/Vis data of the NLO modified catalyst indicated a lower absorbance and a shift of plasma frequency to a lower wavelength with the additives. The XRD data also showed more scattering and other electro-optical effects.  We believe the enhancement of the optical crystal does not come from the nonlinear optical process; rather, other electric, magnetic, and optical properties may be responsible.

Modification with Optical Crystals
We also pioneered the use of nonlinear optical crystals as an additive to a photocatalyst. During the course of this project, the NLO materials BaTiO3 (band gap of 3.7-3.8 eV) and LiNbO3 (band gap 4.0 eV) were found to be beneficial when black light was used.  The optimal compositions are 0.1 wt% barium titanate (BaTiO3) and 0.25 wt% lithium niobate (LiNbO3) with the balance being TiO2.  It was found that 0.1% BaTiO3 and 99.9% TiO2 increased PCE conversion by 12% to 32% for space time 1.97-6.88 sec. and two inlet conc. 130 ppm (Fig. 1) and 40 ppm with a 4W black light. The average enhancement is approx 25%. Further, 0.25% LiNbO3 and 99.75% TiO2 increased PCE conversion by as much as 18% for space time 3.3 sec. and inlet conc. 50 ppm with a 4W black light. The maximum enhancements in butyraldehyde conversion are 34% (40ppm) and 28% (100ppm) respectively at 3.42 sec. The reaction parameters studied were space velocity, inlet concentration, humidity, and light source. Oxidation by-products were identified using a GCMS.

Initially, NLO was used with the intention of generating UV within the photocatalyst.  A typical NLO crystal has an anionic group structure that is capable of emitting light with double or triple the incident light frequency.  The process of radiating an optical field at 2T is called the second-harmonic generation (SHG). In favorable circumstances, a single frequency incident light such as a laser beam can be converted to a beam at double the frequency with an efficiency exceeding 50% [17, 18]. However, in medium or low light intensities, the SHG conversion efficiency diminishes [18].  In our experiments, barium titanate does not facilitate the photocatalytic oxidation of PCE using Degussa P-25 TiO2 by fluorescent light.  There is significant enhancement in conversion efficiency but has no effect on the reaction paths as seen from GC/MS byproduct distribution when black light is used. These results do not support the mechanism that BaTiO3 increases the conversion of PCE (with black light) by the nonlinear optical process.  We now believe these wide band gap semiconductor crystals have other interesting electric, magnetic, and optical properties [19-22] such as high transmittance, ferroelectric (electric polarization), and electro-optical properties that are responsible for the enhancement of PCO in our laboratory tests with Degussa P-25.


Figure 1.  PCE Conversion using Pure TiO2 vs. TiO2 modified with BaTiO3


Figure 2,   Comparison of Pure TiO2 and modified TiO2 UV/Vis. Spectrum Absorbance

Experiments were also conducted for different BaTiO3 concentrations in TiO2 using a fluorescent light with space time 3.62 seconds, PCE concentration 130 ppm, and catalyst loading 0.846 mg/ cm2.  Conversion of PCE with the fluorescent light actually decreases with additional barium titanate in the catalyst.  By-product identification was conducted by effluent analysis with the GC/MS. Trichloroacetylchloride (TCAC) and phosgene are the two significant by-products, same for both TiO2 and TiO2 modified with BaTiO3.

Characterization of Modified Photocatalyst
Pure TiO2, pure LiNbO3, pure BaTiO3, TiO2/BaTiO3, and TiO2/ LiNbO3 are spin-coated (Spincoater® Model P6700 Series, Specialty Coating System Inc.) on a slide and tested by a spectrophotometer (Shimadzu Corp. UV-Vis Spectrophoto-meter, model 1201) for absorption and transmittance before and after the reaction. UV/Vis. optical absorption spectra of the NLO films show that they are transparent below the band gap.  Both BaTiO3- and LiNbO3- modified TiO2‘s absorb less in the UVA/Vis. (300-550nm) compared to Degussa P-25 TiO2, Figure 2.  This indicates a higher transparency of the modified TiO2 and is consistent with the wide optical transparency range of pure BaTiO3 and LiNbO3.  We also observed a shift of transmission bottom (plasma frequency) toward a lower wavelength corresponding to a higher electron density.  Perovskites such as BaTiO3 with formula ABX3 are a common type of mineral structure and include many interesting materials such as ferroelectrics and superconductors. ABX3 type ferroelectric crystals are divided into the perovskite, ilmenite and tungsten-bronze types.  Many ferroelectrics are chemically expressed as ABO3 (BaTiO3), with an octahedron constructed by six oxygen atoms including a smaller metallic element near their center, Fig.2.  Ferroelectric materials possess spontaneous electric polarization such that the polarization can be reversed by an electric field. The displacement of the center Ti ion in BaTiO3 results in an electric polarization and a net electric dipole moment [19, 21]. The charge amount of electrical polarization moment per unit area is electrical polarization (µC/cm2).


Figure 3. Single Perovskite Crystal

In fact, pure TiO2 is opaque and highly reflective, the photons can only reach surface layers and, to a great extent, is reflected. The transparent NLO crystal serves as an internal waveguide for the UV light penetrating to the deeper layers of the catalyst and, as a result, enhancing the light utility efficiency.  The displacement of BaTiO3 ions results in a net electric dipole moment. The X-ray diffraction data also showed more scattering and other electro-optical effects. Thus, the mechanisms for NLO to benefit may be three-fold: First, NLO would contribute to PCO by transmission, i.e., as a waveguide to transmit the light energy into the inner layers. Second, it may be due to the perovskite or ferroelectric behavior (net electric dipole moment) that impedes electron-hole recombination.  Three, other electrical, magnetic, and optical properties such as electric field-induced scattering may enhance light utilization within the catalyst.

The fraction of light attenuated from the TiO2 coated optical fiber was measured by using a Fiber Optical UV-VIS Spectroscopy (S-2000, Ocean Optics).  The effect of coating thickness and appropriate lengths were determined with a redesigned apparatus allowing light transmitted only through the fibers. The length of transmission is at least 10 – 15 cm. BaTiO3/ TiO2 was also coated at the inner layer of an optical fiber when using the redesigned photoreactor for the Oriel system.  The optimum weight of the catalyst was found out to be 80 mg and the optimum composition is 0.5% BaTiO3 with a conversion of 37.8% vs. pure TiO2 (33.2%) and 1% BaTiO3 (31.5%).


Journal Articles on this Report : 2 Displayed | Download in RIS Format

Other subproject views: All 6 publications 3 publications in selected types All 3 journal articles
Other center views: All 359 publications 104 publications in selected types All 90 journal articles
Type Citation Sub Project Document Sources
Journal Article Chen DH, Ye X, Li K. Oxidation of PCE with a UV LED photocatalytic reactor. Chemical Engineering & Technology 2005;28(1):95-97. R828598 (Final)
R828598C744 (Final)
CR831276 (Final)
R831276C004 (2004)
  • Abstract: Wiley Online - Abstract
    Exit
  • Journal Article Li K, Liu SYC, Huang C, Esariyaumpai S, Chen DH. TiO2 photocatalytic oxidation of butyraldehyde, ethylbenzene and PCE in the air through concentric reactors. Journal of Advanced Oxidation Technologies 2002;5(2):227-232. R828598 (Final)
    R828598C744 (Final)
  • Abstract: Ingenta
    Exit
  • Supplemental Keywords:

    RFA, Scientific Discipline, Air, Waste, POLLUTANTS/TOXICS, air toxics, Geochemistry, Chemicals, Hazardous Waste, Ecological Risk Assessment, Ecology and Ecosystems, Hazardous, Engineering, Chemistry, & Physics, hazardous waste treatment, titania surfaces, VOCs, air pollution control, distributed light photoreactor, fiber optic photoreactors, Ethylbenzene, butyraldehyde, titania membranes, photochemical oxidation, photocatalytic oxidation, air pollution control technology, Volatile Organic Compounds (VOCs), urban environment, VOC treatment, VOC remediation, photocatalytic control technology

    Relevant Websites:

    http://HAL.LAMAR.EDU/~che_dept/photocatalysis/homepage.htm

    Progress and Final Reports:

    Original Abstract
  • 2001 Progress Report
  • 2002
  • 2003

  • Main Center Abstract and Reports:

    R828598    Gulf Coast HSRC (Lamar)

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R822721C529 Environmentally Acceptable Endpoints: Risk Based Remediation Using Bioremediation
    R822721C552 Degradative Solidification/Stabilization Technology for Chlorinated Hydrocarbons
    R822721C569 Treatment and Product Recovery: Supercritical Water Oxidation of Nylon Monomer Manufacturing Waste
    R822721C620 Colloidal Fouling of Membranes: Implications in the Treatment of Textile Dye Wastes and Water Reuse
    R822721C626 Catalytic Hydroprocessing of Chlorinated Organics
    R822721C627 The Interaction of Microbial Activity and Zero Valent Iron Permeable Barrier Technology
    R822721C630 Microbial Cometabolism of Recalcitrant Chemicals in Contaminated Air Streams
    R822721C633 Catalyst Lifetime Studies for Chlorocarbon Steam Reforming
    R822721C635 Electrokinetic/Surfactant-Enhanced Remediation of Hydrophobic Pollutants in Low Permeability Subsurface Environments
    R822721C636 Transformation Reactions of Nitroaromatic and Nitrogen Heterocyclic Compounds on Granular Activated Carbon (GAC) Surfaces: Enhancement of GAC Adsorption in Natural and Engineered Environmental Systems
    R822721C640 Environmentally Friendly Organic Synthesis in Supercritical Fluids
    R822721C645 Development and Evaluation of an Integrated Model to Facilitate Risk-Based Corrective Action at Superfund Sites
    R822721C651 Adjustable Biopolymer Chelators for Cadmium, Lead and Mercury
    R822721C653 New Electrochemically Smart Catalysts for Hazardous Waste Management and Development of Capillary Electrophoresis for Analysis of their Products
    R822721C655 Soil Sampling in South Alabama Oil Fields
    R822721C659 Subsurface Contamination Site Characterization via a Computer-Aided Visual Tool
    R822721C661 New Insoluble supports for Protein Immobilization for Use in Metalloprotein Affinity Metal Chromatography
    R822721C663 Soil Remediation with Ultra-High-Efficiency Hydrocyclones
    R822721C669 Solid Acid Catalyzed Alkylation in Supercritical Fluids
    R822721C679 Regeneration/Reactivation of Carbon Adsorbents by Radio Frequency (RF) Induction Heating
    R822721C687 Improved Halogen Resistance of Catalytic Oxidation
    R822721C696 Phytoremediation and Bioremediation of Land Contaminated By PAHs, PCBs, and TNT
    R822721C697 Fundamental and Kinetic Investigation of Sorbent Technology for Optimum Mercury Emission Control
    R822721C700 Effects of Natural and Cyclic Variations on Contaminant Fate and Transport
    R822721C703 Enhancement of DNAPL Dissolution Rates by Dechlorinating Anaerobes
    R826694C620 Colloidal Fouling of Membranes: Implications in the Treatment of Textile Dye Wastes and Water Reuse
    R826694C625 Enhanced Treatment of DNAPLs Contaminated Soils and Groundwater Using Biosurfactants: In-Situ Bioremediation
    R826694C626 Catalytic Hydroprocessing of Chlorinated Wastes
    R826694C627 The Interaction of Microbial Activity and Zero Valent Iron Permeable Barrier Technology
    R826694C629 Biofiltration of BTEX in Petroleum-Contaminated Soil Remediation Off-Gas
    R826694C630 Microbial Cometabolism of Recalcitrant Chemicals in Contaminated Air Streams
    R826694C633 Catalyst Lifetime Studies for Chlorocarbon Steam Reforming
    R826694C635 Electrokinetic/Surfactant-Enhanced Remediation of Hydrophobic Pollutants in Low Permeability Subsurface Environments
    R826694C636 Transformation Reactions of Nitroaromatic and Nitrogen Heterocyclic Compounds on Granular Activated Carbon (GAC) Surfaces: Enhancement of GAC Adsorption in Natural and Engineered Environmental Systems
    R826694C640 Environmentally Friendly Organic Synthesis in Supercritical Fluids
    R826694C645 Development and Evaluation of an Integrated Model to Facilitate Risk-Based Corrective Action at Superfund Sites
    R826694C651 Adjustable Biopolymer Chelators for Cadmium, Lead, and Mercury Remeidation
    R826694C659 Subsurface Contamination Site characterization Via a Computer-Aided Visual Tool
    R826694C661 New Insoluble supports for Protein Immobilization for Use in Metalloprotein Affinity Metal Chromatography
    R826694C669 Solid Acid Catalyzed Alkylation in Supercritical Reaction Media
    R826694C679 Regeneration and Reactivation of Carbon Adsorbents by Radio Frequency Induction Heating
    R826694C696 Phytoremediation and Bioremediation of Land Contaminated By PAHs, PCBs, and TNT
    R826694C697 Fundamental and Kinetic Investigation of Sorbent Technology for Optimum Mercury Emission Control
    R826694C700 Effects of Natural Cyclic Variations on Contaminated Fate and Transport
    R826694C703 Enhancement of DNAPL Dissolution Rates by Dechlorinating Anaerobes
    R826694C705 A Pilot Plant for Producing Mixed Ketones from Waste Biomass
    R826694C722 The Effects of an Oily-Phase on VOC Emissions from Industrial Wastewater
    R826694C724 Mercury Removal from Stack Gas by Aqueous Scrubbing
    R826694C725 Transport, Fate and Risk Implications of Environmentally Acceptable Endpoint Decisions
    R826694C731 Development and Application of a Real-Time Optical Sensor for Atmospheric Formaldehyde
    R826694C734 An Advanced System for Pollution Prevention in Chemical Complexes
    R828598C001 Field Study Abstract: A Model of Ambient Air Pollution in Southeast Texas Using Artificial Neural Network Technology
    R828598C002 Hollow Fiber Membrane Bioreactors for Treating Water and Air Streams Contaminated with Chlorinated Solvents
    R828598C003 Fugitive Emissions of Hazardous Air Pollutants from On-Site Industrial Sewers
    R828598C004 Biofiltration Technology Development
    R828598C005 A Risk-Based Decision Analysis Approach for Aquifers Contaminated with DNAPLs
    R828598C006 In-Situ Remediation for Contaminated Soils Using Prefabricated Vertical Drains
    R828598C007 Membrane Technology Selection System for the Metal Finishing Industry
    R828598C008 Sequential Environments for Enhanced Bioremediation of Chlorinated Aliphatic Hydrocarbons
    R828598C009 Waste Minimization in the Magnetic Tape Industry: Waterborne Coating Formulations for Magnetic Tape Manufacture
    R828598C010 Soil Remediation by Agglomeration with Petroleum Coke
    R828598C011 Recovery of Dilute Phosphoric Acid in Waste Streams Using Waste Gas Ammonia: The Regenerative MAP/DAP Process
    R828598C012 Stochastic Risk Assessment for Bioremediation
    R828598C013 Selective Removal of Heavy Metals from Wastewater by Chelation in Supercritical Fluids
    R828598C014 Optimization of Treatment Technologies for Detoxification of PCB Contaminated Soils
    R828598C015 Wastewater Remediation by Catalytic Wet Oxidation
    R828598C016 Permanence of Metals Containment in Solidified and Stabilized Wastes
    R828598C017 Combustion Enhancement by Radial Jet Reattachment - Low Generation of Hazardous Gases and High Thermal Efficiency
    R828598C018 A Process To Convert Industrial Biosludge and Paper Fines to Mixed Alcohol Fuels
    R828598C019 Homogeneous Catalysis in Supercritical Carbon Dioxide
    R828598C020 Ultrasonic Enhancement of the Removal of Heavy Metals
    R828598C021 The Binding Chemistry and Leaching Mechanisms of Advanced Solidification/Stabilization Systems for Hazardous Waste Management
    R828598C022 Development of an Air-Stripping and UV/H2O2 Oxidation Integrated Process To Treat a Chloro-Hydrocarbon-Contaminated Ground Water
    R828598C023 A Comparative Study of Siting Opposition in Two Counties
    R828598C024 Sonochemical Treatment of Hazardous Organic Compounds II: Process Optimization and Pathway Studies
    R828598C025 Laser Diagnostics of the Combustion Process within a Rotary Kiln Incinerator
    R828598C026 Use of Inorganic Ion Exchangers for Hazardous Waste Remediation
    R828598C027 Kaolinite Sorbent for the Removal of Heavy Metals from Incinerated Lubricating Oils
    R828598C028 Destruction of Chlorinated Hydrocarbons in Process Streams Using Catalytic Steam Reforming
    R828598C029 Integrated Process Treatment Train (Bioremediation {Aerobic/Anaerobic} and Immobilization) for Texas Soils Contaminated with Combined Hazardous Wastes
    R828598C030 Photo-Oxidation by H2O2/VisUV of Off-Gas Atmospheric Emissions from Industrial and Environmental Remediation Sources
    R828598C031 Concentrated Halide Extraction and Recovery of Lead from Soil
    R828598C032 Biodegradable Surfactant for Underground Chlorinated Solvent Remediation
    R828598C033 A Software Guidance System for Choosing Analytical Subsurface Fate and Transport Models Including a Library of Computer Solutions for the Analytical Models
    R828598C034 Hydrodynamic Modeling of Leachate Recirculating Landfill
    R828598C035 Measurement of Oxygen Transfer Rate in Soil Matrices
    R828598C036 Sorbent Technology for Multipollutant Control During Fluidized Bed Incineration
    R828598C037 Pollution Prevention by Process Modification Using On-Line Optimization
    R828598C038 Pollution Prevention by Process Modification
    R828598C039 Water Solubility and Henry's Law Constant
    R828598C040 Transferring Technical Information on Hazardous Substance Research by Publishing on the World Wide Web
    R828598C041 Stress Protein Responses to Multiple Metal Exposure in Grass Shrimp
    R828598C042 Life-Cycle Environmental Costing for Managing Pollution Prevention in the Chemical and Petroleum Refining Industries: A Cross-Border Approach
    R828598C687 Improved Halogen Resistance of Catalytic Oxidation Through Efficient Catalyst Testing
    R828598C696 Phytoremediation and Bioremediation of Land Contaminated By PAHs, PCBs, and TNT
    R828598C697 Fundamental and Kinetic Investigation of Sorbent Technology for Optimum Mercury Emission Control
    R828598C700 Effects of Natural Cyclic Variations on Contaminated Fate and Transport
    R828598C703 Enhancement of DNAPL Dissolution Rates by Dechlorinating Anaerobes
    R828598C705 A Pilot Plant for Producing Mixed Ketones from Waste Biomass
    R828598C722 The Effects of an Oily-Phase on VOC Emissions from Industrial Wastewater
    R828598C724 Mercury Removal from Stack Gas by Aqueous Scrubbing
    R828598C725 Transport, Fate and Risk Implications of Environmentally Acceptable Endpoint Decisions
    R828598C731 Development and Application of a Real Time Optical Sensor for Atmospheric Formaldehyde
    R828598C734 An Advanced System for Pollution Prevention in Chemical Complexes
    R828598C743 Field Demonstration of Ultrasound Enhancement of Permeable Treatment Walls
    R828598C744 Optical Fibers Coated With Titania Membrane/UV-Generating Crystal in a Distributed-Light Photoreactor for VOC Oxidation
    R828598C749 Characterization and Modeling of Indoor Particulate Contaminants In a Heavily Industrialized Community
    R828598C753 Adsolubilization and Photocatalysis in a Semiconducting Monolithic Reactor for Wastewater Treatment
    R828598C754 Remote Detection of Gas Emissions in Industrial Processes
    R828598C759 Searching for Optimum Composition of Phosphogypsum: Fly ash: Cement Composites for Oyster Culch Materials
    R828598C761 Development of a Phytologically-Based Biosorptive Water Treatment Process
    R828598C766 Chlorinated Solvent Impact and Remediation Strategies for the Dry Cleaning Industry
    R828598C769 Soil/Sediment Remediation by Hot Water Extraction Combined with In-Situ Wet Oxidation
    R828598C771 Fluoracrylate Polymer Supported Ligands as Catalysts for Environmentally Benign Synthesis in Supercritical Fluids
    R828598C774 The Feasibility of Electrophoretic Repair of Impoundment Leaks
    R828598C777 Surfactant Enhanced Photo-oxidation of Wastewaters
    R828598C778 Stationary Power Generation Via Solid Oxide Fuel Cells: A Response to Pollution and Global Warming
    R828598C786 Photocatalytic Recovery of Sulfur and Hydrogen From Hydrogen Sulfide
    R828598C787 Biosurfactant Produced from Used Vegetable Oil for removal of Metals From Wastewaters and Soils
    R828598C789 Genetic Engineering of Enzymatic Cyanide Clearance
    R828598C791 Characterizing the Intrinsic Remediation of MTBE at Field Sites
    R828598C799 Simultaneous Water Conservation/Recycling/Reuse and Waste Reduction in Semiconductor Manufacturing
    R828598C801 Building Defined Mixed Cultures To Biodegrade Diverse Mixtures Of Chlorinated Solvents
    R828598C802 Engineering of Nanocrystal Based Catalytic Materials for Hydroprocessing of Halogenated Organics
    R828598C807 Commercial Demonstration of Hydrogen Peroxide Injection to Control NOx Emissions from Combustion Sources
    R828598C809 Evaluating Source Grouting and ORC for Remediating MTBE Sites
    R828598C810 Application of Total Cost Assessment To Process Design In the Chemical Industry
    R828598C846 Quantitative Demonstration of Source-Zone Bioremediation in A Field-Scale Experimental Controlled Release System