Grantee Research Project Results

2004 Progress Report: Compact Nephelometer System for On-Line Monitoring of Particulate Matter Emissions

EPA Grant Number: R831276C007
Subproject: this is subproject number 007 , established and managed by the Center Director under grant CR831276
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: UT Center for Infrastructure Modeling and Management
Center Director: Hodges, Ben R.
Title: Compact Nephelometer System for On-Line Monitoring of Particulate Matter Emissions
Investigators: Hall, Matthew J.
Institution: The University of Texas at Austin
EPA Project Officer: Aja, Hayley
Project Period: December 1, 2003 through November 30, 2004
Project Period Covered by this Report: December 1, 2003 through November 30, 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:

The objective of this research project is to design and build a fully functional prototype compact nephelometer system capable of making high time-resolution measurements of both particulate matter (PM) mass concentration and mean diameter in a variety of exhaust gas flows.

Progress Summary:

A bench-scale nephelometer has been built that uses a diode laser emitting in the near infrared as the light source. A single avalanche photodiode (APD) is mounted on a rotary translation stage and oriented so that it can collect the scattered light from the PM stream from any angle by translating the APD in a circular arc about the axis of the measurement volume. With this setup we have demonstrated the viability of the concept.

In the experiments we have conducted so far, we have used well-characterized liquid droplet streams from two different atomizers for testing, and also three different sizes of calibrated latex spheres suspended in water. The results are very encouraging based on comparisons between the experimental data and the theoretical distributions. Some discrepancies have been found for the measurements with latex spheres, however.

We have developed our own theoretical Mie scattering code for use with the nephelometer after finding discrepancies among three different available codes.

The biggest problem occurred after the graduate student research assistant on the project graduated at the end of the fall 2003 semester. The new student that the principal investigator (PI) had found for the project decided to take a different position just as the spring 2004 semester was beginning. The PI recruited a highly qualified student from Purdue University to continue the project, and he started in August 2004. This delay slowed progress, however, and caused us to request a no-cost extension for our awarded funds.

Another problem is that discrepancies were found between some measurements and the theoretical predictions. This led to a comparison of the Mie code we were using with other available codes. We discovered that three available codes did not agree with each other, leading us to write our own code. There still are some discrepancies between the data and theory that we currently are sorting out.

We also have had two laser diode failures, one that was our fault, and one that appears to be manufacturing related.

Future Activities:

Our next step is to construct a laboratory scale 5APD nephelometer with the APDs located at optimized angles. We found the five angular locations for the photodetectors that we believe will give the best resolution of PM size. These angles are 20, 32, 48, 72, and 90 degrees from the forward scattering direction.

Four new APDs were ordered and we received them toward to end of December 2004. These will be used to complete the 5APD system. A 50 kHz A/D data acquisition system, and data recording and processing PC for the 5APD system have been acquired. Throughout the rest of this year we plan to integrate all of the systems into a working prototype instrument and continue with the work on validating its performance in a variety of particulate laden flows. We will continue working with the University of Texas Office of Technology Commercialization to find applications for the instrument with interested parties.

Journal Articles:

No journal articles submitted with this report: View all 1 publications for this subproject

Supplemental Keywords:

soot, Mie scattering, coal, agglomerates, diesel, waste, ecological risk assessment, environmental engineering, hazardous waste, advanced treatment technologies, bioremediation, contaminated waste sites, groundwater contamination, petroleum contaminants, hydrocarbon,, RFA, Scientific Discipline, Air, INTERNATIONAL COOPERATION, Waste, Ecosystem Protection/Environmental Exposure & Risk, air toxics, Environmental Chemistry, Monitoring/Modeling, Environmental Monitoring, Hazardous Waste, Environmental Engineering, Engineering, Chemistry, & Physics, Hazardous, emission control strategies, hazardous waste treatment, emissions monitoring, emission control technologies, advanced treatment technologies, air pollution control, emissions, emission control, particulate matter mass, nephelometer, air pollution control technology, emissions contol engineering, air emissions, air quality, aerosol analyzers, atmospheric chemistry

Relevant Websites:

http://dept.lamar.edu/gchsrc/ Exit

Progress and Final Reports:

Original Abstract

Final

Main Center Abstract and Reports:

CR831276    UT Center for Infrastructure Modeling and Management

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R831276C001 DNAPL Source Control by Reductive Dechlorination with Fe(II)
R831276C002 Arsenic Removal and Stabilization with Synthesized Pyrite
R831276C003 A Large-Scale Experimental Investigation of the Impact of Ethanol on Groundwater Contamination
R831276C004 Visible-Light-Responsive Titania Modified with Aerogel/Ferroelectric Optical Materials for VOC Oxidation
R831276C005 Development of a Microwave-Induced On-Site Regeneration Technology for Advancing the Control of Mercury and VOC Emissions Employing Activated Carbon
R831276C006 Pollution Prevention through Functionality Tracking and Property Integration
R831276C007 Compact Nephelometer System for On-Line Monitoring of Particulate Matter Emissions
R831276C008 Effect of Pitting Corrosion Promoters on the Treatment of Waters Contaminated with a Nitroaromatic Compounds Using Integrated Reductive/Oxidative Processes
R831276C009 Linear Polymer Chain and Bioengineered Chelators for Metals Remediation
R831276C010 Treatment of Perchlorate Contaminated Water Using a Combined Biotic/Abiotic Process
R831276C011 Rapid Determination of Microbial Pathways for Pollutant Degradation
R831276C012 Simulations of the Emission, Transport, Chemistry and Deposition of Atmospheric Mercury in the Upper Gulf Coast Region
R831276C013 Reduction of Environmental Impact and Improvement of Intrinsic Security in Unsteady-state
R831276C014 Integrated Chemical Complex and Cogeneration Analysis System: Greenhouse Gas Management and Pollution Prevention Solutions
R831276C015 Improved Combustion Catalysts for NOx Emission Reduction
R831276C016 A Large-Scale Experimental Investigation of the Impact of Ethanol on Groundwater Contamination
R831276C017 Minimization of Hazardous Ion-Exchange Brine Waste by Biological Treatment of Perchlorate and Nitrate to Allow Brine Recycle
R831276C018 Integrated Chemical Complex and Cogeneration Analysis System: Greenhouse Gas Management and Pollution Prevention Solutions