Download or read book Continuous emissions monitoring of mercury through cavity ringdown spectroscopy written by Megan Doty Walker and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Cavity Ring Down Spectroscopy Mercury Continuous Emission Monitor written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Sensor Research & Development Corporation (SRD) has undertaken the development of a Continuous Emissions Monitor (CEM) for mercury based on the technique of Cavity Ring-Down Spectroscopy (CRD). The project involved building an instrument for the detection of trace levels of mercury in the flue gas emissions from coal-fired power plants. The project has occurred over two phases. The first phase concentrated on the development of the ringdown cavity and the actual detection of mercury. The second phase dealt with the construction and integration of the sampling system, used to carry the sample from the flue stack to the CRD cavity, into the overall CRD instrument. The project incorporated a Pulsed Alexandrite Laser (PAL) system from Light Age Incorporated as the source to produce the desired narrow band 254 nm ultra-violet (UV) radiation. This laser system was seeded with a diode laser to bring the linewidth of the output beam from about 150 GHz to less than 60 MHz for the fundamental beam. Through a variety of non-linear optics the 761 nm fundamental beam is converted into the 254 nm beam needed for mercury detection. Detection of the mercury transition was verified by the identification of the characteristic natural isotopic structure observed at lower cavity pressures. The five characteristic peaks, due to both natural isotopic abundance and hyperfine splitting, provided a unique identifier for mercury. SRD scientists were able to detect mercury in air down below 10 parts-per-trillion by volume (pptr). This value is dependent on the pressure and temperature within the CRD cavity at the time of detection. Sulfur dioxide (SO2) absorbs UV radiation in the same spectral region as mercury, which is a significant problem for most mercury detection equipment. However, SRD has not only been able to determine accurate mercury concentrations in the presence of SO2, but the CRD instrument can in fact determine the SO2 concentration as well. Detection of mercury down to the low hundreds of pptr has been accomplished in the presence of SO2 at concentration levels much higher than that found in typical flue gas emissions. SRD scientists extended the interferent testing to each individual component found in flue gas. It was found that only SO2 had a significant effect on the ring-down decay curve. Upon completion of testing the components of flue gas individually a simulated flue gas stream was used to test to the CRD instrument. The result showed accurate detection of mercury down to levels below 100 pptr in a simulated flue gas stream with the concentrations of the various components above that found in a typical untreated flue gas. A sampling system was designed and integrated into the CRD instrument to carry the sample from the flue gas stack to the CRD cavity. The sampling system was constructed so that it could be placed very close to the sampling port. SRD scientists were able to couple the UV laser light into an optical fiber, which is then sent to the sampling system. This allows the laser system to be isolated from the sampling system. Initial long-term testing revealed a couple of problems related to the stability of the output frequency of the laser system. These problems have been successfully dealt with by incorporating specific software solutions into the overall data acquisition program. The project culminated in a field test conducted at the DOE/NETL pilot plant facility in Pittsburgh, Pennsylvania. The object of the test was the evaluation of a cavity ringdown spectrometer constructed for the detection of TOTAL vapor phase mercury as a continuous emission monitor (CEM). Although there is the potential for the instrument to determine the amount of speciation between neutral elemental mercury (Hg{sup (o)}) and oxidized mercury (Hg{sup (+2)}), the initial test plan was to concentrate on the measurement of the total mercury. Another added benefit is that the measurements will report the sulfur dioxide (SO 2) concentration throughout the test. This report concludes the technical work associated with Phases I & II and the field test for the Cavity Ring-Down mercury detection project.

Download or read book A CAVITY RINGDOWN SPECTROSCOPY MERCURY CONTINUOUS EMISSION MONITOR written by and published by . This book was released on 2002 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first quarter of this project to develop a Cavity Ringdown Spectroscopy mercury continuous emission monitor involved acquisition and verification of the laser system to be used, initial cavity design, and initial software development for signal processing and data acquisition.

Download or read book A CAVITY RING DOWN SPECTROSCOPY MERCURY CONTINUOUS EMISSION MONITOR written by Christopher C. Carter, Ph. D. and published by . This book was released on 2003 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurate reporting of mercury concentration requires a detailed model that includes experimental parameters that vary, such as: pressure, temperature, concentration, absorption cross-section, and isotopic structure etc. During this quarter a theoretical model has been developed to model the 253.7 nm mercury transition. In addition, while testing the interferent species SO{sub 2}, SRD was able to determine the absorption cross-section experimentally and add this to the theoretical model. Assuming that the baseline losses are due to the mirror reflectivity and SO{sub 2}, SRD can now determine the concentrations of both mercury and SO{sub 2} from the data taken. For the CRD instrument to perform as a continuous emission monitor it will be required to monitor mercury concentrations over extended periods of time. The stability of monitoring mercury concentrations over time with the CRD apparatus was tested during the past quarter. During a test which monitored the mercury concentration every 2 seconds it was found that the standard deviation, of a signal from about 1.25 ppb Hg, was only 30 ppt. SRD continued interferent gas testing during this past quarter. This included creating a simulated flue gas composed of the gases tested individually by SRD. The detection limits for mercury, although dependent on the concentration of SO{sub 2} in the simulated gas matrix, remained well below the ppb range. It was determined that for the gases tested the only measurable changes in the baseline level occurred for SO{sub 2} and mercury. Speciation studies continued with mercury chloride (HgCl{sub 2}). This included checking for spectral speciation with both Hg and HgCl{sub 2} present in the CRD cavity. There was no observable spectral shift. Also a pyrolysis oven was incorporated into the gas delivery system both for tests with HgCl{sub 2} as well as atomization of the entire gas stream. The pyrolysis tests conducted have been inconclusive thus far.

Download or read book The Development of Cavity Ringdown Spectroscopy as a Sensitive Continuous Emission Monitor for Metals written by and published by . This book was released on 2000 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this study is to evaluate cavity ringdown spectroscopy (CRDS) as an ultrasensitive technique for trace analysis of metals. Potential applications of CRDS to meet stated Department of Energy needs include: Mercury Continuous Emission Monitor Multi-Metal Emissions Monitor Radionuclide Detector and Monitor A full description of the technique can be found in Ref. 1. Briefly, CRDS is based upon the measurement of the rate of light absorption in a closed optical cavity. PMT Cavity Mirror Sample Cavity Mirror Laser Pulse A laser pulse is injected into a stable optical cavity through one of the cavity mirrors. This light pulse is trapped between the mirror surfaces and decays exponentially over time at a rate determined by the round trip losses within the cavity. When used for trace analysis, the primary loss mechanisms governing the decay time are mirror reflectivity losses, atomic absorption from the sample, and Rayleigh scattering from air in the cavity. The decay time is given by t = d c 1- R () +als + bd (1) where d is the cavity length, R is the reflectivity of the cavity mirrors, a is the familiar Beer's Law absorption coefficient of a sample in the cavity, ls is the length of the optical path through the sample (i.e., approximately the graphite furnace length), b is the wavelength-dependent Rayleigh scattering attenuation coefficient, and c is the speed of light. Thus, variations in a caused by changes in the sample concentration are reflected in the ringdown time. As the sample concentration increases (i.e., a increases), the ringdown time decreases yielding an absolute measurement for a. With the use of suitable mirrors, it is possible to achieve thousands of passes through the sample. This results in an effective path length reaching into the kilometers and a corresponding increase in sensitivity. An additional benefit is that it is not subject to collisional 2 quenching and the branching that occur in techniques such as laser-excited atomic fluorescence (LEAFS).

Download or read book The Development of Cavity Ringdown Spectroscopy as a Toxic Metal Continuous Emission Monitor written by and published by . This book was released on 2001 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Innovative program to explore the viability of using Cavity Ringdown Spectroscopy (CRDS) for trace analysis and monitoring of remediation processes for hazardous and radioactive wastes. Cavity ringdown spectroscopy is a measurement of the rate of absorption of a sample within a closed optical cavity rather than the standard measurement of the avsorved signal strength over a given sample path. It is a technique capable of providing ultra-sensitive absorption measurements in hostile environments using commercially available easy-to-use pulsed lasers. The inherent high sensitivity stems from both the long effective sample pathlengths possible and the relaxed constraints on the accuracy of the measurement of the cavity decay time.

Download or read book The Development of Cavity Ringdown Spectroscopy as a Sensitive Continuous Emission Monitor for Metals 1998 Annual Progress Report written by and published by . This book was released on 1998 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: A critical need exists for the development of methods to monitor toxic metal concentrations in remediation system off gases in real-time at parts-per-billion levels or lower. Although several technology development projects are being pursued to meet the requirements of a multi-element metals continuous emission monitor (CEM), no current technique has met all the requirements of sensitivity and data quality. The use of cavity ringdown spectroscopy (CRS) as an ultra-sensitive analytical technique is a natural extension of previous atomic absorption spectroscopy methods. However, while CRS has rapidly gained popularity among the molecular spectroscopy community, the work reported here concerns the first efforts to apply this technique to analytical atomic spectroscopy. The objective of this project is to combine CRS with the well-established tools for sample atomization, the inductively coupled plasma (ICP) and graphite furnace (GF), to provide a viable technique for on-line, trace level continuous emission monitoring of species such as toxic metals and radionuclides with detection limits comparable to ICP-mass spectroscopy (ICP-MS). This report summarizes the authors progress in the first year of a 3-year project to develop cavity ringdown spectroscopy as a sensitive, continuous emission monitor for metals. Progress has been slightly delayed by problems associated with freeing up the matching funds necessary to purchase a new narrow-linewidth dye laser and the typical problems encountered when departments move into a new building. However, these problems have been largely solved. Their new laser system has recently arrived and additional matching funds have been obtained for the purchase of a graphite furnace. This instrument is on order and will arrive in the near future. The postdoctoral and graduate positions have been filled.

Download or read book Envimetrics ArgusHG 1000 Mercury Continuous Emission Monitor written by and published by DIANE Publishing. This book was released on with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Opsis AB HG200 Mercury Continuous Emission Monitor written by and published by DIANE Publishing. This book was released on with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Continuous Emission Monitoring written by James A. Jahnke and published by John Wiley & Sons. This book was released on 2022-05-09 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: CONTINUOUS EMISSION MONITORING The new edition of the only single-volume reference on both the regulatory and technical aspects of U.S. and international continuous emission monitoring (CEM) systems Continuous Emission Monitoring presents clear, accurate, and up-to-date information on the technical and regulatory issues that affect the design, application, and certification of CEM systems installed in power plants, cement plants, pulp and paper mills, smelters, and other stationary sources. Written by an international expert in the field, this classic reference guide covers U.S. and international CEM regulatory requirements, analytical techniques, operation and maintenance of CEM instrumentation, and more. The fully revised Third Edition remains the most comprehensive source of CEM information available, featuring three brand-new chapters on mercury monitoring, the reporting and certification of industrial greenhouse gas emissions, and the instrumentation and methods used to measure air toxic compounds including dioxins, furans, and hydrogen chloride. Thoroughly updated chapters discuss topics such as flow rate monitors, new EPA regulations, instrumentation and calibration techniques, CEM system control and data acquisition, and extractive system design. Providing environmental professionals with the knowledge of CEM systems necessary to address the present-day regulatory environment, Continuous Emission Monitoring: Discusses how CEM systems work, their advantages and limitations, and the regulatory requirements governing their operation Covers both the historical framework and technological basis of current CEM regulatory programs and standards in the United States, Canada, Europe, and Asia Offers practical guidance on sampling system selection, measurement techniques, advanced monitoring approaches, recordkeeping, and quality assurance Provides detailed technical descriptions of the technology necessary for regulatory compliance Includes new orthographic drawings to help instrument technicians and regulators with little technical background to easily understand key topics Continuous Emission Monitoring, Third Edition is an essential resource for professionals responsible for ensuring regulatory compliance, managers and technicians who purchase, operate, and maintain CEM instrumentation, regulatory personnel who write and enforce operating permits, and instructors and students in upper-level environmental engineering programs.

Download or read book Nippon Instruments Corporation MS1 DM5 Mercury Continuous Emission Monitor written by and published by DIANE Publishing. This book was released on with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of Trace Environmental Contaminants Using Cavity Ringdown Spectroscopy written by Susan Theresa Scherrer and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Environmental contamination has become a significant threat to the health and well-being of mankind as well as to the environment, prompting the establishment and implementation of stringent environmental regulations. The ability to accurately detect and quantify contaminants, such as mercury (Hg), uranium (U), and volatile organic compounds (VOCs), in real-time, in situ is of significant importance to monitoring and remediation efforts. In an effort to develop a real-time, fast-response detector that is portable, highly sensitive, and cost efficient, this research explored the feasibility of utilizing cavity ringdown spectroscopy (CRDS) in conjunction with various plasma sources and vacuum cavities to accurately detect trace quantities of contaminants. The feasibility of detecting Hg with a low power, low temperature candle-shaped microwave-induced plasma (MIP) and a copper surfatron microwave cavity with various plasma discharge tube configurations in conjunction with cavity ringdown spectroscopy (MIP-CRDS) is discussed. Detection limits were on the order of 221 ppt Hg in the vapor phase for the candle-shaped MIP and improved by a factor of 10 with the tube-shaped plasma. The ability to detect elemental Hg naturally-evaporating from contaminated soils and solutions was evaluated, and 10's of ppt were consistently obtained. Additionally, the fine structure of the Hg 253.65 nm transition was observed with each iteration of this approach. The potential of effectively generating uranium atoms and ions with a low-power, low-flow rate microwave-induced plasma was evaluated. Uranium emission spectra covering 320 - 430 nm were obtained, labeled, and compared to the available literature values. Calibration curves were generated, and the detection limits were determined to be ~0.4 ppm. The feasibility of measuring U incorporating diode laser-plasma-CRDS was explored. The preliminary studies clearly show the ability to detect U vapor with this technique and sub-ppm detection limits were obtained. A continuous wave cavity ringdown spectroscopy system (CW-CRDS) incorporating commercially available telecommunications diode lasers was constructed, and the overall sensitivity of this system was evaluated by utilizing the absorption of the asymmetric C-H stretch overtones of several VOCs, including benzene, chlorobenzene, 1,2-dichlorobenzene, toluene, and acetone. Detection limits are determined to be in the ppb's for each of the organics examined.

Download or read book Nippon Instruments Corporation Model AM2 Elemental Mercury Continuous Emission Monitor written by and published by DIANE Publishing. This book was released on with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nippon Instruments Corporation DM6 DM6P Mercury Continuous Emission Monitor written by and published by DIANE Publishing. This book was released on with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Research Opportunities for Managing the Department of Energy s Transuranic and Mixed Wastes written by National Research Council and published by National Academies Press. This book was released on 2002-11-07 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: About 155,000 cubic meters of waste contaminated with both radioactive isotopes and hazardous chemicals are stored at some 30 DOE sites, and another 450,000 cubic meters are buried. While DOE is making a concerted effort to properly dispose of this waste, the amount translates to a multi-decade effort that will require handling, characterizing, and shipping hundreds of thousands of waste containers at a total cost of billions of dollars. This report describes basic scientific research that can lead to new technologies for performing these tasks more safely and cost effectively.

Download or read book Engineering Aspects of Magnetohydrodynamics written by and published by . This book was released on 1997 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Atmospheric Traces Monitoring Using Cavity Ringdown Spectroscopy written by Bernhard Koch and published by . This book was released on 2003 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: