Aerosol Chemical Speciation Monitor (ACSM) Inter Comparison Study for Ambient Fine Aerosol Measurements in Downtown Atlanta, Georgia

Transcription

1 Aerosol Chemical Speciation Monitor (ACSM) Inter Comparison Study for Ambient Fine Aerosol Measurements in Downtown Atlanta, Georgia 13 th Annual AMS Users Meeting, 2012 S.H. Budisulistiorini 1, N.L. Ng 2, V. Verma 2, M.R. Canagaratna 3, P.L. Croteau 3, W.J. Marth 1, K. Baumann 4, E.S. Edgerton 4, S.L. Shaw 5, E.M. Knipping 6, J. Jansen 7, R.L. Tanner 7, D.R. Worsnop 3, J.T. Jayne 3, R.J. Weber 2, A. Gold 1, and J.D. Surratt 1,* 1 Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA 2 School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, USA 3 Aerodyne Research, Inc., Billerica, Massachusetts 01821, USA 4 Atmospheric Research & Analysis, Inc., Cary, North Carolina 27513, USA 5 Electric Power Research Institute, Palo Alto, California, USA 6 Electric Power Research Institute, Washington, DC, USA 7 Southern Company, 600 N. 18th St., P.O. Box 2641, Birmingham, AL Environmental Technologies, Tennessee Valley Authority, CEB 1C, P.O. Box 1010, Muscle Shoals, Alabama 35662, USA Methods Southeastern Aerosol Research and Characterization (SEARCH) Network Jefferson Street (JST) site Mixed industrial residential area ~4.2 km northwest of downtown Atlanta Suite of collocated measurements 2 research.com/studies/search/ Study period 1. Comparison of two collocated ACSMs in February Comparison of ACSM and JST adjusted continuous & 24 h filter during summer and fall 2011 (July December 2011) 3. Comparison of ACSM and Federal Reference Method (FRM) filter in, January February, April May & July

2 ACSM Settings 3 UNC GIT Sampling inlet PM 2.5 cyclone PM 2.5 cyclone Sampling line length 5 m 5 m Sampling line diameter cm OD and 0.46 cm ID stainless steel tube 1.27 cm ID for 1 m of length 0.95 cm ID for 4 m of length Sample drying 50 tube Nafion dryer (Perma Pure PD 50T 24) with 7 L min 1 of sheath air coming from dry/zero air system 200 tube nafion dryer (Perma Pure PD 200T 12 MPS) running with 0.5 L min 1 sheath air flow (under vacuum). ACSM sampling flow rate 3 L min 1 3 L min 1 IE NO3 calibration 3.79 x x RIE NH4 calibration Fitted RIE NH CE Data acquisition software ACSM_DAQ_v ACSM_DAQ_v Data analysis procedure acsm_local_1443 acsm_local_1520 UNC & GIT s ACSMs Organic & Inorganics Loadings 02/01 14:00 02/02 16:00 02/27 23:00 02/28 01:00 Power flicker 4 2

3 ACSMs Species Correlations Differences in species measurement between the two ACSMs is <10% 5 JST Measurement Methods Analyte Instrument Analytical Method Detection Limit (mg m 3 ) Frequency/Time Resolution Integrated Samples Mass FRM (Teflon, 47 mm) Gravimetry 0.2 daily SO 4 PCM1 (Teflon, 47 mm) IC day NO 3 PCM1 (Teflon, 47 mm) IC day NH 4 + PCM1 (Teflon, 47 mm) AC day Volatile NO 3 PCM1 (Nylon, 47 mm) IC day Volatile NH 4 + PCM1 (Citric acid coated cellulose, 47 mm) AC day OC PCM3 (Quartz, 37 mm) TOR day Continuous Samples Mass Sunset Continuous Carbon Oscillating microbalance min Analyzer SO 4 HSPH (modified) Reduction to SO 2 /PF min NO 3 ARA Reduction to NO/CL min NH + 4 ARA Oxidation to NO/CL min OC/TC Sunset Continuous Carbon Analyzer Combustion to CO 2 /NDIR min 6 Hansen (2003); Edgerton (2005); Edgerton (2006) 3

4 Summer 2011: ACSM vs. Filter Adjusted Continuous Measurements Avg. NR PM 1 is 15.7 ± 6.4 (μg m 3 ) 7 Zero/low naphthalene & off baseline Summer ACSM vs. 24 h Filter Based Measurements Summer ACSM vs. Filter Adjusted Continuous Measurements 8 JST NO 3 consist of volatile and non volatile NO 3 that were accounted from Nylon and Teflon filters Low SO 4 and high OM/OC consistent to previous observation in NYC using AMS (Sun et al.,2011) 4

5 Fall 2011: ACSM vs. Filter Adjusted Continuous Measurements Average NR PM 1 is 12.9 ± 9.8 (μg m 3 ) further investigation Off baseline 9 Fall ACSM vs. 24 h Filter Based Measurements Fall ACSM vs. Filter Adjusted Continuous Measurements further investigation 10 JST NO 3 consist of volatile and non volatile NO 3 that were accounted from Nylon and Teflon filters Low SO 4 and high OM/OC consistent to previous observation in NYC using AMS (Sun et al., 2011) 5

6 Winter 2011: ACSM vs. FRM Filters Measurements Difference between real time NR PM 1 and FRM PM 1 measurements is ~27% 11 Avg. NR PM1 = 6.8 ± 7.4 (μg m 3 ) Avg. FRM PM1 = 6.7 ± 4.4 (μg m 3 ) Avg. FRM PM2.5 = 7.5 ± 4.9 (μg m 3 ) Spring 2012: ACSM vs. FRM Filters Measurements Difference between real time NR PM 1 and FRM PM 1 method measurements is ~20% 12 Avg. NR PM1 = 9.9 ± 3.8 (μg m 3 ) Avg. FRM PM1 = 8.6 ± 2.7 (μg m 3 ) Avg. FRM PM2.5 = 9.7 ± 3.0 (μg m 3 ) 6

7 Summer 2012: ACSM vs. FRM Filters Measurements Difference between real time NR PM 1 and FRM PM 1 method measurements is <5% 13 Avg. NR PM1 = 8.3 ± 2.8 (μg m 3 ) Avg. FRM PM1 = 8.7 ± 2.6 (μg m 3 ) Avg. FRM PM2.5 = 10.4 ± 3.0 (μg m 3 ) Summary table for ACSM vs. JST and FRM Slope JST 24 h Filter JST Filter Adj. Continuous Sum 11 Fall 11 Sum 11 Fall 11 Org 2.77 a 2.90 a 2.96 a 3.04 a SO NO NH Cl 0.27 b 0.52 b NR PM c 1.36 c 1.14 c 1.44 c FRM PM 1 FRM PM 2.5 Win 11 Spr 12 Sum 12 Win 11 Spr 12 Sum 12 NR PM

8 Species Relative Contribution to NR PM 1 Overall ACSM measured: Higher OM than estimated OM by JST filter based & filter adjusted continuous data Lower SO 4 in both seasons Higher NO 3 in both seasons 15 Different measurement techniques introduce different uncertainties in the measurement. Both ACSM and JST applied correction factors Different calibration methods: ACSM was calibrated using standard NH 4 NO 3 aerosol. Particle measurements at JST were calibrated using standard gases. Summary 1. Species measurements by two ACSMs are highly correlated with variation on of <10%. 2. Comparison of ACSM speciated measurement and the existing particle measurements methods show that ACSM measured higher OM Real time measurement prevent loss of semi volatile compounds from sampled aerosol. ACSM SO 4 was lower which is consistent to AMS technique ACSM measured higher NO 3 species Over correction of NO 3 as semi volatile increases during colder period; the CE might have changed as well. Large organic and nitrate components led to high total NR PM Total PM 1 mass comparison between ACSM and FRM method shows a high correlation, with differences vary from 5% up to 27% 16 8

9 Acknowledgements University of North Carolina at Chapel Hill Dr. Jason Surratt (PhD Advisor) Dr. Avram Gold Dr. Zhenfa Zhang Wendy Marth Georgia Institute of Technology Dr. Vishal Verma Dr. Nga L. Ng Dr. Rodney J. Weber Funding Electric Power Research Institute (EPRI) Dr. Stephanie Shaw Dr. Eladio Knipping Aerodyne Research, Inc. Dr. John Jayne Dr. Doug Worsnop Dr. Manjula Canagaratna Dr. Philip Croteau Atmospheric Research & Analysis, Inc. (ARA) Dr. Karsten Baumann Eric Edgerton 17 Additional Slides 18 9

10 Operational & Maintenance Issues (1) Instrument Issues Electronic Signal Off Baseline 19 Problem with RIE NH 4 September calibration August calibration 10

11 Signals of m/z 15,16,17,18,28 09/05/ /10/2012 Diff Open Operational & Maintenance Issues (2) Factory Condition (June 15, 2011) October 1, 2012 Faraday Signal = 5.4e 12 SEM Signal = ~1.0e 07 Faraday Signal = 1.8e 12 SEM Signal = ~0.8e 07 Gain ~20,000 cannot be used to diagnose SEM gain decay, and use Airbeam ~1.0e 07 instead 22 11