Charles Sarnoski Delaware Department of Natural Resources & Environmental Control Division of Air Quality

Transcription

1 Charles Sarnoski Delaware Department of Natural Resources & Environmental Control Division of Air Quality

2 Thermal Desorption before TO-17 circa 1982

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4 Why an Interest in Air Toxics? 2003 Delaware Air Toxics Assessment Study DATAS Collect data to understand cancer and non-cancer related health impacts Area of highest concern (New Castle County / Wilmington) DATAS study used Suma canisters for VOC s DATAS also studied metals and carbonyls

5 Air Toxic Project Objectives Establish an enhanced VOC monitoring program in Delaware capable of performing fast & accurate VOC measurements in communities identified through modeling as potential hotspots. Investigate temporal and spatial variations in VOC concentrations at community level. Build time-resolved VOC data set to be used for improved model validation. Evaluate concentration changes in ambient air of specific VOCs Build community-level data set of specific hazardous air pollutants (HAPs) to accomplish health-risk assessment goals in cooperation with Delaware Department of Health and Social Services (DHSS).

6 Air Toxic Project Considerations Collect samples in conjunction with EPA VOC 1/6 schedule SUMA canisters provide 24 hr. integrated sample Collect time resolved samples using EPA Method TO- 17 Determine temporal and spatial variability. DATAS identified five compounds of interest 1,3 butadiene, Benzene, Carbon Tetrachloride, Ethyl Benzene, Toluene Concentrate on Northern New Castle County/Wilmington

7 The Journey Begins When you begin a journey of a thousand miles don t start with worn out shoes. Sarnoski circa 2008 DE purchases demo PE Clarus 550 GC/MS with ATD (made us an offer we couldn t refuse) Frequent filament failures new design for PE Calibration issues (Cal Curves & MDL s for 65 compounds) ATD intermittent operation Frequent power outages power supply into building Personnel Issues ( 3 operators between 06 07)

8 TARGET COMPOUND LIST Dichlorodifluoromethane Methyl Chloride 1,2-dichloro-1,1,2,2- tetrafluoroethane Vinyl Chloride Methyl Bromide Ethyl Chloride Trichlorofluoromethane 1,1-dichloroethene Dichloromethane 3-chloropropene 1,1,2-trichloro-1,2,2- trifluoroethane 1,1-dichloroethane Cis-1,2-dichloroethane Trichloromethane 1,2-dichloroethane 1,1,1-trichloroethane Benzene Carbon Tetrachloride 1,2-dichloropropane Trichloroethene Cis-1,3-dichloropropene Trans-1,3-dichloropropene 1,1,2-trichloroethane Toluene 1,2-dibromoethane Tetrachloroethene Chlorobenzene Ethylbenzene m,p-xylene Styrene 1,1,2,2-tetrachloroethane o-xylene 4-ethyltoluene 1,3,5-trimethylbenzene 1,2,4-trimethylbenzene m-dichlorobenzene Benzyl Chloride p-dichlorobenzene o-dichlorobenzene 1,2,4-trichlorobenzene Hexachlorobutadiene 1,3-butadiene

9 PE Clarus 550 GC/MS with ATD

10 Perkin Elmer Sorbent Tube Sampler

11 Sorbent Tubes

12 Sorbent Tube Sampler w/ Tubes

13 Sampler Housing

14 Initial Project Logistics 12-2 hour samples w/ 1 field blank collected every 6 th day at 6 sites (approximately 4 liters of sample collected per tube) 78 tubes collected per sample run Samples analyzed along with blanks and QC checks Approximately 120 minute analysis time per sample tube 47 tubes per GC/MS run 2 days to complete analysis run of 3 site **4 days to analyze 1 set of collected samples** All tubes baked before deployment (30 min./tube) 39 hrs. (6 days to analyze and prepare tubes for sampling) Develop realistic sampling schedule - anticipate obstacles

15 Sampling Concerns No temperature control (summer vs winter) Humidity Pump has rudimentary flow control Flow through sample tubes not consistent Breakthrough volume (Sample collected at approximately 35 cc/min for 2 hours, approximately 4.2 liters of sample collected per tube)

16 Analytical Concerns Sample tube purged with He carrier gas to remove water before thermal desorption. Sample loss during this process?? Sorbent based on BENZENE resin? WHAT!! Sorbent has inconsistent Benzene background (application is pushing limit of sorbent because of background) Breakthrough Volume for benzene. Technical data on sorbent not forthcoming (manufacture top secret) Sorbent tubes changed from glass to S.S. (vendor states that the S.S. tubes are better suited for application why did we start with glass?) Copious amounts of data

17 DATA Below MDL s Ambient Air Toxic concentrations are very low, sub ppb GC/MS software reports zero if peak area is below 100,000? Most results are below this 100,000 threshold GC/MS reports peak areas under 100,00o but no concentration Simple ratio method C A = ( A A /A S ) C S C A = Concentration of Analyte A A = Area of Analyte A S = Peak Area of Calibration Standard C S = Concentration of Standard Always looking for alternatives

18 Air Toxic Projects Delaware Community Air Toxics Study (CATS) Analyze for 65 compounds Delaware City Sorbent Tube Study Analyze for BTEX compounds ongoing Wilmington Sorbent Tube Study Analyze for BTEX compounds

19 Data When We See Something

20 Typical Diurnal Pattern

21 Typical Diurnal Pattern

22 Moveable Monitoring Platform

23 MMP Instrument Rack

24 Syntech BTEX Auto GC

25 Station Data System

26 BTEX Data (12/07 to 12/13)

27 BTEX Data 12/6/15

28 BTEX Data 12/13/15

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