Download presentation
Presentation is loading. Please wait.
1
GMU Chemistry & Biochemistry PCBs and PAHs in the Anacostia River: Sampling, Concentrations and Transport in 2004-2005 Gregory D. Foster & Phillip R. McEachern Department of Chemistry & Biochemistry George Mason University Fairfax, VA
2
GMU Chemistry & Biochemistry Comparison of tPCB concentrations in sediments Highest levels occur in Anacostia River Baltimore Harbor Data compiled by J Baker (CBL)
3
GMU Chemistry & Biochemistry Study Objectives Develop automated sampling techniques to accurately measure concentrations of PCBs and PAHs in the Anacostia River and refine annual load estimates Identify mode of PCB/PAH transport in AR and develop correlations with hydrology
4
GMU Chemistry & Biochemistry 1 2 USGS Gauging Stations 1. NE Branch sfc ar: 186 km 2 Q avg :1.2x10 8 m 3 /y 2. NW Branch sfc ar: 126 km 2 Q avg :7.0X10 7 m 3 /y Watershed is ~50% urban land use ~80% urbanized in lower portion
5
GMU Chemistry & Biochemistry PCB Geochemistry: Dissolved and Particle Phases Geosolids: Alumino- silicate clay particles in water (TSM) PCBs are concentrated in geosolids through sorption Sorbed PCB (C p ng/L) Dissolved PCB (C w ng/L)
6
GMU Chemistry & Biochemistry
7
GMU Chemistry & Biochemistry Time, min Response GC-ECD Chromatogram of PCBs 56 single component peaks (HP-1, 30 m) 16 multiple component (2+) peaks 88 congeners in 72 peaks Congener No. (e.g., 119) tPCBs = sum of mass Homologue groups LOD ~0.1 ng/L
8
GMU Chemistry & Biochemistry Fluorene Phenanthrene Anthracene Fluoranathene Pyrene Benz(a)anthracene Chrysene Benzo(b)fluoranthene Benzo(k)fluoranthene Benzo(a)pyrene Indeno(cd)pyrene Benzo(ghi)perylene Dibenz(ah)anthracene Time Intensity GC/MS TIC Chromatogram Anacostia River Sediments Foster et al. (2000) Appl Geochem, 15,901 16 Priority Pollutant PAHs LOD ~ 0.5 ng/L
9
GMU Chemistry & Biochemistry Automated River Sampling
10
GMU Chemistry & Biochemistry NE Branch of the Anacostia River How do you sample a river?
11
GMU Chemistry & Biochemistry
12
GMU Chemistry & Biochemistry River sampling was initiated when rain gauge >0.15-0.25 in/hr
13
GMU Chemistry & Biochemistry
14
GMU Chemistry & Biochemistry
15
GMU Chemistry & Biochemistry
16
GMU Chemistry & Biochemistry Examples of Sampled Hydrographs
17
GMU Chemistry & Biochemistry H o: samplers equal (TSM) p>0.05 (accept) paired t test TSM: Fultz v. Isco Sampling NE Branch
18
GMU Chemistry & Biochemistry TSM: Fultz v. Isco Sampling NW Branch NA H o: samplers equal (TSM) p>0.05 (accept) paired t test
19
GMU Chemistry & Biochemistry H o: samplers equal (D+P) p>0.05 (accept) paired t test PCBs: Fultz v. Isco Sampling - D+P NE Branch
20
GMU Chemistry & Biochemistry PCBs: Fultz v. Isco Sampling - D+P NW Branch H o: samplers equal (D+P) p>0.05 (accept) paired t test
21
GMU Chemistry & Biochemistry PAHs: Fultz v. Isco Sampling - D+P NE Branch H o: samplers equal (D+P) p>0.05 (accept) paired t test
22
GMU Chemistry & Biochemistry H o: samplers equal (part) p>0.05 (accept) paired t test PAHs: Fultz v. Isco Sampling - D+P NW Branch
23
GMU Chemistry & Biochemistry PCBs & PAHs in Anacostia River Water NE & NW Branches
24
GMU Chemistry & Biochemistry Summary of tPCB Concentrations H o : base and storm flow [tPCBs] are equal p<0.05 (reject) Median Concentrations range (min-max)
25
GMU Chemistry & Biochemistry NE Br Base- and Storm Flow tPCBs
26
GMU Chemistry & Biochemistry NW tPCBs
27
GMU Chemistry & Biochemistry 61% (54) of PCB congeners detected in >80% of NE samples
28
GMU Chemistry & Biochemistry >85% of tPCB Mass Associated 54 Major Congeners
29
GMU Chemistry & Biochemistry PCB Homologue Distribution NE Branch Dissolved: 4>5>6>3>7>8>9>10 Particle: 5>4>6>7>8>3>9>10
30
GMU Chemistry & Biochemistry PCB Homologue Distribution NW Branch Dissolved: 4,5>3>6>7>8>9>10 Particle: 4>5>6>3>7>8>9>10
31
GMU Chemistry & Biochemistry Aroclor Homologue Profiles v. NE Branch % Rel Abundance
32
GMU Chemistry & Biochemistry Median [tPCBs], ng/L LBD12 Hickey11 Watts 6 Clay St.22 PEPCO23 WNY10 Diss + Part tPCB Concentrations (m/V)
33
GMU Chemistry & Biochemistry Summary of tPAH Concentrations H o : base and storm flow [tPAHs] are equal p<0.05 (reject) Median Concentrations range (min-max)
34
GMU Chemistry & Biochemistry Base Flow Storm Flow NE Br Base- and Storm Flow tPAHs
35
GMU Chemistry & Biochemistry Conclusions Particles in storm flows represent greatest PCB/PAH inputs PCBs/PAHs in dissolved phase of river water are relatively constant among flow regimes PCB/PAH hotspots are likely derived from storm flow inputs near outfalls and up small tribs in urbanized subsheds
36
GMU Chemistry & Biochemistry Acknowledgements Technical: David Velinsky, Hyun-Min Hwang, Cherie Miller, Tom Huff Students: Eldon Roberts, Robert Allen, Phil McEachern Collaborators: OWML, Appl Environ, USGS, MWCOG, MDE Sponsors: CBPO/EPA, AWTA, MWCOG, Jeffress Mem Trust, MDE
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.