Document G6gagDvZ5RpN5RpZq1dwNrzbq

RECYCLED o> AR226-2684 AR226-2684 The miracles o f science' Study Title ADSORPTION-DESORPTION SCREENING STUDIES OF AMMONIUM PERFLUOROOCTANOATE Author William R. Berti Report Completed May 2000 Performing Laboratory E. I. du Pont de Nemours and Company Environmental and Microbiological Sciences & Engineering Corporate Center for Engineering Research Central Research & Development Glasgow, Building 300, P.O. Box 6101 Newark, DE 19714-6101 Report No. EMSE-053-00 CORPORATE CENTER FOR ENGINEERING RESEARCH Page 1 of 16 CONTAINS CONFIDENTIAL BUSINESS INFORMATION DuPont EMSE Report No. 053-00 GENERAL INFORMATION Material Tested: Ammonium perfluorooctanoate Svnonvms/Codes: APFO, C-8, FC-143 DuPont Notebook No.: E98312 Sponsor: Robert Pinchot E. I. du Pont de Nemours and Company BARLML CRP-711/2210-B Study Initiated / Completed: September 1999 / May 2000 Page 2 of 16 CONTAINS CONFIDENTIAL BUSINESS INFORMATION DuPont EMSE Report No. 053-00 ADSORPTION-DESORPTION SCREENING STUDIES OF AMMONIUM PERFLUOROOCTANOATE SUMMARY Five of nine materials appeared to adsorb a significant amount (greater than 25% of APFO added) at one or more concentrations o f APFO. For four o f the five materials to which APFO significantly adsorbed, most o f the adsorbed APFO appeared not to desorb after 2 washings at one or more concentrations o f added APFO. Study Conducted by: Kristi Barnett Research Technician, EMS&E (date) Study Conducted by: Jack DeCarolis Staff Biologist, EMS&E (date) Study Conducted by: George Fisher Research Technician (date) Study Conducted by: Bogdan Szostek, Ph.D. Research Scientist, Haskell Lab (date) Report Prepared by: William R. Berti, Ph.D. Senior Research Biologist, EMS&E Page 3 of 16 CONTAINS CONFIDENTIAL BUSINESS INFORMATION (date) DuPont EMSE Report No. 053-00 INTRODUCTION AND PURPOSE APFO adsorption/desorption screening studies were performed on several test materials, including two clays, a washed sand, peat moss, and an agricultural soil from Delaware, USA. The adsorption/desorption screening studies were also performed using two surface soils and two sediments from the Ohio River collected in the vicinity o f the DuPont Washington Works plant near Parkersburg, West Virginia. The adsorption/desorption procedure used in this study was adapted from a method developed by the Office o f Prevention, Pesticides and Toxic Substances (OPPTS), United States Environmental Protection Agency for use in the testing o f pesticides and toxic substances, and the development o f test data (1). Our objectives were to develop an adsorption/desorption protocol and analytical procedure for APFO. As part o f this objective, we screened a variety of test materials for their APFO adsorption/desorption characteristics. MATERIALS AND METHODS Test Materials The Kaolin (KGa-2) and Montmorillonite (SAz-1) are Clay Mineral Society "Source Clays" and were obtained from the curator of the sample collection in the Department of Geology at the University o f Missouri, Columbia. Additional information on these and other Source Clays has been published (2). The Quikrete All-Purpose sand and Scotts sphagnum peat moss were purchased locally at a builders' supply store (Home Depot). The Sassafras soil is a surface (0 to 15 cm) soil collected from an agricultural field in Delaware, USA. The Garden Area soil and East Wood soil were surface soils collected from the DuPont Washington Works plant. The Upstream sediment was obtained from the bank o f the Ohio River upstream o f the DuPont Washington Works NPDES permitted outfall, and the Downstream sedment was from downstream of the outfall. The two soil and sediment sample from the vicinity Washington Works were collected in the fall of 1999. Physical and chemical properties o f the less than 2-mm size fractions o f the soils, sediments, clays, sand, and peat moss used in this study are listed in Tables 1 and 2. Except for the clays, all samples were screened through a 2-mm (1 0 mesh) stainless steel sieve in preparation for the absorption/desorption screening test. Furthermore, the sand was washed using DI water through 2 mm and 50-um stainless steel sieves. Material retained on the 50 um sieve was used in the study. The sand, soils, and sediments used in the studies were air-dried prior to use in the studies. Data calculations, however, were based on oven-dry weights o f the samples. Oven-diy weights were determined after drying a subsample o f material in an oven at 105C for a minimum o f 24 h. The pH of the sample were determined in a 1:1 test material to water. Percent organic matter was determined using the loss on ignition method. Screening Test: Adsorption Studies Page 4 of 16 CONTAINS CONFIDENTIAL BUSINESS INFORMATION DuPont EMSE Report No. 053-00 The adsorption test was performed in duplicate on each material. A blank containing 0.01M CaCl2 solution with test materials and no APFO and a single control at each APFO concentration but no material were also included. Each material was equilibrated with the aqueous phase of a solution o f the test chemical at 5.0,0.5 and 0.05 mg L *. prepared in 0.01M CaCl2 Sterile 50 mL Coming polypropylene centrifuge tubes were used as the test vessels. One part air-dried material (4.0 g) was weighed and 5 part test solution (20 mL) was decanted into a centrifuge tube, except the control tube. The centrifuge tubes were secured on an end-over-end mixer and agitated at about 30 rpm for 24 hours. Samples were centrifuged for 20 minutes using a RT6000B Sorvall centrifuge at 4000 x g and then filtered through a 0.2 pm nylon syringe filter into a new centrifuge tube. The volume o f aqueous supernatant was measured and refrigerated at about 5C until analyzed for the parent compound using an LC-MS. The blank and the control tubes were subjected to the same steps as the test systems, including filtering. Screening Test: Desorption Studies To each solid phase (pellet) was added a fresh volume o f 0.01M CaCl2 solution without the test chemical equal to that added in the adsorption test, 20 mL. The sample was mixed, centrifuged, filtered, stored, and analyses as was done in the adsorption studies. This desorption step was repeated a second time, resulting in two washings that were analyzed separately. Calculations Data calculations included: 1. The percent of APFO adsorbed, A: A = (G - Ce x Vo)/G x 100 = x/G x 100 2. The percent of APFO which is desorbed, D: D = [(Cl + C2)V - (Vo - V)Ce]/x x 100 3. The percent o f APFO which is not desorbed, R: R = [G - (Ce + C l + C2)V]/x x 100 4. The adsorption coefficient, K': K' = (x/m)/Ce 5. The adsorption coefficient calculated as a function o f the organic carbon content o f the test material, K'oc: K'oc = K (100/percent organic carbon) Where: 1. m = dry weight o f soil employed (g) 2. Ce = concentration of APFO remaining in solution (V) in the adsorption step (pg L' ) 3. Cl = concentration o f APFO in solution in the first wash (pg L'1) 4. C2 = concentration of APFO in solution in the second wash (pg L'1) 5. Vo = original volume of solution employed (mL) 6. V = volume of solution obtained after the adsorption step (mL) Page 5 of 16 CONTAINS CONFIDENTIAL BUSINESS INFORMATION DuPont EMSE Report No. 053-00 7. G = quantity o f material recovered from the soilless control (pg) RESULTS AND DISCUSSION O f the nine materials tested, five o f them (peat moss, Upstream sediment, East Wood soil, Garden Area soil, and Kaolin Clay) exhibited significant adsorption (greater than 25% o f APFO added) at one or more o f the added concentrations o f APFO. Peat moss alone, however, adsorbed a significant amount at all three concentrations o f added APFO; 50, 500, and 5,000 pg APFO/L. Kaolin clay adsorbed a significant amount o f APFO at 500 and 5,000 pg APFO/L. The Garden Area soil collected at Washington Works also adsorbed significant amounts o f APFO at 500 pg APFO/L. Upstream sediments from the Ohio River and East Wood soil adsorbed a significant amount o f APFO at 50 pg APFO/L only. Sand, Montmorillonite clay, Downstream sediment, and Sassafras soil did not adsorb a significant amount o f APFO at any concentration of the added APFO. Once adsorbed on peat moss, most o f the APFO (>76%) did not desorb after two washings with a solution o f 0.01M CaCl2. For the Kaolin clay, most the APFO adsorbed when added at 5,000 pg APFO/L desorbed with washing (>60%). At APFO added at 500 pg APFO/L, however, an average o f 98% did not desorb from the Kaolin clay after two washings. The East Wood soil, which adsorbed 46% o f the APFO added at 50 pg APFO/L desorbed only about 2%. For the Garden Area soil 57% o f the APFO desorbed when adsorbed from the 500 pg APFO/L solution. No measurable desorption of APFO from the Upstream sediment after two washings was observed when the APFO was added at 50 pg APFO/L. Page 6 of 16 CONTAINS CONFIDENTIAL BUSINESS INFORMATION DuPont EMSE Report No. 053-00 ADSORPTION-DESORPTION SCREENING STUDIES OF AMMONIUM PERFLUOROOCTANOATE TABLE 1. Physical properties of test materials. Test material Moisture contenti % Test Material Dry Wt., Sand Silt Clay in %%% Sand Peat moss Kaolin clay Montmorillonite Sassafrass soil 0.24 47 0.78 7.4 1.4 4.0 100 0 0 2.1 ND ND ND 4.0 0 0 100 3.7 0 0 100 3.9 71 19 10 Organic M atter % ND ND ND ND 1 Organic Carbon$ % ND ND ND ND 0.58 East Wood soil Garden Area soil Upstream sediment Downstream sediment 14 9.4 13 9.0 3.5 45 40 15 1.6 3.7 37 42 21 2.9 3.5 59 30 11 1.5 3.7 69 21 10 0.6 0.93 1.68 0.87 0.35 f Based on drying at 105C for a minimum of 24 h. t Estimated from percent organic matter. ND is not determined. Page 7 of 16 CONTAINS CONFIDENTIAL BUSINESS INFORMATION DuPont EMSE Report No. 053-00 TABLE 2. Chemical properties of test materials. Test material pHf CECt Exchangea ble cations, meq/10( ______ meq/1OOg Ca Mg Na K H Sand 6.6 ND1 ND ND ND ND ND Peat moss 3.7 ND ND ND ND ND ND Kaolin clay 3.8 3.3 ND ND ND ND ND Montmorillonite 7.6 120 ND ND ND ND ND Sassafrass soil 6.3 2.8 2.10 0.51 0.01 0.21 0.00 East Wood soil Garden Area soil Upstream sediment Downstream sediment 5.6 4.7 7.1 6.9 10 4.19 0.61 0.04 0.15 5.01 17.2 5.85 1.15 0.01 0.18 10.01 7.4 6.08 0.86 0.27 0.15 0.04 5.9 4.54 1.09 0.20 0.09 0.00 f 1:1 test material to water. X Cation Exchange Capacity. Exchangeable cations in milliequivalents/100 g test material determined by a modified ammonium acetate method, f ND is not determined. Page 8 of 16 CONTAINS CONFIDENTIAL BUSINESS INFORMATION DuPont EMSE Report No. 053-00 TABLE 3. Absorption/desorption screening test data. Test material Nominal APFO Original solution concentration volume, Vo Volume of solution after APFO in solution adsorption step, after adsorption step, APFO in first APFO in second V Ce wash, C l wash, C2 m L '1 mL mL m l'1 m i ' 1____ m l 4_____ Sand 0.00 20.0 0.05 20.0 0.5 20.0 5 20.0 18.0 2.79E+01 ND ND 18.0 1.39E+02 ND ND 18.0 4.98E+02 ND ND 18.0 3.80E+03 ND ND Peat moss 0.00 0.05 0.5 5 20.0 20.0 20.0 20.0 18.0 4.00E+01 0.00E+00 0.00E+00 18.0 7.98E+00 0.00E+00 0.00E+00 18.0 6.55E+01 4.07E+01 2.62E+01 18.0 9.62E+02 5.87E+02 3.37E+02 Kaolin clay 0.00 0.05 0.5 5 20.0 20.0 20.0 20.0 18.0 1.65E+00 0.00E+00 0.00E+00 18.0 3.83E+01 NA NA 18.0 3.27E+02 3.31E+01 7.15E+00 18.0 3.02E+03 4.52E+02 3.82E+02 Montmorillonite 0.00 0.05 0.5 5 20.0 20.0 20.0 20.0 18.0 4.45E+01 0.00E+00 0.00E+00 18.0 4.68E+01 ND ND 18.0 3.80E+02 6.25E+01 8.00E+00 18.0 3.69E+03 ND ND Page 9 of 16 CONTAINS CONFIDENTIAL BUSINESS INFORMATION DuPont EMSE Report No. 053-00 TABLE 3 (cont'd) Test material Volume of Nominal solution after AFFO Original solution adsorption step, concentration volume, Vo V URL-1 mL mL APFO in solution after adsorption step, Ce L'1 APFO in first APFO in second wash, C l wash, C2 1*8 L '1 UgL"____________ Sassafrass soil 0.00 0.05 0.5 5 20.0 20.0 20.0 20.0 18.0 0.00E+00 ND ND 18.0 4.33E+01 ND ND 18.0 4.35E+02 ND ND 18.0 3.63E+03 ND ND East Wood soil ' 0.00 0.05 0.5 5 20.0 20.0 20.0 20.0 18.0 7.50E-02 0.00E+00 0.00E+00 18.0 1.18E+01 1.63E+00 0.00E+00 17.8 3.98E+02 7.53E+01 1.98E+01 18.0 4.78E+03 7.44E+02 1.43E+02 Garden Area soil Upstream sediment 0.00 0.05 0.5 5 0 50 500 5000 20.0 18.0 20.0 18.0 20.0 18.5 20.0 17.0 -..r- 20.0 ,a ,l8.0 20.0 " ` IfcO 20.0 115 20.0 18.0 1.15E+01 2.57E+01 2.76E+02 3.68E+03 0.00E+00 1.59E+01 4.12E+02 4.36E+03 6.93E+00 1.24E+01 1.19E+02 1.09E+03 0.00E+00 8.50E-01 7.11E+01 7.71E+02 2.60E+00 3.50E+00 5.03E+01 3.79E+02 0.00E+00 0.00E+00 2.10E+01 1.79E+02 Page 10 of 16 CONTAINS CONFIDENTIAL BUSINESS INFORMATION DuPont EMSE Report No. 053-00 TABLE 3 (cont'd) Test material Volume of Nominal solution after APFO Original solution adsorption step, concentration volume, Vo V m rl mL mL APFO in solution after adsorption step, Ce M l'1 APFO in first APFO in second wash, C l wash, C2 ___ mUl____ M l - _____ Downstream sediment 0 50 500 5000 20.0 20.0 20.0 20.0 18.5 0.00E+00 0.00E+00 0.00E+00 18.0 1.99E+01 0.00E+00 0.0OE+00 18.0 4.58E+02 4.63E+01 9.83E+00 17.8 5.54E+03 5.72E+02 6.64E+01 Sassafrass soil 0.00 0.05 0.5 5 20.0 20.0 20.0 20.0 18.5 0.00E+00 0.00E+00 0.00E+00 18.5 2.04E+01 4.50E-01 0.00E+00 19.0 4.94E+02 5.32E+01 1.10E+01 16.3 5.25E+03 8.40E+02 9.64E+01 Page 11 of 16 CONTAINS CONFIDENTIAL BUSINESS INFORMATION DuPont EMSE Report No. 053-00 TABLE 4. Adsorption/desorption screening test calculations. Test material Adsorption APFO Adsorbed coefficient as a Nominal recovered from Material material Adsorbed Adsorption function of APFO the soilless Adsorbed, desorbed, material not coefficient, organic carbon, concentration control, G X x/m or Cs A D desorbed, R K' K'oc FF m Mg Mg/g % % % Sand 0.00 0 -5.57E-01 -1.40E-01 0 ND ND -5.01E-03 NDf 0.05 0.896 -1.88E+00 -4.71E-01 -210 ND ND -2.93E-03 ND 0.5 9.99 3.50E-02 8.77E-03 0 ND ND 2.36E-05 ND 5 83 6.96E+00 1.55E+00 7 ND ND 4.04E-04 ND Peat moss 0.00 0 -7.99E-01 -3.77E-01 #VALUE! #VALUE! #VALUE! #VALUE! ND 0.05 0.896 7.37E-01 3.47E-01 82 -2 102 4.36E-02 ND 0.5 9.99 8.68E+00 4.09E+00 87 12 88 6.91E-02 ND 5 83 6.38E+01 3.01E+01 77 23 77 3.28E-02 ND Kaolin Clay 0.00 0 -3.30E-02 -8.31E-03 #VALUE! 0 #VALUE! #VALUE! ND 0.05 0.896 1.30E-01 3.26E-02 15 ND #VALUE! 8.61E-04 ND 0.5 9.99 3.45E+00 8.68E-01 35 2 98 2.71E-03 ND 5 83 2.26E+01 5.70E+00 27 61 39 1.90E-03 ND Montmorillonite 0.00 0 -8.90E-01 -2.40E-01 #VALUE! #VALUE! #VALUE! #VALUE! ND 0.05 0.896 -3.90E-02 -1.05E-02 -4 #VALUE! #VALUE! -2.10E-04 ND 0.5 9.99 2.38E+00 6.44E-01 24 21 79 1.70E-03 ND 5 83 9.15E+00 2.47E+00 11 #VALUE! #VALUE! 6.75E-04 ND Sassafrass Soil 0.00 0 O.OOE+OO 0.00E+00 #VALUE! ND ND #DIV/0! #DIV/0! 0.05 0.896 2.95E-02 7.48E-03 3 ND ND 1.76E-04 3.03E-02 0.5 9.99 1.30E+00 3.28E-01 13 ND ND 7.70E-04 1.33E-01 5 83 1.04E+01 2.63E+0 12 ND ND 7.26E-04 1.25E-01 Page 12 of 16 CONTAINS CONFIDENTIAL BUSINESS INFORMATION $ H DuPont EMSE Report No. 053-00 TABLE 4 (cont'd) Test material East Wood Soil APFO recovered Nominal APFO from the soilless concentration control, G M L '1 Vg X l*g x/m or Cs Material Adsorbed, A Adsorbed material desorbed, D Adsorbed material not desorbed,R Adsorption coefficient, K' Adsorption coefficient as a function of organic carbon, K'oc Vg/g % % % 0.00 0 -1.50E-03 -4.26E-04 #DIV/0! #DIV/0! #DIV/0! #DIV/0! #DIV/0! 0.05 0.422 1.86E-01 6.35E-02 46 2 87 5.39E-03 5.81E-01 0.5 10.1 2.14E+00 7.93E-01 19 29 39 2.00E-03 2.15E-01 5 96.8 1.17E+00 1.12E+00 -6 162 -315 2.34E-04 2.52E-02 Garden Area Soil Upstream Sediment 0.00 0.05 0.5 5 0 50 500 . 5000 0 0.422 10.1 96.8 0 0.422 10.1 96.8 -2.31E-01 -9.15E-02 4.58E+00 2.32E+01 -6.30E-02 -7.15E-03 1.30E+00 7.50E+00 #DIV/0! -18 44 18 -64 -2142 57 51 164 -5.47E-03 2726 -2.70E-04 34 4.72E-03 9 2.04E-03 0.00E+00 1.05E-01 1.86E+00 9.52E+00 0.00E+00 4.25E-02 6.27E-01 3.23E+00 #VALUE! 27 16 3 #VALUE! -11 56 84 #VALUE! 90 17 -82 #VALUE! 0.00E+00 0.O0E+00 7.64E-04 -3.25E-01 -1.60E-02 2.81E-01 1.21E-01 #VALUE! 0.00E+00 0.00E+00 8.78E-02 Downstream Sediment 0 50 500 5000 0 0.422 10.1 96.8 0.00E+00 2.35E-02 9.36E-01 -1.40E+01 0.00E+00 2.11E-02 4.40E-01 -2.29E+00 #VALUE! 9 7 -23 #VALUE! -81 5 13 #VALUE! 100 34 259 #VALUE! 1.15E-03 9.75E-04 -4.11E-04 #VALUE! 3.30E-01 2.80E-01 -1.18E-01 Sassafrass Soil 0.00 0 0.00E+00 0.00E+00 #VALUE! #VALUE! #VALUE! #VALUE! #VALUE! 0.05 0.422 1.35E-02 1.46E-02 6 -44 84 7.35E-04 1.27E-01 0.5 10.1 2.17E-01 1.19E-01 0 180 -201 2.43E-04 4.19E-02 5 96.8 -8.28E+00 1.20E+00 -17 -107 -2450 2.24E-04 3.86E-02 f ND = Not determined. Page 13 of 16 CONTAINS CONFIDENTlilESuSINESS INFORMATION FIGURE 1. DuPont EMSE Report No. 053-00 i'IAl- i n Adsorption isoline of APFO onto Sand, Peat moss, Kaolin clay, Montmorillonite clay, and Sassafras soil. Page 14 of 16 CONTAINS CONFIDENTIAL BUSINESS INFORMATION x/m, ug C-8 g'1substrate DuPont EMSE Report No. 053-00 FIGURE 2: Adsorption isoline of APFO onto East Wood soil, Garden Area soil, Upstream sediment, and downstream sediments. Page 15 of 16 CONTAINS CONFIDENTIAL BUSINESS INFORMATION D uPont EMSE Report No. 053-00 Reference: 1 US EPA. 1998. Fate, transport and transformation test guidelines: OPPTS 835.1220 sediment and soil adsorption/desorption isotherm. United State Environmental Protection Agency Office of Prevention, Pesticides, and Toxic Substances. EPA712-C-98-048. January 1998 2 Olphen, H.V., and J.J. Fripiat (eds.). 1979. Data handbook for clay materials and other non metallic minerals Pergamon Press. New York 346 pp. Page 16 of 16 CONTAINS CONFIDENTIAL BUSINESS INFORMATION