Evaluation of the Semipermeable Membrane Device (SPMD) as a Passive In Situ Concentrator of Military Organic Chemicals in Water
Final rept. 15 Jul 94-15 Jul 97
DEPARTMENT OF THE INTERIOR COLUMBIA MO
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The data presented in this report demonstrate the utility of the SPMD technique for sequestering environmentally realistic concentrations of OC pesticide residues i.e., 1 ngL, 10 ngL, and 100 ngL at water temperatures ranging from I 00C to 260C. The data are indicative of concentration independent sampling rates for the 23 OC pesticides employed in this research. As predicted by both thermodynamic and kinetic considerations, the sampling rates for all 23 OC pesticides increased from l00C to 260C. For most of the 23 OC pesticides studied, a one 1 g triolein SPMD was demonstrated to passively sample over 50 L of water after 16 days exposure at 260C. The sampling rate data presented in the report permit the use of an algorithm for estimating ambient waterborne concentrations of OC pesticides from their corresponding levels in the SPMD samples. Employing this algorithm to estimate the bioavailable i.e., dissolved portion of OC pesticides present in a wide array of aquatic systems also requires the determination of the concentration of the OCs present in the sample, knowledge of the length of exposure in days and the average temperature during deployment. The accuracy of such estimations can potentially be improved by including a permeation reference compounds to correct for biofouling and variations in aqueous flow rates. Such research is being planned at the ECRC.
- Hydrology, Limnology and Potamology
- Water Pollution and Control