Evaluation of passive sampling devices as potential surrogates of perchlorate or heavy metal uptake in terrestrial plants.

摘要

Anion Exchange Membrane (AEM), Chelating Anion Exchange Membrane (CAEM), NafionRTM tubing, and Strong Anion/Cation Exchange Cartridges (SAX/SCX) were evaluated as potential surrogates of Perchlorate or heavy metal uptake into soybeans grown in Ottawa sand, Nebraska soil, and Texas soil. The heavy metals tested in this study were Cadmium, Copper, and Lead. Chemical concentrations in plant tissues, NafionRTM tubing, and SAX/SCX were determined weekly. AEM/CAEM exchanged chemicals were determined hourly for 12 hours and statistically related to chemical concentrations in soybean leaves.;In this study, Perchlorate and heavy metals were taken up into soybean leaves in the experiments conducted in different soil types. AEM/CAEM also demonstrated their potential to accumulate Perchlorate and heavy metals from various types of soils. The amount of Perchlorate, Cd, and Pb accumulated on membranes increased linearly over time in sand. Perchlorate and heavy metal uptake by soybean leaves were poorly defined by linear regressions with membrane accumulation. Soil type had a significant effect on the amount of chemicals exchanged on the membrane. Significant differences were observed among the membrane experiments conducted in different soil types for all chemicals. There were no significant differences in membrane-exchanged chemicals between experiments conducted in Nebraska soil and Texas soil for perchlorate, Cd, and Pb. Significant effects of soil type were observed for heavy metal uptake in soybean. Linear regressions between chemical concentrations or log transformed chemical concentrations in water solutions within NafionRTM tubing and soil solution were significant for perchlorate, Cd, and Pb. Chemicals were not detected in the desorption solutions of SAX/SCX.;These results indicate that AEM/CAEM do not have statistically significant relationships with chemical concentrations in soybean leaves at different growth stages. NafionRTM tubing may be used as a passive sampling device for soil solution to assess bioavailability of chemicals to plants.