PM07 Pollutant Chemistry Transport, Cycling and Fate
Exhibit Hall
8:00 AM - Monday
(PM100) Fate of nonylphenol and nonylphenol ethoxylates in biosolid/soil systems planted with crested wheatgrass.
Dettenmaier, E1, Doucette, W1, Chard, J2, Bugbee, B2, Carbone, J3, Naylor, C, 1 Utah Water Research Lab, Utah State University, Logan, Utah, USA2 Crop Physiology Lab, Utah State University, Logan, Utah, USA3 Rohm and Haas Company, Springhouse, Pennsylvania
ABSTRACT- Microcosm experiments were conducted to evaluate the fate of nonylphenol (NP) and nonylphenol ethoxylates (NPE4, NPE9) in a soil/biosolids system (99.5/0.5% w/w). Planted and unplanted microcosms were compared to determine the impact of plants (crested wheatgrass) on degradation and to evaluate the potential uptake and translocation of these compounds into above ground plant tissue. Poisoned controls were used to quantify abiotic losses. Biosolids collected from a municipal wastewater treatment plant were spiked with either NP, NPE4 or NPE9(14C-labeled and unlabeled), allowed to age for 14 days, then mixed with an agricultural soil to yield nominal concentrations of 5, 20 or 40 mg/kg. A single concentration of 14C-phenol (20 mg/kg) was also evaluated for comparison. Mineralization during the course of the study was quantified by collecting the 14CO2 produced. Plant tissue samples were analyzed for 14C at 50, 83, (shoots) and 150 days (roots and shoots) by combustion/liquid scintillation counting. Parent compound concentrations were determined at the completion of the study using supercritical fluid extraction and GC/MS or HPLC. Mineralization at the end of the study (150 days) for nonpoisoned microcosms ranged from 7.5% (NP) to 53% (phenol). There was no significant difference in mineralization between the planted and unplanted systems. Plant uptake was a function of exposure concentration and amount of water transpired. Final concentrations of 14C in the foliar tissue were similar to those in the soil but preliminary HPLC and GC/MS results suggest that most of the 14C was in the form of metabolites or unextractable rather than parent compound. Root concentrations of 14C were 3 to 4 times higher than foliar concentrations.
Key words: transpiration stream concentration factors, plant uptake, mineralization