HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Fan, Z. Articles by Larsen, G. L. Search for Related Content PubMed PubMed Citation Articles by Fan, Z. Articles by Larsen, G. L. Agricola Articles by Fan, Z. Articles by Larsen, G. L. Related Collections Batch Studies Laboratory Column Studies Coupled Flow/Transport Models

Discerning and Modeling the Fate and Transport of Testosterone in Undisturbed Soil

^a Dep. of Soil Science, North Dakota State Univ., Fargo, ND 58105
^b USDA-ARS, Animal Metabolism-Agricultural Chemicals Research, Biosciences Research Lab., Fargo, ND 58105

View larger version (21K): [in this window] [in a new window]   Fig. 1. Schematic of the models that were used to describe the fate and transport of testosterone. The convection processes and gas collection are limited only to miscible-displacement experiments.

View larger version (28K): [in this window] [in a new window]   Fig. 2. Schematic of the miscible-displacement experimental setup. Tygon tubing (6-mm i.d.) was used for all connections. In Experiment 1, the effluents from the soil column were directly collected in the fraction collector without running through the stainless steel cylinder and trapping 14CO2 in NaOH.

View larger version (13K): [in this window] [in a new window]   Fig. 3. Results of batch experiments for normal soils showing the aqueous concentration of 14C through time. The relative concentration used in this figure and the other figures represents the ratio between the measured concentration and the initial concentration. The batch data shown are from the two different initial aqueous concentrations, which are fitted with the model described in Eq. [1], [2], and [4].

View larger version (13K): [in this window] [in a new window]   Fig. 4. Results of batch experiments for autoclaved soils showing the aqueous concentration of 14C through time. The variables HC and HA represent initial aqueous concentration of 0.738 mg L–1 using clear and amber vials, respectively. The variables LC and LA represent initial aqueous concentration of 0.406 mg L–1 and clear and amber vials, respectively.

View larger version (15K): [in this window] [in a new window]   Fig. 5. Simulation of (A) aqueous concentrations of testosterone and its metabolite through time, (B) sorbed concentrations of testosterone and its metabolite through time, and (C) 14CO2 created from testosterone mineralization through time. These simulations were calculated using the parameters obtained from fitting Eq. [1], [2], and [3] to the experimental batch data.

View larger version (13K): [in this window] [in a new window]   Fig. 6. The results of combustion experiment showing the distribution of 14C with depth in the soil columns at the completion of the miscible-displacement Experiments 1 and 2.

View larger version (23K): [in this window] [in a new window]   Fig. 7. Breakthrough curves of testosterone and its metabolite for miscible-displacement (A) Experiment 1 and (B) Experiment 2.

View larger version (17K): [in this window] [in a new window]   Fig. 8. Chloride ion breakthrough curves for miscible-displacement (A) Experiment 1 and (B) Experiment 2.