Progress 08/15/07 to 08/14/11
Outputs
OUTPUTS: This project deals with the fate of hormones in soils where they are added by land application of animal manure. Our long-term goal is to improve risk assessment of hormones in the environment, especially those derived from concentrated animal feeding operations (CAFOs). Here, we focus specifically on the role that organic colloids play in facilitating or retarding hormone migration in soil environments. We have chosen to study the estrogens estradiol and its primary metabolite estrone because: (1) they are produced by a number of domestic animals and accumulate in manure, (2) they have been shown to affect the endocrine systems of aquatic species like fish at low concentrations, and (3) they can serve as prototypes for predictions about the fate of other endocrine-disrupting chemicals commonly found in the environment. In this third year of the research project, we conducted kinetic studies to determine the rate at which estradiol and estrone could be adsorbed by three soil materials and by water-dispersible colloids (WDCs) (clay plus organic matter) isolated from those soil materials. We also determined the rate of degradation of estradiol to estrone in association with the WDCs. We fractionated swine manure into several solid-phase fractions (based on particle size and hydrophobicity) and determined the adsorption affinity of estradiol for each of those fractions. We shared this information at three annual meetings of the Soil Science Society of America. PARTICIPANTS: Michael L. Thompson and Robert Horton, Agronomy Department, Iowa State University TARGET AUDIENCES: The target audience for this project is the scientific community, which is reached primarily through presentations at scientific meetings and refereed journal articles. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
We determined how colloidal materials in manure and soils retain the two hormones estradiol and estrone. We found that estrogens, like 17-beta estradiol (E2) and estrone (E1), are strongly bound to soil organic matter with log Koc values varying from approximately 3 - 4 L g-1. Swine manure colloids differ from soil derived colloids in the type and amount of organic carbon present leading to different sorption behaviors and different potential for transport of bound estrogens. Swine manure colloids exhibited Kd values of 214 L kg-1(E2) and 224 L kg-1 (E1) in contrast to soil derived colloids which varied from 55 - 140 L kg-1 in the three soils investigated. We found that reaction kinetics for sorption of estrogens to these three soils do not appear to fit simple first- or second-order reaction models. Adsorption of estradiol and transformation of estradiol to estrone was more rapid in association with Hanlon and Clarion WDCs than with Zook WDCs. In addition, degradation plus adsorption of estrone was faster in association with Clarion WDCs than either Hanlon or Zook WDCs. There was a linear increase of estradiol sorption to the manure fractions up to a maximum equilibrium concentration of 59 -74 ug/L. At higher concentrations, however, a nonlinear increase in adsorption was observed. Characterization of the soil colloidal fractions by Fourier-transform infrared spectroscopy indicated qualitative differences in the organic matter of the soil WDCs and the manure colloids. The soil colloidal materials showed evidence of nonpolar aromatic groups, whereas the manure colloids were dominated by aliphatic components, carbohydrates, and peptides. We also measured the sorption of E2 by manure colloids in the presence of soil colloids. Dialysis tubing was used maintain separation of the two competing sorbents without acting as a barrier to the estrogen. At the end of a 24-h sterile incubation, the concentration of E2 in the liquid phase was quantified while the E2 concentration in the soil colloids was quantified after E2 was desorbed from the colloidal material. The quantity of E2 unaccounted for was assumed to be sorbed by the manure component. In the presence of manure colloids, E2 demonstrated a site-limited, Langmuir type of sorption to Clarion-derived colloids, compared to the linear sorption when the Clarion colloids were present alone. On the other hand, E2 sorption to Zook colloids was linear, with or without the manure colloids present. On the basis of our research, we now know that estrogen molecules are strongly associated with colloidal components in the host manure and may not readily transfer to soil organic matter once the manure is land applied. The estrogens may still be mobile in the soil environment, however, because the manure colloids can themselves move through the soil -- especially through continuous macropores. These observations suggest that the risk of estrogen mobility is increased if land application of manure immediately precedes leaching events associated with rainfall.
Publications
- Wei, X., M. Shao, R. Horton, and X. Han. 2009. Humic acid transport in water-saturated porous media. Environ. Model. Assess. DOI 10.1007/s10666-008-9186-y.
- Prater, J.R., R. Chatterjee, T. Chua, M.L. Thompson. and R. Horton. 2009. Impacts of Colloidal Material on the Fate of Estrogens in Soils. Abstract of presentation at the Soil Science Society of America International Annual Meeting, Pittsburgh, PA.
- Prater, J., T. Chua, M. Thompson, and R. Horton. 2010. The Role of Colloids in Estrogen Transport through Soil. Abstract 252-4. Soil Sci. Soc. Am. Annual Meetings Long Beach, CA. Oct. 31-Nov. 4, 2010.
- Chua, T., R. Chatterjee, and M. Thompson. 2010 Sorption of 17-beta-Estradiol (E2) by Swine Manure Fractions. Abstract 96-10. Soil Sci. Soc. Am. Annual Meetings Long Beach, CA. Oct. 31-Nov. 4, 2010.
- Prater, J., T. Chua, M. Thompson, and R. Horton. 2011. Sorption of Estrogens to Colloidal Material: Of Swine Manure and Soil Origin. Abstract 158-17. Soil Sci. Soc. Am. Annual Meetings, San Antonio, TX. Oct. 16-19, 2011.
- Chua, T. and M.L. Thompson. 2011. Sorption of 17-beta-Estradiol to Manure Components In the Presence of Soil Colloids. Abstract 292-4. Soil Sci. Soc. Am. Annual Meetings, San Antonio, TX. Oct. 16-19, 2011.
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Progress 08/15/09 to 08/14/10
Outputs
OUTPUTS: This project deals with the fate of hormones in soils where they are added by land application of cattle manure. Our long-term goal is to improve risk assessment of hormones in the environment, especially those derived from concentrated animal feeding operations (CAFOs). Here, we focus specifically on the role that organic colloids play in facilitating or retarding hormone migration in soil environments. We have chosen to study the estrogens estradiol and its primary metabolite estrone because: (1) they are produced by a number of domestic animals and accumulate in manure, (2) they have been shown to affect the endocrine systems of aquatic species like fish at low concentrations, and (3) they can serve as prototypes for predictions about the fate of other endocrine-disrupting chemicals commonly found in the environment. In this third year of the research project, we conducted kinetic studies to determine the rate at which estradiol and estrone could be adsorbed by three soil materials and by water-dispersible colloids (WDCs) (clay plus organic matter) isolated from those soil materials. We also determined that the rate of degradation of estradiol to estrone in association with the WDCs. Finally, we fractionated swine manure into several solid-phase fractions (based on particle size and hydrophobicity) and determined the adsorption affinity of estradiol for each of those fractions. We shared this information at the 2010 annual meeting of the Soil Science Society of America. PARTICIPANTS: Michael L. Thompson and Robert Horton, Agronomy Department, Iowa State University TARGET AUDIENCES: The target audience for this project is the scientific community, which is reached primarily through refereed journal articles. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
In this period of the project, we are determining how colloidal materials in manure and soils retain the two hormones estradiol and estrone. We found that reaction kinetics for sorption of estrogens to these three soils do not appear to fit simple first- or second-order reaction models. Adsorption of estradiol and transformation of estradiol to estrone was more rapid in association with Hanlon and Clarion WDCs than with Zook. In addition, degradation plus adsorption of estrone was more rapid in association with Clarion WDCs than either Hanlon or Zook. In studies of swine manure, we found that the <71 um fraction yield was the largest portion of the solid mass of the swine manure. Carbon contents of the manure fractions ranged from 231 to 459 g/kg while N content varied from 22 to 116 g/kg. Infrared spectroscopy of the manure fractions showed that autoclaving did not alter the nature of functional groups present in the fractions. There was a linear increase of estradiol sorption to the manure fractions up to a maximum equilibrium concentration of 59 -74 ug/L. At higher concentrations, however, a nonlinear increase in adsorption was observed. In the next project period, we will explore the conditions under which the retention of these hormones by colloidal components either enhances or retards their movement in the soil and over the soil. These experiments are crucial in the development, parameterization, calibration, and validation of hormone transport models that will be used to guide both management and regulation of land-applied manure.
Publications
- Prater, J., T. Chua, M. Thompson, and R. Horton. 2010. The Role of Colloids in Estrogen Transport through Soil. Abstract 252-4. Soil Sci. Soc. Am. Annual Meetings Long Beach, CA. Oct. 31 - Nov. 4, 2010.
- Chua, T., R. Chatterjee, and M. Thompson. 2010 Sorption of 17-beta-Estradiol (E2) by Swine Manure Fractions. Abstract 96-10. Soil Sci. Soc. Am. Annual Meetings Long Beach, CA. Oct. 31 - Nov. 4, 2010.
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Progress 08/15/08 to 08/14/09
Outputs
OUTPUTS: This project deals with the fate of hormones in soils where they are added by land application of cattle manure. Our long-term goal is to improve risk assessment of hormones in the environment, especially those derived from concentrated animal feeding operations (CAFOs). Here, we focus specifically on the role that organic colloids play in facilitating or retarding hormone migration in soil environments. We have chosen to study the estrogens estradiol and its primary metabolite estrone because: (1) they are produced by a number of domestic animals and accumulate in manure, (2) they have been shown to affect the endocrine systems of aquatic species like fish at low concentrations, and (3) they can serve as prototypes for predictions about the fate of other endocrine-disrupting chemicals commonly found in the environment. In this second year of the research project, we determined the distribution coefficients for the interactions of two estrogens, estradiol and estrone, with three soil materials and water-dispersible colloids (WDCs) isolated from those materials. We also investigated the intrinsic mobility of colloidal organic matter in soils. We shared this information at the annual meeting of the Soil Science Society of America, and we collaborated on a research paper dealing with colloid transport in soils. PARTICIPANTS: Michael L. Thompson and Robert Horton (PIs), Agronomy Department, Iowa State University. Teresita Chua, assistant scientist, Agronomy Department, Iowa State University. Jacob Prater, graduate student, Agronomy Department, Iowa State University. TARGET AUDIENCES: The target audience for this project is the scientific community, which is reached primarily through refereed journal articles. PROJECT MODIFICATIONS: Two of the original PIs (Khanal and Fang) have left Iowa State University and are no longer associated with this project.
Impacts
In this period of the project, we are determining how colloidal materials in manure and soils retain the two hormones estradiol and estrone. We found that WDCs had markedly higher organic carbon contents than their parent soil materials and were dominated by smectite in the mineral fraction for these three soils. The organic carbon contents were strongly correlated with adsorption intensity for these three Iowa soils and their WDCs, as evidenced by similar Koc values. But not all soil organic matter was the same with respect to adsorption. There were differences in log Koc values among the two alluvial soils and one till-derived soil. Moreover, water-dispersible colloids had higher Koc values than their parent soil materials. This was particularly true of the clay-rich that had also previously received biosolids amendments. In the remaining project period, we will explore the conditions under which the retention of these hormones by colloidal components either enhances or retards their movement in the soil and over the soil. These experiments are crucial in the development, parameterization, calibration, and validation of hormone transport models that will be used to guide both management and regulation of land-applied manure.
Publications
- Wei, X., M. Shao, R. Horton, and X. Han. 2009. Humic acid transport in water-saturated porous media. Environ. Model. Assess. DOI 10.1007/s10666-008-9186-y.
- Prater, Jacob R., R. Chatterjee, T. Chua, M.L. Thompson. and R. Horton. 2009. Impacts of Colloidal Material on the Fate of Estrogens in Soils. Abstract of presentation at the Soil Science Society of America International Annual Meeting, Pittsburgh, PA.
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Progress 08/15/07 to 08/14/08
Outputs
OUTPUTS: In this first year of the research project, we (1) identified, located, and sampled three soils with a range of properties that will provide the basis for our laboratory and field investigations over the course of the project; (2) completed basic physical and chemical characterization of the collected soil samples; (3) fractionated colloidal materials from the soils to use in our sorption and colloid transport experiments; (4) isolated from swine manure potentially mobile colloidal materials that range in size and hydrophobicity; (5) characterized the fractionated swine manure colloids with respect to carbon, nitrogen, phosphorus, sulfur, calcium, magnesium, and sodium, and (7) obtained infrared spectra of swine manure colloids to better understand the chemical composition of the manure colloidal fractions. All of these tasks lay the critical groundwork for the laboratory and field experiments dealing with colloid-mediated transport of hormones in manure-amended soils. PARTICIPANTS: Michael L. Thompson and Robert Horton, Agronomy Department, Iowa State University. TARGET AUDIENCES: The target audience for this project is the scientific community, which is reached primarily through refereed journal articles. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
In this project, we will determine how colloidal materials in manure and soils retain the two hormones estradiol and estrone. We will explore the conditions under which the retention of these hormones by colloidal components either enhances or retards their movement in the soil and over the soil. These experiments are crucial in the development, parameterization, calibration, and validation of hormone transport models that will be used to guide both management and regulation of land-applied manure.
Publications
- No publications reported this period
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