Influence of soil properties and test conditions on sorption and desorption of testosterone

In this study, batch sorption and desorption experiments were conducted for testosterone using four agricultural soils and five clay minerals. Significant differences in sorption behavior were observed between abiotic and biotic systems. The Freundlich sorption coefficient Kf (µg per g)/(µg per mL) ranged from 8.53 to 74.46 for soils and from 35.28 to 1243 for clays. The maximum sorption capacity (µg per g) of soils ranged from 25.25 to 440.61 for soils and 168.46 to 499.84 for clays. Correlation of sorption model parameters with soil properties indicated that both clay content and soil organic matter are important variables in predicting testosterone sorption behavior. Observed testosterone desorption from agricultural soils ranged from approximately 14 to 100 percent after 3 desorption cycles, and the desorption percentage decreased as the initial testosterone concentration decreased. Temperature, ionic strength, the water/soil ratio and soil depth were determined to influence sorption and desorption of testosterone. Desorption significantly increase with the soil depth and with the increase in the water to soil ratio. Temperature had an inverse effect on the sorption capacity of the soils tested. Thermodynamic calculations showed that the enthalpy change of the soils tested were the range of 12.9-20.7 kJ per mol, indicating weak interaction between testosterone and soil. Our results suggest that additional studies on how soil particles with different size fractions affect hormones fate and transport are needed in order to determine the potential risk of testosterone leaching or runoff

Effect of rainfall timing and tillage on the transport of steroid hormones in runoff from manure amended row crop fields

Manure generated from concentrated animal feeding operations (CAFOs) represents one of the major sources of steroid hormones found in surface water. This paper presents results of a study conducted near Concord, NE to determine the effects of manure handling (compost vs. stockpile), tillage (no-till, plow plus disk and disk), and rainfall timing (24 h and 30 d after manure application (DAT)) on the transport of steroids from row crop fields via surface runoff. Manure was collected following a feedlot study where one set of female cattle were administered growth promoting steroids and mycotoxins and one set received no treatments. Manure was either stockpiled for 9 months or composted prior to application. Twelve of 17 steroids or their metabolites were identified in the manure that was applied at agronomic rates to cropland in a no-till production system for more than 5 years. Chemical analysis of runoff samples detected steroids in less than 50% of the runoff samples and less than 10% of the samples contained more than one individual steroid or mycotoxin. The median concentration of androgens, and progestagens in surface runoff samples decreased by more than 50% between the 1 DAT to 30 DAT sampling dates. The percentage of detections increased between 24-h and 30-d after manure application largely due to increased levels of mycotoxins produced by the Fusarium genus of fungi common to corn fields. In addition, the physical and chemical properties of the steroids result appear to contribute to their long term degradation once applied to the soil. Based on this study, the combination of stockpiling manure prior to application and incorporation into the soil would likely result in the least potential for steroid transport to surface waters

Destruction of chemical warfare surrogates using a portable atmospheric pressure plasma jet

Today’s reality is connected with mitigation of threats from the new chemical and biological warfare agents. A novel investigation of cold plasmas in contact with liquids presented in this paper demonstrated that the chemically reactive environment produced by atmospheric pressure plasma jet (APPJ) is potentially capable of rapid destruction of chemical warfare agents in a broad spectrum. The decontamination of three different chemical warfare agent surrogates dissolved in liquid is investigated by using an easily transportable APPJ. The jet is powered by a kHz signal source connected to a low-voltage DC source and with He as working gas. The detailed investigation of electrical properties is performed for various plasmas at different distances from the sample. The measurements of plasma properties in situ are supported by the optical spectrometry measurements, whereas the high performance liquid chromatography measurements before and after the treatment of aqueous solutions of Malathion, Fenitrothion and Dimethyl Methylphosphonate. These solutions are used to evaluate destruction and its efficiency for specific neural agent simulants. The particular removal rates are found to be from 56% up to 96% during 10 min treatment. The data obtained provide basis to evaluate APPJ’s efficiency at different operating conditions. The presented results are promising and could be improved with different operating conditions and optimization of the decontamination process

Influence of soil properties and test conditions on sorption and desorption of testosterone

In this study, batch sorption and desorption experiments were conducted for testosterone using four agricultural soils and five clay minerals. Significant differences in sorption behavior were observed between abiotic and biotic systems. The Freundlich sorption coefficient Kf (µg per g)/(µg per mL) ranged from 8.53 to 74.46 for soils and from 35.28 to 1243 for clays. The maximum sorption capacity (µg per g) of soils ranged from 25.25 to 440.61 for soils and 168.46 to 499.84 for clays. Correlation of sorption model parameters with soil properties indicated that both clay content and soil organic matter are important variables in predicting testosterone sorption behavior. Observed testosterone desorption from agricultural soils ranged from approximately 14 to 100 percent after 3 desorption cycles, and the desorption percentage decreased as the initial testosterone concentration decreased. Temperature, ionic strength, the water/soil ratio and soil depth were determined to influence sorption and desorption of testosterone. Desorption significantly increase with the soil depth and with the increase in the water to soil ratio. Temperature had an inverse effect on the sorption capacity of the soils tested. Thermodynamic calculations showed that the enthalpy change of the soils tested were the range of 12.9-20.7 kJ per mol, indicating weak interaction between testosterone and soil. Our results suggest that additional studies on how soil particles with different size fractions affect hormones fate and transport are needed in order to determine the potential risk of testosterone leaching or runoff

Effect of rainfall timing and tillage on the transport of steroid hormones in runoff from manure amended row crop fields

Manure generated from concentrated animal feeding operations (CAFOs) represents one of the major sources of steroid hormones found in surface water. This paper presents results of a study conducted near Concord, NE to determine the effects of manure handling (compost vs. stockpile), tillage (no-till, plow plus disk and disk), and rainfall timing (24 h and 30 d after manure application (DAT)) on the transport of steroids from row crop fields via surface runoff. Manure was collected following a feedlot study where one set of female cattle were administered growth promoting steroids and mycotoxins and one set received no treatments. Manure was either stockpiled for 9 months or composted prior to application. Twelve of 17 steroids or their metabolites were identified in the manure that was applied at agronomic rates to cropland in a no-till production system for more than 5 years. Chemical analysis of runoff samples detected steroids in less than 50% of the runoff samples and less than 10% of the samples contained more than one individual steroid or mycotoxin. The median concentration of androgens, and progestagens in surface runoff samples decreased by more than 50% between the 1 DAT to 30 DAT sampling dates. The percentage of detections increased between 24-h and 30-d after manure application largely due to increased levels of mycotoxins produced by the Fusarium genus of fungi common to corn fields. In addition, the physical and chemical properties of the steroids result appear to contribute to their long term degradation once applied to the soil. Based on this study, the combination of stockpiling manure prior to application and incorporation into the soil would likely result in the least potential for steroid transport to surface waters

N2O emissions from a cultivated mollisol: optimal time of day for sampling and the role of soil temperature

The correct use of closed field chambers to determine N2O emissions requires defining the time of day that best represents the daily mean N2O flux. A short-term field experiment was carried out on a Mollisol soil, on which annual crops were grown under no-till management in the Pampa Ondulada of Argentina. The N2O emission rates were measured every 3 h for three consecutive days. Fluxes ranged from 62.58 to 145.99 ∝g N-N2O m-2 h-1 (average of five field chambers) and were negatively related (R² = 0.34, p < 0.01) to topsoil temperature (14 - 20 ºC). N2O emission rates measured between 9:00 and 12:00 am presented a high relationship to daily mean N2O flux (R² = 0.87, p < 0.01), showing that, in the study region, sampling in the mornings is preferable for GHG