Grant Information
| Knowledge Area | Subject of Investigation | Field of Science | Percent |
|---|---|---|---|
| 133 - Pollution Prevention and Mitigation | 110 - Soil | 2000 - Chemistry | 60% |
| 133 - Pollution Prevention and Mitigation | 110 - Soil | 2050 - Hydrology | 40% |
Veterinary pharmaceuticals and hormones in animal manures are chemicals of emerging concerns (CECs), resulting in surface water contamination, bacteria antibiotic resistance, and endocrine disruption of humans and animals. CEC-contaminated manures are typically applied to agricultura fields. As CECs tend to sorb strongly to major soil geosorbents, i.e., clay minerals, amorphous organic matter (AOM), and black carbon/biochar (BC), topsoils and especially certain geosorbent particles become highly enriched in CECs. We envision that CEC-enriched geosorbent particles mobilized from top soils and transported in surface runoff or to shallow tile-drainage water can contribute a substantial CEC load to surface waters. We will mechanistically examine CEC sorption and transport in surface runoff and subsurface flows. Objectives are: 1) Determine sorption capacities of clay minerals, AOM, and BC for representative CECs and assess possible sorption attenuation of CECs by manure- and natural biomass- derived organic acids; 2) Develop a mechanistic, predictive sorption model based on additive sorption by these geosorbents and validate this technique with whole soils and soils amended with biochars, 3) Investigate and model the facilitated transport of CECs by geosorbent colloids in surface and shallow subsurface flows. Knowledge gained will help improve process-based modeling of CEC transport in surface runoff and shallow drainage waters. Improved assessment of CEC retention and transport in soil ecosystems will contribute to management strategies to mitigate the spread of CECs in the environment, thus protecting human and ecosystem health.
The major focus of this project is to determine the mechanisms by which veterinary pharmaceuticals and hormones (i.e., CECs) might be transported to surface waters via colloid-facilitated transport in either surface runoff or subsurface flows to tile drainage. Our long-term goal is to create fundamental knowledge and predictive tools that can be used to mitigate proliferation of CECs from agricultural soils to surface waters. We propose to link the mechanistic understanding of CEC sorption by soil geosorbents (i.e., clay minerals, amorphous organic matter [AOM], and black carbon [BC]) with facilitated transport by the same geosorbents. Major objectives of this project are:
A combination of experimental techniques across molecular, batch-type, soil-column, and plot scales will be used and integrated to achieve Objectives 1-3. Batch sorption isotherms will be measured, and sorption parameters will be explained in terms of CEC chemistry combined with fundamental geosorbent properties such as specific surface area, functionality, and pore-size distribution. Spectroscopy, X-ray diffraction, and computational chemistry will aid the mechanistic understanding developed by our team. Sorption parameters and soil properties will be used to develop a predictive model to estimate sorption properties of soils. Transport and modeling of CEC, geosorbent colloids, and CEC-geosorbent complexes in surface runoff and vertical drainage water will be studied using plot-scale rainfall simulation and Darcy-scale column transport experiments. More specifically, for Objective 1 we will use use lincomycin, sulfamethoxazole, tetracycline and monensin from four antibiotic classes as our model antibiotics and 17β-estradiol as our model hormone. Sorption of these representative CECs on clays and biochars will be measured using batch sorption equilibration techniques. A series of initial solute concentrations will be prepared for each CEC in aqueous solution, mixed with clay minerals and BCs. After reaching equilibrium, the geosorbent and solution will be separated by centrifugation and ultrafiltration through 25-nm mixed cellulose ester membrane (Millipore). The supernatant will be analyzed by LC-MS/MS (Shimazu Prominence high-performance liquid chromatograph coupled to an Applied Biosystems Sciex 3200 triple quadrupole mass spectrometer). Sorption of CECs on dissolved AOM will be determined using a novel approach that uses Waters/OASIS hydrophilic- and hydrophobic-balanced (HLB) cartidges in solid-phase extraction to separate free CEC species and CECs complexed with Elliott soil humic acid (i.e., a model AOM). Sorption of CECs on AOM attached to soil minerals will be measured by a quartz crystal microbalance with dissipation monitoring (QCM-D) by flowing the CEC solution over the AOM-coated quartz sensor. The sorption attenuation experiments will be performed by including low molecular weight organic acids (i.e., acetic, oxalic, and citric acids), tannic acid, or Elliott soil humic acid in sorption solutions. For Objective 2, the sorption measured for these three geosorbents may be summed to predict sorption properties of a whole soil, for which we have chosen the Webster soil that is rich in all three geosorbents. Additionally, we will also amend the Webster soil with a biochar with high CEC sorption capacity and again attempt to validate our predictive sorption model. For Objective 3, colloid-facilitated transport of CECs over soil surfaces and through soil profiles will be quantified. We will perform laboratory rainfall simulation and column experiments utilizing soil-packed boxes and columns, and subsequent mathematical modeling (for data interpretation and analysis), so as to quantify CEC transport under realistic rainfall intensity and flow conditions. We will then use the results of Objectives 1-2 to mechanistically link these transport phenomena to geosorbent-CEC complexation chemistry. We propose to measure the concentrations of each geosorbent (AOM, clay minerals, and BCs/biochars) in runoff water and to quantify the flux of CEC associated with each geosorbent species. In addition to this work on whole soils, we will examine the transport of biochars in surface runoff and shallow subsurface flow in the context of biochar soil amendment. The outcome of this fundamental research will mainly be evaluated by the quality and number of conference presentations and referred journal publications and, and the academic progress and achievement of graduate student and postdoctoral researchers supported through this project. Specifically, the quality and impact of journal publications can be evaluated by the impact of the journal and the papers themselves. The accumulated citation of the papers up to the date of final report will be reported. The presentations on scientific meetings will be tracked. The degree completion of graduate students and the career advancement of both graduate student and postdoc will be recorded.
Target Audience
The primary target audience is scientific community and extension professionals in the field of environmental science and engineering, soil and water science, animal manure management, etc.
Changes / Problems
Nothing Reported
Training & Professional Development
The project provided the support for the work of fourgraduate students, two postdoctoral research associates, one undergraduate student, and two high school students. The interactions among the students, postdocs, and faculty benefited the professional development of students, postdocs and faculty. The project also provided travel support for the attendance in multiple scientific conferences.
Dissemination Streams
The project results were published in 5 refereed journal articles, and presented in 16 conference presentations. Also, more than 25 invited presentations were delivered in universities and research institutes, and at least 3 more manuscripts will be submitted for journal publications. Our work was also featured in the Futures Magazine (Volume 33, Nos. 1 & 2, 2015) at Michigan State University that reached broader communities and stakeholders. These activities have increased the impact of our research effort.
Next Reporting Steps
Nothing Reported
Target Audience
The primary target audience during this reporting period is scientific community and extension professionals in the field of environmental science and engineering, soil and water science, animal manure management, etc.
Changes / Problems
Nothing Reported
Training & Professional Development
The project provided the support for two graduate students. The project provided travel support for one graduate student to attend the ASA, CSSA & SSSA International Annual Meeting to present researchresults and to interact with fellow researchers.
Dissemination Streams
The results have been presented in one national and two international scientific meetings. One invited presentation was given at an international institution. These activities have increased the impact of our research effort. One manuscript was published, one article was in revision, two manuscripts are currently under preparations, and at least two more manuscript preparations are planned.
Next Reporting Steps
For the remaining project period, we plan to complete the rainfall simulation experiments to understand the pharmaceutical transport in surface and subsurface flow in a biochar-amended Mollisol soil. We will also complete the writing of two manuscripts summarizing the long-term sorption of lincomycin by biochars, and the facilitated transport of pharmaceuticals by biochar nanoparticles at varying solution pH in saturated sand columns. <br><br>
<br>What was accomplished under these goals? In the past year, we investigated the facilitated transport of antibiotics by biochar under simulated rainfall using an agricultural Mollisol in corn-soybean rotation under no-till from Central Indiana. The rainfall simulations at 2 rainfall intensities were performed to represent a normal (50 mm hr−1) and a 200-year return period storm (100 mm hr−1) for the U.S. Midwest. The rates of biochar application (0, 1, and 2% by weight) were chosen to be consistent with the rates used in the literature. The compounds used in this study (lincomycin, tylosin, and monensin) were selected because they are normally administrated to animals, and found in manure and in streams. During each rainfall simulation, surface runoff and subsurface drainage (infiltration) were collected for analysis. In addition, after the rainfall simulations, soil samples from the rain boxes were collected. Samples from runoff and infiltration were vacuum-filtered using 0.45-µm filter to collect water and retain the solid material. Water samples from the surface runoff and infiltration were analyzed for lincomycin, tylosin, and monensin using an UPLC-MS-MS. The materials retained on the vacuum filter were fractionated to obtain the biochar from the sediments using the density fractionation approach. Both materials (biochar and sediments) were being extracted using the accelerated solvent extraction technique to remove or desorb lincomycin, tylosin, and monensin that were sorbed on both materials. The results showed that pharmaceutical losses from a biochar-amended soil were dependent primarily on the type of compound and drainage type (i.e. surface and subsurface) and to a lesser extent on the rainfall intensity and the rate of biochar application. Surface losses follow the trend of lincomycin > monensin >> tylosin for both rainfall intensities; of the total applied, up to 0.9% and 0.02% of lincomycin and tylosin were lost via surface runoff. However, losses via infiltration followed the trend of monensin >> lincomycin > tylosin, where ~up to 14.3 and 0.87% of the applied monensin and lincomycin, respectively, were accounted in the water infiltrated. Monensin losses in surface runoff increased with increasing biochar application rates at both rain intensities. Similar trend was observed for the monensin losses via infiltration with 50 mm h−1 rainfall intensity. There was no apparent effect of biochar application rate on the losses of lincomycin or tylosin. To elucidate if the higher losses of lincomycin in surface runoff, relative to the other compounds, were linked to the facilitated transport, water samples were filtered using a sequential size-filter scheme (0.45, 0.2, and 0.1 µm). Preliminary results indicate that concentrations decreased as the size of filter decreased regardless of the biochar treatment, including the control (no biochar); these observations suggest that the lincomycin losses in surface runoff may be associated in part to the facilitated transport via sediments/biochar. No data is available yet on the desorbed compounds from the sediment/soil. The anticipated graduation for the MS student is Spring 2018. Two manuscripts are expected from this part of the project: one on the surface and infiltration losses of the compounds, and the other one on the desorption of compounds from the sediments/biochar and the linkage to the facilitated transport of the compounds with sediments/biochar. We have also written a manuscript on the release of dissolved organic carbon from biochars, which was under review in Environmental Science and Technology. We are currently preparing a manuscript on the long-term sorption behaviors of lincomycin to biochars. <br><br><b>Publications</b><br>
Target Audience
The primary target audience reached by our efforts during this reporting period is scientific community and extension professionals in the field of environmental science and engineering, soil and water science, animal manure management, etc.
Changes / Problems
Nothing Reported
Training & Professional Development
The project provided the support for two graduate students. The project provided travel support for one graduate student to attend the ASA, CSSA & SSSA International Annual Meeting and one graduate student to attend the AGU annual Fall Meeting to present their results and to interact with fellow researchers. The PD's attendances at the annual USDA PD meeting, the ASA, CSSA, & SSSA International Annual Meeting, the AGU annual Fall Meeting, and the 252nd ACS National Meeting & Exposition were supported by the project.
Dissemination Streams
The results have been presented in five national and two international scientific meetings. Five invited presentations were given at international institutions. These activities have thus increased the reach and impact of our research effort. Four manuscripts were published, one article is in press, four manuscripts are currently under preparations, and at least two more manuscript preparations are planned.
Next Reporting Steps
Next year, we plan to investigate the facilitated transport of pharmaceuticals by biochar nanoparticles at varying solution pH in saturated sand columns. We will continue the rainfall simulation experiments to understand the pharmaceutical transport in surface and subsurface flow in biochar-amended soils. <br><br>
<br>What was accomplished under these goals? In Year 3 of the project, we investigated the facilitated transport of antibiotics (i.e., lincomycin, oxytetracycline, and sulfamethoxazole) by biochar nanoparticles at solution pH 7 and solution ionic strength of 0.1, 1, and 10 mM in saturated sand columns. This work is a key component of the project Objective 3 examining the subsurface transport of pharmaceuticals in porous media in the context of biochar soil amendment. The breakthrough curve results suggested that without biochar nanoparticles, lincomycin transport increased with increasing ionic strength, whereas the transport of oxytetracycline and sulfamethoxazole was not significantly changed. In the absence of biochar nanoparticles and at ionic strength of 0.1-10 mM, approximately 100% of injected sulfamethoxazole was transported through the column, but 100% of injected oxytetracycline was retained in the column. In the presence of biochar nanoparticles, free antibiotics in solution phase or antibiotics associated with biochar nanoaprticles were both transported through the sand columns. Total antibiotics transport decreased with increasing ionic strength. In the event of low solution ionic strength (e.g., 0.1 mM) often associated with rainfall or irrigation, biochar nanoparticles facilitated the transport of lincomycin, but decreased its transport at higher ionic strength. Biochar nanoparticles facilitated the transport of oxytetracycline that otherwise was strongly retained in the sand column at all ionic strengths. For sulfamethoxazole that was minimally retained in the sand column, biochar nanoparticles decreased its transport. Therefore, assessing the role of fine biochar particles on the transport of antibiotics needs to consider soil water chemistry. As part of biochar soil amendment strategies, one needs to consider the aging of biochar particles once applied in soils. We continued the work on the leachable organic carbon from 46 biochars produced from a range of feedstock materials and pyrolysis conditions. The leachable organic carbon were extracted with 0.1 M HCl, deionized water, and 0.1 M NaOH, and their organic carbon content and UV-Vis spectra were measured. Selected unwashed bulk biochars, washed bulk biochar, and the leachable organic carbon were also characterized by solid-state NMR. Our results showed that: biochars released more organic carbon under alkaline condition; biochars produced at lower pyrolysis temperature had greater leachable organic carbon content; and biochars produced under faster pyrolysis had greater leachable organic carbon content. We have also developed correlation equations allowing for fast and accurate estimation of leachable organic carbon concentrations from UV absorbance at 254 nm for the three extraction solutions, respectively. The leached organic carbon had lower aromatic carbon content and was less condensed compared to the bulk biochars, confirmed with both the UV spectra data and the solid-state NMR data. The release of leachable organic carbon from the biochars affected the sorption of lincomycin to biochars, highlighting the importance of understanding biochars aging on soil biochar amendment as a strategy to reduce the transport and bioavailability of pharmaceuticals. Additionally, our collaborators at USDA/ARS National Soil Erosion Research Lab and Purdue University have started rainfall simulation experiments for soils free of pharmaceuticals or biochars, soils with pharmaceuticals (i.e., lincomycin, monensin, and tylosin) and without biochars, and soils with pharmaceuticals and biochar amendment rate of 1%, and 2%, all under a rainfall intensity of 5 cm/hour. This work is currently ongoing. <br><br><b>Publications</b><br>
Target Audience
The primary target audience reached by our efforts during this reporting period is scientific community and extension professionals in the field of environmental science and engineering, soil and water science, animal manure management, etc.
Changes / Problems
Nothing Reported
Training & Professional Development
The project provided the support for three graduate students, and one postdoctoral research associate. The project provided travel support forone graduate student to attend the ASA, CSSA & SSSA International Annual Meeting to present the results and interact with fellow researchers. The PD's attendances at the annual USDA PD meeting, and the ASA, CSSA, & SSSA International Annual Meeting were supported by the project.
Dissemination Streams
The results have been presented in two national and international scientific meetings. Six invited presentations were given at domestic and international institutions. These activities have thus increased the reach and impact of our research effort. One manuscript was published, and one manuscript is currently under revision, four manuscripts under preparations, andat least two more manuscript preparations planned.
Next Reporting Steps
Next year, we plan to continue the transport study of pharmaceuticals as influenced by the presence of biochar particles in soils. We will initiate the rainfall simulation experiments to understand the pharmaceutical transport in surface and subsurface flow in biochar-amended soils. For the rainfall simulation experiments we will analyze physicochemical properties of biochar selected as soil for this experiments, investigate the sorption of the target pharmaceuticals on the selected biochars, and evaluate the transport of pharmaceuticals in surface runoff and subsurface drainage during rainfall simulatio <br><br>
<br>What was accomplished under these goals? In Year 2 of the project, we performed additional screening test for lincomycin sorption by 35 biochars at solution pH 6 and pH 9 for equilibration duration of 1 day and 1 month, respectively. This work was justified based on the Year 1 results showing that lincoymcin sorption by biochars was found to a function of solution pH, and equilibration period was important due to lincomycin diffusion into biochar pores. The BET-CO2 specific surface area for these 35 biochars were also determined. Statistical analyses are underway to correlate lincomycin sorption at varying experimental conditions to biochar physicochemical properties. Preliminary results indicated that disparate correlations were observed depending on the levels of solution pH and biochar ash content. Further analyses are being undertaken to identify responsible mechanisms. We have investigated the release of dissolved organic matter (DOM) from biochars of varying feedstock and pyrolysis processes, and then the effect of DOM release on lincomycin sorption. Our results showed that low temperature biochars released more DOM than high temperature biochars, and the DOM release increased lincomycin sorption because of increased surface area and fraction of finer biochar particles. Finally, we have investigated sorption of 17β-estradiol by biochars and sand, and performed 17β-estradiol column transport experiments. We found decreased 17β-estradiol transport through biochar-amended sand column than through biochar-free sand column. Additionally, our collaborators at USDA/ARS National Soil Erosion Research Lab and Purdue University have started necessary procedure preparation for rainfall simulation experiments, including (1) fractionation of the soil aggregates using wet sieving procedures; (2) density separation of the particulate organic matter from the above soil aggregates using sodium polytungstate; (3) contaminant sorption technique; (4) water quality analysis; and (5) familiarization with analytical instruments for biochar characterization (including FTIR, TGA, and X-ray diffraction). Relevant effort also included biochar characterization and participation in a 'ring trial' with a group of about 20 other scientists from around the world. Analytical methods have been developed to study biochars and the fate of biochar amended in soils, including FTIR spectroscopy and thermal analysis methods to characterize a diverse suite of biochars prepared from different feedstocks and pyrolysis temperatures. In addition, the fate of biochars amended to four contrasting soils over a two-year period was investigated. <br><br><b>Publications</b><br>
Target Audience
The primary target audience reached by our efforts during this reporting period is scientific community and extension professionals in the field of environmental science and engineering, soil and water science, animal manure management, etc.
Changes / Problems
Nothing Reported
Training & Professional Development
The project provided the support for one graduate student, and one postdoctoral research associate. Additionally, two high school students participated in the project during the summer of 2014, which gave the high school students a valuable research experience in a university research lab, and also the graduate student and postdoc opportunities to guide high school researchers. The project provided travel support for the graduate student to attend the 248th ACS National Meeting and the ASA, CSSA & SSSA International Annual Meeting to present the results and interact with fellow researchers. The PD's attendances at the annual USDA PD meeting, EmCon 2014, and the ASA, CSSA, & SSSA International Annual Meeting were supported by the project.
Dissemination Streams
The results have been presented in four national and international scientific meetings, thus increasing the impact and reach of our research efforts. One manuscript is currently under preparation for journal publication, with at least two more manuscripts planned.
Next Reporting Steps
Next year, we plan to expand the sorption studies to other antibiotics and hormone, continue the study on the attenuation effect of organic acids, initiate the sorption study of antibiotics and hormone on attached natural organic matter, develop the sorption model of the whole soils, and begin the preliminary work for surface and subsurface transport studies. <br><br>
<br>What was accomplished under these goals? In Year 1 of the project, we screened sorption capacities of 35 biochar and investigated sorption kinetics and isotherms of 17 biochars for antibiotic lincomycin. We studied lincomycin sorption to 4 manure-derived biochars in detail for effects of biochar dosage, ionic strength, and solution pH. We also investigated the attenuation effect of low-molecular-weight organic acids (i.e., acetic, fumaric, and citric acids) on tetracycline sorption by biochar. we started the preliminary work on mechanistic, predictive sorption model based on additive sorption by the geosorbents. The screening test revealed that lincomycin sorption varied significantly with biochar feedstocks and pyrolysis temperature. Detailed statistical analysis such as principal component analysis is planned to correlate lincomycin sorption with biochar properties. Lincomycin sorption by biochars followed two-stage kinetics with a rapid initial sorption controlled by surface reaction and a slow long-term sorption by pore diffusion. There was an interplay of ionic strength and solution pH effects on lincomycin sorption. We observed that tetracycline sorption by biochar was attenuated by the presence of organic acids, and the attenuation effect was the greatest for citric acid and similar for acetic and fumaric acids. Increasing organic acid concentration resulted in increased attenuation effect. We envisioned that at least three manuscripts could be resulted fromt these results. Currently, one manuscript is under preparation. <br><br><b>Publications</b><br>