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020 ▼a 9780438351394
035 ▼a (MiAaPQ)AAI10831521
035 ▼a (MiAaPQ)umn:19387
040 ▼a MiAaPQ ▼c MiAaPQ ▼d 248032
0820 ▼a 631.4
1001 ▼a Hall, Kathleen Erin.
24510 ▼a Biochar as a Sorbent for Naturally Occurring and Synthetic Agricultural Chemicals.
260 ▼a [S.l.] : ▼b University of Minnesota., ▼c 2018
260 1 ▼a Ann Arbor : ▼b ProQuest Dissertations & Theses, ▼c 2018
300 ▼a 132 p.
500 ▼a Source: Dissertation Abstracts International, Volume: 80-01(E), Section: B.
500 ▼a Adviser: Kurt A. Spokas.
5021 ▼a Thesis (Ph.D.)--University of Minnesota, 2018.
520 ▼a The idea of adding biochar to soil to sequester carbon and improve fertility has soared in popularity over the past few decades; however, a strong scientific understanding of this material and its environmental effects is still lacking. This body of work explores biochar's interactions with chemicals, both naturally occurring (i.e., allelochemicals) and anthropogenically applied (i.e., herbicides), and sheds light on the mechanisms involved and our ability to predict and optimize its sorptive behavior.
520 ▼a The first chapter investigates how the feedstock material from which a biochar is produced impacts its sorptive behavior toward allelochemicals. Mixing different feedstocks, such as pine chips and poultry litter, is thought to be a way to create "designer biochars" that combine the beneficial properties of each feedstock. However, results from this study revealed that mixing feedstock materials did not have predictable effects on organic compound sorption.
520 ▼a The second chapter begins to evaluate biochar-chemical interactions in soil to better understand realistic applications of biochar as a sorbent. Here, the leaching potentials of six different herbicides were assessed in vulnerable Hawaiian soils, and biochar was tested as a tool to reduce the transport of the most mobile herbicide, aminocyclopyrachlor. It was found that none of the four biochar amendments tested significantly altered the leaching potential of aminocyclopyrachlor in these soils based on fate and transport models.
520 ▼a In the third chapter, the focus shifts more towards understanding the mechanisms of biochar-herbicide interactions. Here we specifically looked at glyphosate, the world's most widely used herbicide, and found that biochar macroporosity and specific surface functionality influenced glyphosate sorption. Additionally, pre-pyrolysis addition of Fe and Cu had no significant effect on sorption. Results from this work also demonstrated the reversibility of glyphosate sorption on biochar in the presence of phosphate, suggesting similar binding mechanisms and potential interferences from phosphate fertilizers.
520 ▼a The fourth chapter continues to investigate the sorption mechanisms responsible for the observed biochar-herbicide interactions and simultaneously assesses our ability to optimize biochars for sorption through activation treatments. It was found that activation of a low-temperature biochar by hydrogen peroxide can improve the removal of organic acid herbicides from aqueous solution, but was of little value in optimizing the removal of non-ionizable herbicides. The improved removal efficiency was attributed to pH effects and charge-based interactions with biochar.
520 ▼a Collectively, the research presented in this dissertation highlights the variability of biochar's sorptive behavior and illustrates the challenges in predicting this behavior, particularly when feedstocks are combined. While the sorptive applications in soil initially appear limited, there is potential to improve the sorption capacity of these materials through activation, and more targeted improvements will be possible once sorption mechanisms are better understood.
590 ▼a School code: 0130.
650 4 ▼a Soil sciences.
650 4 ▼a Environmental science.
690 ▼a 0481
690 ▼a 0768
71020 ▼a University of Minnesota. ▼b Land and Atmospheric Science.
7730 ▼t Dissertation Abstracts International ▼g 80-01B(E).
773 ▼t Dissertation Abstract International
790 ▼a 0130
791 ▼a Ph.D.
792 ▼a 2018
793 ▼a English
85640 ▼u http://www.riss.kr/pdu/ddodLink.do?id=T15013679 ▼n KERIS
980 ▼a 201812 ▼f 2019
990 ▼a 관리자