Assessment of the retardation of selected herbicides onto Danube sediment based on small column tests
Purpose: This study utilizes column tests to investigate the retardation of certain herbicides with different hydrophobicities (atrazine, alachlor and trifluralin) during transport through surface Danube sediment. The influence of water matrix on the retardation factor Rd and Freundlich constant Kf...
| Main Authors: | , , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2021
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/151407 |
| _version_ | 1811677869549551616 |
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| author | Maćerak, Anita Leovac Ivančev-Tumbas, Ivana Börnick, Hilmar Ilić, Gordana Isakovski, Marijana Kragulj Maletić, Snežana |
| author2 | School of Physical and Mathematical Sciences |
| author_facet | School of Physical and Mathematical Sciences Maćerak, Anita Leovac Ivančev-Tumbas, Ivana Börnick, Hilmar Ilić, Gordana Isakovski, Marijana Kragulj Maletić, Snežana |
| author_sort | Maćerak, Anita Leovac |
| collection | NTU |
| description | Purpose: This study utilizes column tests to investigate the retardation of certain herbicides with different hydrophobicities (atrazine, alachlor and trifluralin) during transport through surface Danube sediment. The influence of water matrix on the retardation factor Rd and Freundlich constant Kf is investigated. The results are compared with batch tests to establish whether different methodologies result in similar or different conclusions. Materials and methods: A stainless steel column was filled with natural Danube sediment. Three water matrices were investigated: synthetic, Danube surface, and deep groundwater rich in natural organic matter (NOM). The goal was to examine whether different water matrices would result in changes in the Rd and corresponding Kf values. After a tracer experiment, single herbicide solutions were tested in the three water matrices. Herbicides were analyzed by gas chromatography coupled with electron capture detector (GC/ECD). Retardation factors obtained in the column experiments were calculated using Transmod software (version 2.2). The Kf values calculated were compared with the values obtained in previous batch experiments. Results and discussion: A breakthrough curve (BTC) for trifluralin could not be obtained during the experiment. Atrazine Rd values were almost the same in the natural matrices (54 and 55 for the ground and surface waters, respectively), and lower in the synthetic water (40). Alachlor Rd values in the three water matrices were very similar (30–35). The corresponding Kf values for alachlor (8.47–17.4) were lower than those of atrazine (13.5–27.9). These results differ from those obtained by earlier batch tests, which showed similar Kf values for both atrazine (4.4–9.2) and alachlor (4.43–10.35) in all three matrices. In contrast to the results observed during the batch tests, the column tests exhibited higher Kf values in the natural water matrices than the synthetic water, possibly due to the influence of dissolved organic carbon on herbicide sorption. Conclusions: Of the three herbicides investigated, the smallest retardation was observed for alachlor. This was unexpected given the relative hydrophobicities of alachlor and atrazine. The potential risk of transport through the sediment may therefore be greater for alachlor than the other two herbicides. This was indicated neither by the batch tests nor from the Koc–Kow estimations. Both herbicides exhibited similar Kd and Kf values in the batch tests, and lower values in the natural water matrices. In comparison, the column tests showed higher Kf values, with higher values in the natural matrices than in the synthetic water matrix. |
| first_indexed | 2024-10-01T02:44:13Z |
| format | Journal Article |
| id | ntu-10356/151407 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T02:44:13Z |
| publishDate | 2021 |
| record_format | dspace |
| spelling | ntu-10356/1514072021-06-23T11:08:22Z Assessment of the retardation of selected herbicides onto Danube sediment based on small column tests Maćerak, Anita Leovac Ivančev-Tumbas, Ivana Börnick, Hilmar Ilić, Gordana Isakovski, Marijana Kragulj Maletić, Snežana School of Physical and Mathematical Sciences Science::Chemistry Column Experiments Geosorption Purpose: This study utilizes column tests to investigate the retardation of certain herbicides with different hydrophobicities (atrazine, alachlor and trifluralin) during transport through surface Danube sediment. The influence of water matrix on the retardation factor Rd and Freundlich constant Kf is investigated. The results are compared with batch tests to establish whether different methodologies result in similar or different conclusions. Materials and methods: A stainless steel column was filled with natural Danube sediment. Three water matrices were investigated: synthetic, Danube surface, and deep groundwater rich in natural organic matter (NOM). The goal was to examine whether different water matrices would result in changes in the Rd and corresponding Kf values. After a tracer experiment, single herbicide solutions were tested in the three water matrices. Herbicides were analyzed by gas chromatography coupled with electron capture detector (GC/ECD). Retardation factors obtained in the column experiments were calculated using Transmod software (version 2.2). The Kf values calculated were compared with the values obtained in previous batch experiments. Results and discussion: A breakthrough curve (BTC) for trifluralin could not be obtained during the experiment. Atrazine Rd values were almost the same in the natural matrices (54 and 55 for the ground and surface waters, respectively), and lower in the synthetic water (40). Alachlor Rd values in the three water matrices were very similar (30–35). The corresponding Kf values for alachlor (8.47–17.4) were lower than those of atrazine (13.5–27.9). These results differ from those obtained by earlier batch tests, which showed similar Kf values for both atrazine (4.4–9.2) and alachlor (4.43–10.35) in all three matrices. In contrast to the results observed during the batch tests, the column tests exhibited higher Kf values in the natural water matrices than the synthetic water, possibly due to the influence of dissolved organic carbon on herbicide sorption. Conclusions: Of the three herbicides investigated, the smallest retardation was observed for alachlor. This was unexpected given the relative hydrophobicities of alachlor and atrazine. The potential risk of transport through the sediment may therefore be greater for alachlor than the other two herbicides. This was indicated neither by the batch tests nor from the Koc–Kow estimations. Both herbicides exhibited similar Kd and Kf values in the batch tests, and lower values in the natural water matrices. In comparison, the column tests showed higher Kf values, with higher values in the natural matrices than in the synthetic water matrix. 2021-06-23T11:08:22Z 2021-06-23T11:08:22Z 2019 Journal Article Maćerak, A. L., Ivančev-Tumbas, I., Börnick, H., Ilić, G., Isakovski, M. K. & Maletić, S. (2019). Assessment of the retardation of selected herbicides onto Danube sediment based on small column tests. Journal of Soils and Sediments, 19(2), 964-972. https://dx.doi.org/10.1007/s11368-018-2084-2 1439-0108 https://hdl.handle.net/10356/151407 10.1007/s11368-018-2084-2 2-s2.0-85050262249 2 19 964 972 en Journal of Soils and Sediments © 2018 Springer-Verlag GmbH Germany, part of Springer Nature. All rights reserved. |
| spellingShingle | Science::Chemistry Column Experiments Geosorption Maćerak, Anita Leovac Ivančev-Tumbas, Ivana Börnick, Hilmar Ilić, Gordana Isakovski, Marijana Kragulj Maletić, Snežana Assessment of the retardation of selected herbicides onto Danube sediment based on small column tests |
| title | Assessment of the retardation of selected herbicides onto Danube sediment based on small column tests |
| title_full | Assessment of the retardation of selected herbicides onto Danube sediment based on small column tests |
| title_fullStr | Assessment of the retardation of selected herbicides onto Danube sediment based on small column tests |
| title_full_unstemmed | Assessment of the retardation of selected herbicides onto Danube sediment based on small column tests |
| title_short | Assessment of the retardation of selected herbicides onto Danube sediment based on small column tests |
| title_sort | assessment of the retardation of selected herbicides onto danube sediment based on small column tests |
| topic | Science::Chemistry Column Experiments Geosorption |
| url | https://hdl.handle.net/10356/151407 |
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