The Library
Water flow plays a key role in determining chemical biodegradation in water-sediment systems
Tools
Tools
Tools
Southwell, Rebecca V., Hilton, Sally L., Pearson, Jonathan M., Hand, Laurence H. and Bending, Gary D. (2023) Water flow plays a key role in determining chemical biodegradation in water-sediment systems. Science of The Total Environment, 880 . 163282. doi:10.1016/j.scitotenv.2023.163282 ISSN 0048-9697.
|
PDF
1-s2.0-S0048969723019010-main.pdf - Published Version - Requires a PDF viewer. Available under License Creative Commons Attribution 4.0. Download (1791Kb) | Preview |
Official URL: http://dx.doi.org/10.1016/j.scitotenv.2023.163282
Abstract
Before agrochemicals can be registered and sold, the chemical industry is required to perform regulatory tests to assess their environmental persistence, using defined guidelines. Aquatic fate tests (e.g. OECD 308) lack environmental realism as they are conducted under dark conditions and in small-scale static systems, which can affect microbial diversity and functionality. In this study, water-sediment microflumes were used to investigate the impact of these deficiencies in environmental realism on the fate of the fungicide, isopyrazam. Although on a large-scale, these systems aimed to retain the key aspects of OECD 308 tests. Tests were carried out under both a non-UV light-dark cycle and continuous darkness and under both static and flowing water conditions, to investigate how light and water flow affect isopyrazam biodegradation pathways. In static systems, light treatment played a significant role, with faster dissipation in illuminated compared to dark microflumes (DT50s = 20.6 vs. 47.7 days). In flowing systems (DT50s = 16.8 and 15.3 days), light did not play a significant role in dissipation, which was comparable between the two light treatments, and faster than in dark static microflumes. Microbial phototroph biomass was significantly reduced by water flow in the illuminated systems, thereby reducing their contribution to dissipation. Comprehensive analysis of bacterial and eukaryotic community composition identified treatment specific changes following incubation, with light promoting relative abundance of Cyanobacteria and eukaryotic algae, and flow increasing relative abundance of fungi. We conclude that both water velocity and non-UV light increased isopyrazam dissipation, but the contribution of light depended on the flow conditions. These differences may have resulted from impacts on microbial communities and via mixing processes, particularly hyporheic exchange. Inclusion of both light and flow in studies could improve the extent they mimic natural environments and predict chemical environmental persistence, thus bridging the gap between laboratory and field studies.
| Item Type: | Journal Article | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Subjects: | Q Science > QD Chemistry S Agriculture > S Agriculture (General) |
||||||||
| Divisions: | Faculty of Science, Engineering and Medicine > Science > Life Sciences (2010- ) | ||||||||
| Library of Congress Subject Headings (LCSH): | Agricultural chemistry, Agricultural chemicals -- Environmental aspects, Bioremediation, Chemical tests and reagents, Chemicals -- Safety measures, Water -- Purification, Environmental management | ||||||||
| Journal or Publication Title: | Science of The Total Environment | ||||||||
| Publisher: | Elsevier | ||||||||
| ISSN: | 0048-9697 | ||||||||
| Official Date: | July 2023 | ||||||||
| Dates: |
|
||||||||
| Volume: | 880 | ||||||||
| Article Number: | 163282 | ||||||||
| DOI: | 10.1016/j.scitotenv.2023.163282 | ||||||||
| Status: | Peer Reviewed | ||||||||
| Publication Status: | Published | ||||||||
| Access rights to Published version: | Open Access (Creative Commons) | ||||||||
| Date of first compliant deposit: | 12 April 2023 | ||||||||
| Date of first compliant Open Access: | 13 April 2023 | ||||||||
| RIOXX Funder/Project Grant: |
|
Request changes or add full text files to a record
Repository staff actions (login required)
 |
View Item |
Downloads
Downloads per month over past year
