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Chokejaroenrat C, Sakulthaew C, Chantakulvanich S, Angkaew A, Teingtham K, Phansak P, Poompoung T, Snow DD, Harris CE, Comfort SD. Enhanced degradation of herbicides in groundwater using sulfur-containing reductants and spinel zinc ferrite activated persulfate. Sci Total Environ 2023; 892:164652. [PMID: 37295514 DOI: 10.1016/j.scitotenv.2023.164652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 06/01/2023] [Accepted: 06/01/2023] [Indexed: 06/12/2023]
Abstract
A challenge to successfully implementing an injection-based remedial treatment in aquifers is to ensure that the oxidative reaction is efficient and lasts long enough to contact the contaminated plume. Our objective was to determine the efficacy of zinc ferrite nanocomposites (ZnFe2O4) and sulfur-containing reductants (SCR) (i.e., dithionite; DTN and bisulfite; BS) to co-activate persulfate (S2O82-; PS) and treat herbicide-contaminated water. We also evaluated the ecotoxicity of the treated water. While both SCRs delivered excellent PS activation in a 1:0.4 ratio (PS:SCR), the reaction was relatively short-lived. By including ZnFe2O4 in the PS/BS or PS/DTN activations, herbicide degradation rates dramatically increased by factors of 2.5 to 11.3. This was due to the SO4- and OH reactive radical species that formed. Radical scavenging experiments and ZnFe2O4 XPS spectra results revealed that SO4- was the dominant reactive species that originated from S(IV)/PS activation in solution and from the Fe(II)/PS activation that occurred on the ZnFe2O4 surface. Based on liquid chromatography mass spectrometry (LC-MS), atrazine and alachlor degradation pathways are proposed that involve both dehydration and hydroxylation. In 1-D column experiments, five different treatment scenarios were run using 14C-labeled and unlabeled atrazine, and 3H2O to quantify changes in breakthrough curves. Our results confirmed that ZnFe2O4 successfully prolonged the PS oxidative treatment despite the SCR being completely dissociated. Toxicity testing showed treated 14C-atrazine was more biodegradable than the parent compound in soil microcosms. Post-treatment water (25 %, v/v) also had less impact on both Zea Mays L. and Vigna radiata L. seedling growth, but more impact on root anatomies, while ≤4 % of the treated water started to exert cytotoxicity (<80 % viability) on ELT3 cell lines. Overall, the findings confirm that ZnFe2O4/SCR/PS reaction is efficient and relatively longer lasting in treating herbicide-contaminated groundwater.
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Affiliation(s)
- Chanat Chokejaroenrat
- Department of Environmental Technology and Management, Faculty of Environment, Kasetsart University, Bangkok 10900, Thailand.
| | - Chainarong Sakulthaew
- Department of Veterinary Technology, Faculty of Veterinary Technology, Kasetsart University, Bangkok 10900, Thailand.
| | - Sirimon Chantakulvanich
- Department of Environmental Technology and Management, Faculty of Environment, Kasetsart University, Bangkok 10900, Thailand
| | - Athaphon Angkaew
- Department of Environmental Technology and Management, Faculty of Environment, Kasetsart University, Bangkok 10900, Thailand
| | - Kanokwan Teingtham
- Department of Agronomy, Faculty of Agriculture at Kamphaeng Saen, Kasetsart University, Nakhon Pathom 73140, Thailand.
| | - Piyaporn Phansak
- Division of Biology, Faculty of Science, Nakhon Phanom University, Nakhon Phanom 48000, Thailand.
| | - Thapanee Poompoung
- Department of Veterinary Technology, Faculty of Veterinary Technology, Kasetsart University, Bangkok 10900, Thailand.
| | - Daniel D Snow
- Water Sciences Laboratory, University of Nebraska-Lincoln, Lincoln, NE 68583-0844, USA.
| | - Clifford E Harris
- Department of Chemistry and Biochemistry, Albion College, Albion, MI 49224, USA.
| | - Steve D Comfort
- School of Natural Resources, University of Nebraska, Lincoln, NE 68583-0915, USA.
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