Sulfidated nano zerovalent iron (S-nZVI) for in situ treatment of chlorinated solvents: A field study
| Autor: | Ariel Nunez Garcia, Hardiljeet K. Boparai, C. M. Kocur, Ahmed I.A. Chowdhury, Barbara Sherwood Lollar, Elodie Passeport, Jose E. Herrera, Denis M. O'Carroll, Leanne M. Austrins, Cjestmir V. de Boer |
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| Rok vydání: | 2020 |
| Předmět: |
Environmental Engineering
Halogenation Iron Water Wells 0208 environmental biotechnology Sulfidation 02 engineering and technology 010501 environmental sciences 01 natural sciences Chloride Vinyl chloride chemistry.chemical_compound Hydrogenolysis medicine Groundwater Waste Management and Disposal Dissolution 0105 earth and related environmental sciences Water Science and Technology Civil and Structural Engineering Zerovalent iron Ecological Modeling Contamination Pollution 6. Clean water 020801 environmental engineering Dilution chemistry 13. Climate action Carboxymethylcellulose Sodium Environmental chemistry Solvents Water Pollutants Chemical medicine.drug |
| Zdroj: | Water Research. 174:115594 |
| ISSN: | 0043-1354 |
| DOI: | 10.1016/j.watres.2020.115594 |
| Popis: | Sulfidated nano zerovalent iron (S-nZVI), stabilized with carboxymethyl cellulose (CMC), was successfully synthesized on site and injected into the subsurface at a site contaminated with a broad range of chlorinated volatile organic compounds (cVOCs). Transport of CMC-S-nZVI to the monitoring wells, both downgradient and upgradient, resulted in a significant decrease in concentrations of aqueous-phase cVOCs. Short-term (0–17 days) total boron and chloride measurements indicated dilution and displacement in these wells. Importantly however, compound specific isotope analysis (CSIA), changes in concentrations of intermediates, and increase in ethene concentrations confirmed dechlorination of cVOCs. Dissolution from the DNAPL pool into the aqueous phase at the deepest levels (4.0–4.5 m bgs) was identifiable from the increased cVOCs concentrations during long-term monitoring. However, at the uppermost levels (∼1.5 m above the source zone) a contrasting trend was observed indicating successful dechlorination. Changes in cVOCs concentrations and CSIA data suggest both sequential hydrogenolysis as well as reductive β-elimination as the possible transformation mechanisms during the short-term abiotic and long-term biotic dechlorination. One of the most positive outcomes of this CMC-S-nZVI field treatment is the non-accumulation of lower chlorinated VOCs, particularly vinyl chloride. Post-treatment soil cores also revealed significant decreases in cVOCs concentrations throughout the targeted treatment zones. Results from this field study show that sulfidation is a suitable amendment for developing more efficient nZVI-based in situ remediation technologies. |
| Databáze: | OpenAIRE |
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