| Title: | Sulfidated nano zerovalent iron (S-nZVI) for in situ treatment of chlorinated solvents: A field study |
| Author(s): | Nunez Garcia A; Boparai HK; Chowdhury AIA; de Boer CV; Kocur CMD; Passeport E; Sherwood Lollar B; Austrins LM; Herrera J; O'Carroll DM; |
| Address: | "Department of Civil and Environmental Engineering, Western University, 1151 Richmond Rd., London, Ontario, N6A 5B8, Canada. Department of Civil and Environmental Engineering, Western University, 1151 Richmond Rd., London, Ontario, N6A 5B8, Canada; Department of Civil and Mineral Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario, M5S 1A4, Canada. Department of Civil and Environmental Engineering, Western University, 1151 Richmond Rd., London, Ontario, N6A 5B8, Canada; Institute of Water and Flood Management, Bangladesh University of Engineering and Technology, Dhaka, Bangladesh. Department of Civil and Environmental Engineering, Western University, 1151 Richmond Rd., London, Ontario, N6A 5B8, Canada; Netherlands Organization for Applied Research, TNO, Princetonlaan 6, 3584, CB, Utrecht, the Netherlands. Department of Civil and Environmental Engineering, Western University, 1151 Richmond Rd., London, Ontario, N6A 5B8, Canada; OHSU-PSU School of Public Health, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA. Department of Civil and Mineral Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario, M5S 1A4, Canada; Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario, M5S 3E5, Canada. Department of Earth Sciences, University of Toronto, 22 Russell Street, Toronto, Ontario, M5S 3B1, Canada. Arcadis, 28550 Cabot Dr #500, Novi, 48377, MI, USA. Department of Chemical and Biochemical Engineering, Western University, 1151 Richmond Rd., London, Ontario, N6A 5B8, Canada. Department of Civil and Environmental Engineering, Western University, 1151 Richmond Rd., London, Ontario, N6A 5B8, Canada; School of Civil and Environmental Engineering, Water Research Centre, University of New South Wales, Sydney, NSW, 2052, Australia. Electronic address: d.ocarroll@unsw.edu.au" |
| DOI: | 10.1016/j.watres.2020.115594 |
| ISSN/ISBN: | 1879-2448 (Electronic) 0043-1354 (Linking) |
| Abstract: | "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 ( approximately 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 beta-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" |
| Keywords: | "Carboxymethylcellulose Sodium *Groundwater Halogenation Iron Solvents *Water Pollutants, Chemical Water Wells Chlorinated VOCs Dithionite Groundwater In situ remediation Nano zerovalent iron Sulfidation;" |
| Notes: | "MedlineNunez Garcia, Ariel Boparai, Hardiljeet K Chowdhury, Ahmed I A de Boer, Cjestmir V Kocur, Chris M D Passeport, Elodie Sherwood Lollar, Barbara Austrins, Leanne M Herrera, Jose O'Carroll, Denis M eng England 2020/02/25 Water Res. 2020 May 1; 174:115594. doi: 10.1016/j.watres.2020.115594. Epub 2020 Feb 7" |
