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oai:docta.ucm.es:20.500.14352/1299792026-01-14T00:49:16Zcom_20.500.14352_14col_20.500.14352_15

00925njm 22002777a 4500 dc Cotillas Soriano, Salvador author Domínguez Torre, Carmen María author Lorenzo Fernández, David author Sáez González, Patricia author Santos López, Aurora author Cano Lázaro, ELena author Fernández Cascán, Jesús author Herranz, Carlos author Net Ortega, Jorge author 2024-05-16 The LIFE SURFING Project was carried out at the Bailin Landfill in Sabiñánigo, Spain (2020-2022), applying Surfactant Enhanced Aquifer Remediation (SEAR) and In Situ Chemical Oxidation (S-ISCO) in a 60-meter test cell beneath the old landfill, to remediate a contaminated aquifer with dense non-aqueous phase liquid (DNAPL) from nearby lindane production. The project overcame traditional extraction limitations, successfully preventing groundwater pollution from reaching the river. In spring 2022, two SEAR interventions involved the injection of 9.3 m3 (SEAR-1) and 6 m3 (SEAR-2) of aqueous solutions containing 20 g/L of the non-ionic surfactant E-Mulse 3®, with bromide (around 150 mg/L) serving as a conservative tracer. 7.1 and 6.0 m3 were extracted in SEAR-1 and SEAR-2, respectively, recovered 60–70 % of the injected bromide and 30–40 % of the surfactant, confirming surfactant adsorption by the soil. Approximately 130 kg of DNAPL were removed, with over 90 % mobilized and 10 % solubilized. A surfactant-to-DNAPL recovery mass ratio of 2.6 was obtained, a successful value for a fractured aquifer. In September 2022, the S-ISCO phase entailed injecting 22 m3 of a solution containing persulfate (40 g/L), E-Mulse 3® (4 g/L), and NaOH (8.75 g/L) in pulses over 48 h, oxidizing around 20 kg of DNAPL and ensuring low toxicity levels after that. Preceding the SEAR and S-ISCO trials, 2020 and 2021 were dedicated to detailed groundwater flow characterizations, including hydrological and tracer studies. These preliminary investigations allowed the design of a barrier zone between 317 and 557 m from the test cell and the river, situated 900 m away. This zone, integrating alkali dosing, aeration, vapor extraction, and oxidant injection, effectively prevented the escape of fluids to the river. Neither surfactants nor contaminants were detected in river waters post-treatment. The absence of residual phase in test cell wells and reduction of chlorinated compound levels in groundwater were noticed till one year after S-ISCO. Jesús Fernández, David Lorenzo, Jorge Net, Elena Cano, Patricia Saez, Carlos Herranz, Carmen M. Domínguez, Salvador Cotillas, Aurora Santos, Sustainable lindane waste remediation: Surfactant-driven residual DNAPL extraction and oxidation in a real landfill (LIFE SURFING), Science of The Total Environment, Volume 934, 2024, 173260, ISSN 0048-9697, https://doi.org/10.1016/j.scitotenv.2024.173260. (https://www.sciencedirect.com/science/article/pii/S0048969724034077) 10.1016/j.scitotenv.2024.173260 https://hdl.handle.net/20.500.14352/129979 https://doi.org/10.1016/j.scitotenv.2024.173260 https://www.sciencedirect.com/science/article/pii/S0048969724034077 Sustainable lindane waste remediation: Surfactant-driven residual DNAPL extraction and oxidation in a real landfill (LIFE SURFING)