Decontamination of Pure and Ethanol/Gasoline-Contaminated Soil by Fenton-Like Process

de Souza, DanielaTidre; Benetti, CarolineNocêra; Sauer, Elenise; Paula, ViniciusC. S.; Freitas, AdrianeMartins; Tiburtius, ElaineR. L.

Decontamination of Pure and Ethanol/Gasoline-Contaminated Soil by Fenton-Like Process

2018

Soil contaminated by benzene, toluene, and xylene (BTX) is one of the biggest environmental problems, and it is estimated that the main source of contamination is due to fuel spills. Chemical oxidation has been considered as an alternative for removal of hydrocarbons from soil contaminated with gasoline. However, it is still necessary to study the effective capacity of these processes in the degradation and toxicity elimination of aromatic hydrocarbons, such as BTX. In this study, two different Fenton-like remediation techniques were investigated for the remediation of soil contaminated with BTX (Fe³⁺/H₂O₂ and H₂O₂ alone) and using two gasoline (pure and with ethanol). Results showed that both processes were efficient for the remediation of BTX. After 60 min of treatment using addition of Fe³⁺ or H₂O₂ alone, a high level of removal of BTX was observed (> 70%). However, lower rates of degradation were observed when the soil was contaminated with pure gasoline (> 40%) indicating that the effectiveness of system depends also on the characteristics of the gasoline. Phytotoxicity studies were carried out before and after treatment using Lactuca sativa seeds. Results showed that the intermediates formed after treatment affected the germination and root development of Lactuca sativa. The germination index (GI) observed was 0% for both processes. This shows that more toxic by-product compounds can be generated during remediation. For this reason, the treatment requires attention. Although the Fenton-like process might remove BTX from contaminated soil after 60 min of reaction, it was not sufficient to remove or eliminate the phytotoxicity.

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