Bioremediation of Hydrocarbon-Polluted Soil: Evaluation of Different Operative Parameters

Abstract

The bioremediation of soils polluted with hydrocarbons demonstrated to be a simple and cheap technique, even if it needs a long time. The current paper shows the application of statistical analysis, based on two factors involved in the biological process at several levels. We focus on the Design of Experiments (DOE) to determine the number and kind of experimental runs, whereas the use of the categorical factors has not been widely exploited up to now. This method is especially useful to analyze factors with levels constituted by categories and define the interaction effects. Particularly, we focused on the statistical analysis of (1) experimental runs carried out at laboratory scale (test M, in microcosm), on soil polluted with diesel oil, and (2) bench scale runs (test B, in biopile), on refinery oil sludge mixed with industrial or agricultural biodegradable wastes. Finally, the main purpose was to identify the factor’s significance in both the tests and their potential interactions, by applying the analysis of variance (ANOVA). The results demonstrate the robustness of the statistical method and its quality, especially when at least one of the factors cannot be defined with a numerical value.

Bench-Scale Biopile Hydrocarbons Removal Optimization Using the Response Surface Methodology and Simultaneous Optimization

“…It was sieved using an industrial mesh for particles smaller than 4,75 mm, according to Cuban standards based on ASTM norms (ASTM International, 2002. For the mixture of texturizers, the best candidates for different treatments were selected, which had been tested in previous stages of the BIOPILA project (Casals et al, 2020;Gutiérrez et al, 2020;Castro et al, 2022c;Castro et al, 2022d). On the one hand, the candidate which reported the lowest TPH concentrations at 240 days, the highest degradation kinetic rate, and the shortest half-life (t 1/2 ) among all the considered treatments was used.…”

“…The BIOPILA project aims to address an innovative and resilient technique to cope with the environmental problem of soil polluted with hydrocarbons in Cuba, specifically with the residues generated by the local industry which remain confined without a solution (Castro et al, 2022a). Previous research carried out within the framework of the aforementioned project has shown, at the bench scale, the relevance of biopile ecotechnology for the degradation of soils polluted with hydrocarbons (Gutiérrez et al, 2021;Castro et al, 2022b, Gutiérrez, et al, 2022Castro et al, 2022c). Significant removal rates were reported for oils and grease concentrations (between 50,05 and 66,08%).…”

Indigenous oil-degrading bacteria more efficient in soil bioremediation than microbial consortium and active even in super oil-saturated soils

“…It is noteworthy to point out that most of the bioremediation studies used low concentrations of crude oil reaching 7% (Hesnawi and Mogadami, 2013 ; Qiao et al, 2013 ; Goudarztalejerdi et al, 2015 ; Siles and Margesin, 2018 ; Castro Rodríguez et al, 2022 ). Vasilyeva et al ( 2020 ) used oil concentrations of 5–15% and reported that bioremediation can be applied on oil concentrations less than 5% only due to toxicity.…”