Use of Liquid Industrial By-Products as Biostimulants in the Remediation of Hydrocarbon-Contaminated Soils

Emilio Ritoré, Carmen Arnaiz (), José Morillo, Agata Egea-Corbacho () and José Usero
Additional contact information
Emilio Ritoré: Department of Chemical and Environmental Engineering, Escuela Técnica Superior de Ingeniería, Universidad de Sevilla, Camino de los Descubrimientos, 41092 Seville, Spain
Carmen Arnaiz: Department of Chemical and Environmental Engineering, Escuela Técnica Superior de Ingeniería, Universidad de Sevilla, Camino de los Descubrimientos, 41092 Seville, Spain
José Morillo: Department of Chemical and Environmental Engineering, Escuela Técnica Superior de Ingeniería, Universidad de Sevilla, Camino de los Descubrimientos, 41092 Seville, Spain
Agata Egea-Corbacho: Department of Chemical and Environmental Engineering, Escuela Técnica Superior de Ingeniería, Universidad de Sevilla, Camino de los Descubrimientos, 41092 Seville, Spain
José Usero: Department of Chemical and Environmental Engineering, Escuela Técnica Superior de Ingeniería, Universidad de Sevilla, Camino de los Descubrimientos, 41092 Seville, Spain

Clean Technol., 2025, vol. 7, issue 4, 1-17

Abstract: Soil contamination by petroleum hydrocarbons represents a significant environmental challenge, especially in industrial and urban areas. This study evaluates the use of three industrial liquid by-products—sludge dewatering sidestream (SD), leftover yeast (LY), and secondary clarifier effluent (SC)—as biostimulant agents for the bioremediation of soils contaminated with gasoline and diesel mixtures. The novelty lies in applying these waste streams within a circular economy framework, with the added advantage that they can be injected directly into the subsurface. Microcosm tests were conducted over 20 weeks, analyzing the degradation of total petroleum hydrocarbons (TPHs) and their aliphatic and aromatic fractions using gas chromatography. The results show that all by-products improved biodegradation compared to natural attenuation. LY was the most effective, achieving 73.2% TPH removal, followed by SD (70.6%) and SC (65.4%). The greatest degradation was observed in short-chain hydrocarbons (C6–C16), while compounds with higher molecular weight (C21–C35) were more recalcitrant. In addition, aliphatic hydrocarbons showed greater degradability than aromatics in heavy fractions. Kinetic analysis revealed that the second-order model best fitted the experimental data, with higher correlation coefficients (R 2 ) and more representative half-lives. Catalase enzyme activity also increased in soils treated with LY and SD, indicating higher microbial activity.

Keywords: aliphatic hydrocarbons; aromatic hydrocarbons; circular economy; resources recovery; soil bioremediation (search for similar items in EconPapers)
JEL-codes: Q2 Q3 Q4 Q5 (search for similar items in EconPapers)
Date: 2025
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2571-8797/7/4/114/pdf (application/pdf)
https://www.mdpi.com/2571-8797/7/4/114/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jcltec:v:7:y:2025:i:4:p:114-:d:1815973

Access Statistics for this article

Clean Technol. is currently edited by Ms. Shary Song

More articles in Clean Technol. from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().