Combined phyto-microbial-electrochemical system enhanced the removal of petroleum hydrocarbons from soil: A profundity remediation strategy

• Published in: Journal of hazardous materials 2021-10, Vol.420, p.126592, Article 126592
• Main Authors: Zhang, Xiaolin, Li, Ruixiang, Song, Jintong, Ren, Yuanyuan, Luo, Xi, Li, Yi, Li, Xiaojing, Li, Tian, Wang, Xin, Zhou, Qixing
• Format: Article
• Language: English
• Subjects: Metabolism analysis; Microbial interaction; Petroleum hydrocarbon degradation; Phytoremediation; Soil microbial electrochemical system
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2021.126592

The soil contaminated by petroleum hydrocarbons has been a global environmental problem and its remediation is urgent. A combined phyto-microbial-electrochemical system (PMES) was constructed to repair the oil-contaminated soil in this study. During the 42-day operation time, a total petroleum hydrocarbons (TPHs) of 18.0 ± 3.0% were removed from PMES, which increased by 414% compared with the control group (CK1). The supervision of physicochemical properties of pore water in soil exhibited an enhanced microbial consumption of the total organic carbon (TOC) and N source under the applied potential with the generation of bio-current. The microbial succession indicated that the Dietzia, Georgenia and Malbranchea possibly participated in the degradation and current output in PMES. And a collaborative network of potential degrading microorganisms including unclassified norank_f__JG30-KF-CM45 (in Chloroflexi), Dietzia and Malbranchea was discovered in PMES. While the functional communities of microorganism were re-enriched with the reconstructed interactions in the system which was started with the sterilized soil (S+MEC). The superiority of TPHs degradation in S+MEC compared to P + CK2 (removing the electrochemical effect relative to CK1) revealed the key role of external potential in regulating the degradation microflora. The study provided a strategy of the potential regulated phyto-microbial interaction for the removal of TPHs. [Display omitted] •The first attempt of combined phyto-microbial-electrochemical system in soil.•The removal of TPHs using PMES was 414% higher than that in control (CK1).•The biocurrent averaged on 0.45 ± 0.12 mA was generated from PMES on day 10.•Microbial communities were reallocated in the constructed composite system.•Metabolic networks of rhizosphere microflora were shaped in PMES.