Remediation of hydrocarbon–heavy metal co-contaminated soil by electrokinetics combined with biostimulation

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2018-12, Vol.353, p.410-418
• Main Authors: Ma, Yongsong, Li, Xi, Mao, Hongmin, Wang, Bing, Wang, Peijie
• Format: Article
• Language: English
• Subjects: Bioeletrokinetic; Ecotoxicity; Hydrocarbon; Nickel; Soil
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2018.07.131

•An enhanced BioEK remediation was developed to decontaminate co-contaminated soil.•Electro-bioremediation achieved 77.4% hydrocarbon degradation and 58.5% Ni removal.•Selective membranes were successfully used to control soil pH stability.•BioEK remediation improved biodegradation and reduced biological toxicity.•Citrobacter sp. promoted metal immobilization (e.g., increase in residual Ni). Successful remediation of organics and heavy metals compound pollution is challenging, and their removal using conventional techniques is often difficult. This study developed an enhanced electrokinetics technology to decontaminate a hydrocarbon–heavy metal co-contaminated soil by applying biostimulation and selective membranes (cationic and anionic). A 30-day experiment was conducted in the laboratory to remediate the soil co-contaminated with total petroleum hydrocarbon (TPH) (9075 mg/kg) and Ni (446.6 mg/kg). The results demonstrated that the addition of anion- and cation-exchange membranes maintained soil pH stability. BioEK remediation under pH control improved microbial growth, microbial degradation of petroleum and reduced biological toxicity. Microbial action immobilized metals (e.g., reduction in exchangeable Ni and the increase in residual Ni). The degradation rate of TPH in contaminated soil was linearly correlated with the increase in TPH degradation population (P