Influence of Celery on the Remediation of PAHs-contaminated Farm Soil

ABSTRACT

Polycyclic aromatic hydrocarbons (PAHs) contamination has been considered as one of the major environmental concerns for farmland soil all over the world including China. Due to small per capita land area, to find crops or vegetable, which could not only degrade the PAHs contaminants but also would not concentrate PAHs, was particularly important. Celery was selected as the phytoremediator in this experiment, and the soil enzyme activity, PAHs-degrading microorganisms, and the speciation of PAHs in soil were studied. The results showed that celery could significantly enhance the remediation of PAHs compared with the controlled experiment after 90 days (p< 0.01), and the removal efficiency were 31.29%, 30.79%, and 50.21% in the soil, non-rhizosphere soil, and rhizosphere soil, respectively. The soil enzyme activity and PAHs-degrading microorganisms significantly increased in rhizosphere soil compared with non-rhizosphere soil (p< 0.05), and the bioaccessibility of PAHs in soil could have been enhanced in the presence of celery root exudates. Those would help the bioremediation of PAHs by soil microorganisms. Meanwhile, the concentration of PAHs in the edible portion of celery was only 17.13 ± 1.24 μg/kg, and the bioconcentration factors in the aboveground part of celery were only 0.025. This study provides a potential in-site farmland soil phytoremediation technology that could have practical utility.

KEYWORDS:

• Celery
• PAHs-contaminated farm soil
• soil enzyme activity
• PAHs-degrading microorganisms
• speciation
• rhizosphere

Acknowledgement

The authors thank the staff of Shenyang University Laboratory of Eco-Remediation and Resource Reuse for their support during field sampling, logistics, and laboratory analysis.

Competing financial interests

The authors declare no competing financial interests.

Author contributions

Conceived and designed the experiments: Hui Wang. Performed the experiments: Hui Wang, Yueming Zhao, Chunyue Liu, Xiaoxu Wang, Yingkui Du and Hao Wu. Analyzed the data: Hui Wang, Xuehao Zheng and Kunzhe Wang. Wrote the paper: Hui Wang, Qing Luo, and Muhammad Adeel.

Additional information

Funding

This study was financially supported by Liaoning province science and technology plan(20170540656), the National Natural Science Foundation of China (41807384), the China Postdoctoral Science Foundation funded project (2015M630304), Science and Technology Program of Shenyang City (F16-155-9-00, 17-180-9-00), and the Natural Science Foundation of Liaoning Province (20170520384);the National Basic Research Program of China (973 Program) [2014CB441106];