Effects of polycyclic aromatic hydrocarbons (PAHs) from different sources on soil enzymes and microorganisms of Malus prunifolia var. Ringo

ABSTRACT

The main components of polycyclic aromatic hydrocarbons (PAHs) and the degree of contamination of soil with different oils (gasoline, diesel oil, and lubricating oil) were examined. Malus prunifolia var. Ringo was planted in soil contaminated by gasoline, diesel oil, or lubricating oil with three different concentrations which were low concentration (0.1 g kg⁻¹), medium concentration (0.2 g kg⁻¹), and high concentration (0.5 g kg⁻¹) in April 2016. The changes in PAH contents and soil index in the soil were measured from July to September 2016. It showed that more naphthalene, anthracene, phenanthrene, fluorene, and flexion were detected in the three oil treatments. From July to September, three high-concentration oil treatments had inhibited soil urease activity in soil significantly except the diesel oil treatment with high concentration in August. The diesel and lubricating oil treatments had inhibited phosphatase and invertase activities in soil significantly. Three oil treatments inhibited the number of bacteria significantly in July. The total number of bacteria and fungi was highest in gasoline, and the total number of actinomycetes was highest in lubricating oil. The three oils affected the soil enzyme activity and the number of soil microorganisms and caused some damage to the soil ecological environment.

KEYWORDS:

• Polycyclic aromatic hydrocarbons
• Malus prunifolia var. Ringo
• soil enzyme activity
• soil microorganisms
• soil ecological environment

Acknowledgements

We would like to thank LetPub (www.letpub.com) for providing linguistic assistance during the preparation of this manuscript. The research was supported by Fruit innovation team project of Shandong Province, China (SDAIT-06-07), Agro-Industry Research and Development Special Fund of China (CARS-28), National Science and Technology Infrastructure Program, China (2014BAD16B02), and Key Technology Research and Development Program of Shandong, China (2018GNC113019).

Disclosure statement

The authors have no conflict of interest to declare.

Author contributions statement

Yunfei Mao, Jin Xu, Yanli Hu and Xiang Shen planned and designed the research. Yunfei Mao, Lulu Zhang, Yunyun Wang, Lu Yang, Yijun Yin, Xiafei Su, Yeping Liu, Huiling Pang, Jin Xu performed experiments, conducted fieldwork, analyzed data, etc. Yunfei Mao, Jin Xu, Yanli Hu and Xiang Shen wrote the manuscript. Every author contributed equally.

Additional information

Funding

This work was supported by the Fruit innovation team project of Shandong Province, China [SDAIT-06-07]; Agro-Industry Research and Development Special Fund of China [CARS-28]; National Science and Technology Infrastructure Program, China [2014BAD16B02]; Key Technology Research and Development Program of Shandong, China [2018GNC113019].