The application of exogenous Se improved the remediation efficiency of Lolium multiflorum Lam grown in nonylphenol-Cd Co-contaminated soil

Abstract

Nonylphenol (NP) and cadmium (Cd), very toxic to microorganisms, plants, and animals, are often detected simultaneously in soil and water. Selenium (Se) is important to microorganisms and plants. A pot experiment was carried out to explore the effect of Se on the efficiency of ryegrass in the remediation of NP-Cd co-contaminated soil. The removal rate of soil NP and Cd increased by 6.2 % and 30.8 %, respectively, with the application of exogenous Se in NP-contaminated soil (50 mg·kg−1). The selenium significantly increased the catalase activity (11.5–24.5%), but decreased the activities of acid phosphatase (5.5–9.0 %), invertase (19.8–22.5 %), and urease (11.1–18.4 %) in NP contaminated soil (50 mg·kg−1) (p＜0.05). The selenium also increased the relative abundance of beneficial bacteria, including Massilia, Burkholderiaceae, Micrococcales, and Sphingomonas in the NP-Cd co-contaminated soil. These bacteria are closely related to Cd and NP pollution remediation. In summary, applying Se to the contaminated soil effectively improved the efficiency of the phytoremediation of NP and Cd, and also increased the relative abundance and diversity of microorganisms in the NP-Cd co-contaminated soil. These findings can attract practical interest in phytoremediation measures of organic and heavy metals co-contaminated soil.