Remediation of 1-Nitropyrene in Soil: A Comparative Study with Pyrene

Nitrated polycyclic aromatic hydrocarbons ( n PAHs) are ubiquitous environmental pollutants, which exhibits higher toxicity than their corresponding parent PAHs ( p PAHs). Recent studies demonstrated that the n PAHs could represent major soil pollution, however the remediation of n PAHs has been rarely reported. In this study, biological, physical, and chemical methods have been applied to remove 1-nitropyrene, the model n PAH, in contaminated soil. A comparative study with pyrene has also been investigated and evaluated. The results suggest that the physical method with activated carbon is an efficient and economical approach, removing 88.1% and 78.0% of 1-nitropyrene and pyrene respectively, within one day. The zero-valent ion has a similar removal performance on 1-nitropyrene (83.1%), converting 1-nitropyrene to 1-aminopyrene in soil via chemical reduction and decreasing the mutagenicity and carcinogenicity of 1-nitropyrene. Biological remediation that employs scallion as a plant model can reduce 55.0% of 1-nitropyrene in soil (from 39.6 to 17.8 μg/kg), while 77.9% of pyrene can be removed by plant. This indicates that n PAHs might be more persistent than corresponding p PAHs in soil. It is anticipated that this study could draw public awareness of nitro-derivatives of p PAHs and provide remediation technologies of carcinogenic n PAHs in soil.