Photochemical degradation in natural attenuation of characteristics of petroleum hydrocarbons (C10-C40) in crude oil polluted soil by simulated long term solar irradiation

Xiuxiu Yan; Jing An; Yanzi Zhang; Shuhe Wei; Wenxiang He; Qixing Zhou

doi:10.1016/j.jhazmat.2023.132259

Photochemical degradation in natural attenuation of characteristics of petroleum hydrocarbons (C₁₀-C₄₀) in crude oil polluted soil by simulated long term solar irradiation

J Hazard Mater. 2023 Oct 15:460:132259. doi: 10.1016/j.jhazmat.2023.132259. Epub 2023 Aug 19.

Authors

Xiuxiu Yan¹, Jing An², Yanzi Zhang³, Shuhe Wei³, Wenxiang He⁴, Qixing Zhou⁵

Affiliations

¹ Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; University of Chinese Academy of Sciences, Beijing 100049, China.
² Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; National-Local Joint Engineering Laboratory of Contaminated Soil Remediation by Bio-physicochemical Synergistic Process, Shenyang 110142, China. Electronic address: anjing@iae.ac.cn.
³ Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
⁴ College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, China.
⁵ Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.

PMID: 37633018
DOI: 10.1016/j.jhazmat.2023.132259

Abstract

Photodegradation process plays an important role in the natural attenuation of petroleum hydrocarbons (PHs) in oil contaminated soil. The photodegradation characteristics of PHs (C₁₀-C₄₀) in topsoil of crude oil contaminated soil irradiated by simulated sunlight in 280 d without microbial action were investigated. The results showed that photodegradation rate of PHs was increased with increasing the light intensity and decreased with increasing the initial concentration of PHs. Moreover, the photodegradation capacity of tested PHs was relevant to the length of carbon chain. The photodegradation rates of C₁₀-C₂₀ were higher than that of C₂₁-C₄₀ in photoperiod. C₂₁-C₄₀ showed an obvious trend of photodegradation after 56 d, although their photodegradation rates were less than 20% at the early stage. And, the redundancy analysis indicated that lighting time was the primary factor for photodegradation of PHs under abiotic conditions. The photodegradation rate was well interpreted by a two-stage, first-order kinetic law with a faster initial photolysis rate. The EPR spectrums showed that simulated solar irradiation accelerated the generation of superoxide radicals, which could react with PHs in soil. Also, the function groups in PHs polluted soil were changed after light exposure, which might imply the possible photodegradation pathway of PHs.

Keywords: Natural attenuation; Normal alkanes; Petroleum-polluted soil; Photochemical degradation; Superoxide radicals.