Polycyclic aromatic hydrocarbon removal from subsurface soil mediated by bacteria and archaea under methanogenic conditions: Performance and mechanisms

Yaling Gou; Yun Song; Sucai Yang; Yan Yang; Yanan Cheng; Jiabin Li; Tengfei Zhang; Yanjun Cheng; Hongqi Wang

doi:10.1016/j.envpol.2022.120023

Polycyclic aromatic hydrocarbon removal from subsurface soil mediated by bacteria and archaea under methanogenic conditions: Performance and mechanisms

Environ Pollut. 2022 Nov 15:313:120023. doi: 10.1016/j.envpol.2022.120023. Epub 2022 Aug 28.

Authors

Yaling Gou¹, Yun Song², Sucai Yang², Yan Yang², Yanan Cheng², Jiabin Li², Tengfei Zhang², Yanjun Cheng², Hongqi Wang³

Affiliations

¹ College of Water Sciences, Beijing Normal University, Beijing, 100875, China; Beijing Key Laboratory of Remediation of Industrial Pollution Sites, Institute of Resources and Environment, Beijing Academy of Science and Technology, Beijing, 100089, China.
² Beijing Key Laboratory of Remediation of Industrial Pollution Sites, Institute of Resources and Environment, Beijing Academy of Science and Technology, Beijing, 100089, China.
³ College of Water Sciences, Beijing Normal University, Beijing, 100875, China. Electronic address: amba@bnu.edu.cn.

PMID: 36030953
DOI: 10.1016/j.envpol.2022.120023

Abstract

In situ anoxic bioremediation is an easy-to-use technology to remediate polycyclic aromatic hydrocarbon (PAH)-contaminated soil. Degradation of PAHs mediated by soil bacteria and archaea using CO₂ as the electron acceptor is an important process for eliminating PAHs under methanogenic conditions; however, knowledge of the performance and mechanisms involved is poorly unveiled. In this study, the effectiveness and efficiency of NaHCO₃ (CO₂) as an electron acceptor to stimulate the degradation of PAHs by bacteria and archaea in highly contaminated soil were investigated. The results showed that CO₂ addition (EC2000) promoted PAH degradation compared to soil without added CO₂ (EC0), with 4.18%, 9.01%-8.05%, and 6.19%-12.45% increases for 2-, 3- and 4-ring PAHs after 250 days of incubation, respectively. Soil bacterial abundances increased with increasing incubation time, especially for EC2000 (2.90 × 10⁸ g^-1 soil higher than EC0, p < 0.05). Different succession patterns of the soil bacterial and archaeal communities during PAH degradation were observed. According to the PCoA and ANOSIM results, the soil bacterial communities were greatly (ANOSIM: R = 0.7232, P = 0.001) impacted by electron acceptors, whereas significant differences in the archaeal communities were not observed (ANOSIM: R = 0.553, P = 0.001). Soil bacterial and archaeal co-occurrence network analyses showed that positive correlations outnumbered the negative correlations throughout the incubation period for both treatments (e.g., EC0 and EC2000), suggesting the prevalence of coexistence/cooperation within and between these two domains rather than competition. The higher complexity, connectance, edge, and node numbers in EC2000 revealed stronger linkage and a more stable co-occurrence network compared to EC0. The results of this study could improve the knowledge on the removal of PAHs and the responses of soil bacteria and archaea to CO₂ application, as well as a scientific basis for the in situ anoxic bioremediation of PAH-contaminated industrial sites.

Keywords: Biostimulation; Methanogenic condition; Microbial co-occurrence network; Polycyclic aromatic hydrocarbons; Soil bacteria and archaea.

MeSH terms

Archaea / metabolism
Bacteria / metabolism
Biodegradation, Environmental
Carbon Dioxide / metabolism
Polycyclic Aromatic Hydrocarbons* / analysis
Soil
Soil Microbiology
Soil Pollutants* / analysis

Substances

Polycyclic Aromatic Hydrocarbons
Soil
Soil Pollutants
Carbon Dioxide