Author(s): Yueming Han; Chaomeng Dai

Linked Author(s):

Keywords: Polycyclic aromatic hydrocarbon Groundwater Peroxymonosulfate Photoresponsive surfactant AOPs

Abstract: Polycyclic aromatic hydrocarbons (PAHs) have posed serious risks to the groundwater environment. Due to their hydrophobicity, PAHs are difficult to be effectively removed from groundwater. In this study, a combination of a photosensitive surfactant (N1, N2-bis[4-[4-[ (4-butylphenyl) azo] phenoxy] butyl]-N1, N2-tetramethylethane-1,2- diammonium bromide, AzoPBT) with peroxymonosulfate (PMS) is developed to treat PAHs-contaminated groundwater. Naphthalene (Nap) and phenanthrene (Phe) are selected as targeted pollutants to investigate the reaction mechanism of the PMS/AzoPBT process. Singlet oxygen was found that contributed to the degradation of PAHs, which is evidenced by the quenching experiments and electron paramagnetic resonance spectroscopy (EPR). The positively charged micelles in the PMS/AzoPBT process escalate the removal of PAHs by electrostatically polymerizing Br- and HSO5- in the solution. Although increasing the concentration of AzoPBT in the system can significantly enhance the solubilization ability of the surfactant solution, the encapsulation of PAHs by micelles can “protect” PAHs, which hinders the removal of PAHs. The PMS/AzoPBT process can be applied in a wide range of pH values (from 3 to 11). In the process of recycling AzoPBT/PMS to remediate groundwater, PAHs can be completely removed in the first cycle, and 51.4 % of PAHs can be removed after four times of use. This study proposes a novel treatment technology of PAHs-contaminated groundwater, and provides insights into the removal mechanism of the PMS/AzoPBT process.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p1668-cd

Year: 2023