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N-doped graphite carbon sphere coated cobalt nanoparticle catalyst (Co@C-N-900), prepared by solvothermal-calcination method, is applied to activate peroxymonosulfate (PMS) for bisphenol A (BPA) elimination. The outcomes demonstrate that the Co@C-N-900 could effectively activate PMS, thereby causing efficient removal of BPA in water. In addition, the Co@C-N-900/PMS system also has the advantages of low metal leaching, applicability in high salinity environments, good selectivity and stability. Further investigations using electron paramagnetic resonance, chronoamperometry, and quenching experiments demonstrated that the Co@C-N-900/PMS system is a typical non-radical route with singlet oxygen (1O2) as the main reactive oxygen species (ROS). Density functional theory calculations (DFT) indicate that N-doping can effectively regulate the charge distribution on the catalyst surface, generating acidic/alkaline sites favorable for PMS adsorption and activation. Furthermore, it also can enhance the interaction and charge transfer capacity between the Co@C-N-900 and PMS. Lastly, LC-QTOF-MS/MS analysis revealed two possible BPA degradation pathways: (1) 1O2attacked the isopropyl group in BPA between the two phenyl groups, causing β-scission to occur. (2) Following the oxidation of the hydroxyl group in the aromatic ring of BPA, 1O2could cause further β-scission. The preparation Co@C-N-900 catalyst is a very promising catalyst, which would offer a workable remedy for treating water pollution.

In order to effectively improve the horizontal bearing capacity of pile foundations, this study proposes post-expanded arm grouting technology and associated pile foundations. The horizontal bearing characteristic of the post-expanded arm grouting pile was explored through model tests. The test results indicate that the post-expanded arm grouting pile can increase the contact area between the pile and soil, and can improve the strength of the soil. The horizontal bearing capacity of the post-expanded arm grouting pile was approximately 3 times that of the conventional pile. It also shows that the larger the plate diameter ratio or grouting volume, the higher the horizontal bearing capacity of the post-expanded arm grouting pile. The maximum bending moment of the post-expanded arm grouting pile was located at the pile plate, and the displacement zero point of the new pile was higher than that of the conventional pile. The soil resistance at the pile plate was significantly higher than that of conventional piles, indicating that the pile plate effectively enhances the soil resistance. The improved p-ycurve model and horizontal bearing capacity calculation method for the post-expanded arm grouting pile were proposed by considering the pile plate diameter factor. This method was finally verified by experimental results. The results of this study can provide a reference for calculating the horizontal bearing capacity of the post-expanded arm grouting pile.