## 3 Artificial Intervention in the Degradation of Antibiotics
### Ionizing Radiation Degradation  
Ionizing radiation refers to radiation--such as electromagnetic waves or particle streams--that possesses sufficient energy to remove electrons from atoms or molecules in a substance, thereby generating ions. Examples of ionizing radiation include gamma rays, X-rays, and electron beams. This type of radiation is increasingly recognized as a promising alternative for degrading various toxic organic pollutants, including chlorophenols [107], nitrophenols [108], and antibiotics [109], which has attracted significant attention in many countries. The advantages of ionizing radiation technology include the absence of the need to add any chemical substances, an insensitivity to color and suspended particles, and a good permeability in aqueous matrices. Additionally, this technology can degrade difficult-to-degrade compounds in situ through reactive species generated during the water radiolysis process [110]. Radiolytic degradation primarily involves the production of strong oxidizing agents (\(\bullet\)OH) and strong reducing agents (e-aq, H\(\bullet\)) in water under ionizing radiation, which can effectively eliminate a wide range of pollutants. Currently, research is being conducted on the use of gamma rays or electron beam irradiation as advanced oxidation processes to remove antibiotics. For instance, [PERSON] et al. studied the degradation effects of \(\gamma\)-rays on amoxicillin, doxycycline, and ciprofloxacin. They found that at an initial concentration of 50 uM, a radiation dose of 7 kGy could achieve a removal rate exceeding 90%, with the degradation process adhering to a pseudo-first-order kinetic model [111]. Similarly, [PERSON] et al. employed 30 kGy electron beams to degrade antibiotic residues in medical infusion bottles, achieving degradation rates of 97.02%, 97.61%, and 96.87% for amoxicillin, ofloxacin, and cephalexin, respectively [83]. Additionally, [PERSON] et al. degraded ciprofloxacin (initial concentration of 20 mg/L) through \(\gamma\)-irradiation, achieving a removal rate of 88.35% at a dose of 400 Gy, and noted that lower concentration antibiotics were more readily degraded [112]. These studies demonstrate that ionizing radiation possesses a significant degradation capability for various types of antibiotics, with the degradation efficiency closely linked to the irradiation dose and initial concentration. The efficiency of ionizing radiation in degrading antibiotics is influenced by various factors, including pH, inorganic anions, and organic matter. The pH level affects the degradation process by altering the generation ratio of free radicals. For instance, [PERSON] et al. found that the degradation rate of sulfanilamide under acidic conditions at a pH of 3 (93.11%) was higher than that under alkaline conditions at a pH of 11 (87.30%), which is attributed to the more favorable generation of hydroxyl radicals (\(\bullet\)OH) in acidic environments [113]. Conversely, research by [PERSON] et al. indicated that alkaline conditions at a pH of 9 are more conducive to the electron beam degradation of antibiotics such as amoxicillin, suggesting that the optimal pH range for different antibiotics may vary based on their molecular structures [83]. Additionally, inorganic anions like carbonate (CO\({}_{3}\)\({}^{2-}\)) and nitrate (NO\({}_{3}\)\({}^{-}\)), as well as organic matter such as humic acid, can compete with target antibiotics for free radicals, thereby inhibiting the degradation efficiency. For example, [PERSON] et al. noted that the presence of CO\({}_{3}\)\({}^{2-}\) and NO\({}_{3}\)\({}^{-}\) significantly reduced the degradation rate of antibiotics [111], while humic acid decreased the removal rate of ciprofloxacin from 99.6% to 47.2% by consuming \(\bullet\)OH [112]. Ionizing radiation technology has gradually transitioned from laboratory research to practical applications.