College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, Jiangsu, People's Republic of China.
College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, Jiangsu, People's Republic of China.
J Hazard Mater. 2020 Jun 5;391:122229. doi: 10.1016/j.jhazmat.2020.122229. Epub 2020 Feb 4.
Developing advanced treatment methods to minimize the release of emerging contaminants to natural water has become a matter of considerable interest. Sono-Fenton process was investigated to degrade bisphenol A (BPA) and sulfadiazine (SDZ). The HO generated in situ was used as the exclusive source. Results showed that, the 400 kHz ultrasound is more efficient in creating homogeneous sono-Fenton than the 20 kHz apparatus due to the higher production of OH. Influence of Fe was more remarkable on the degradation of hydrophilic SDZ, and its degradation kinetics was well fitted by two-stage kinetic model. However, the Fe and HO were unproductively wasted, which could not be improved by changing the dosing modes of Fe. The presence of P25 under visible light irradiation could significantly accelerate SDZ degradation at small amount of iron precursors, mainly via promoting the Fe/Fe cycling by the photoelectrons. Moreover, SDZ degradation in sono-Fenton process was significantly inhibited at pH > 7, but the inhibition was very weak in P25-assisted sono-Fenton process. The presence of P25 also improved the mineralization. Three primary degradation pathways of SDZ degradation were proposed, including the attacking of the benzene ring, the oxidation of the amino group and the extrusion of SO.
开发先进的处理方法以最大限度地减少新兴污染物向自然水体的释放已经成为人们关注的焦点。本研究采用声芬顿工艺降解双酚 A（BPA）和磺胺嘧啶（SDZ）。原位生成的 HO 被用作唯一的来源。结果表明，由于 OH 的生成量较高，400 kHz 超声波比 20 kHz 仪器更有效地产生均相声芬顿。Fe 的影响对亲水性 SDZ 的降解更为显著，其降解动力学很好地符合两段动力学模型。然而，Fe 和 HO 被浪费掉了，改变 Fe 的投加方式并不能改善这种情况。在可见光照射下，P25 的存在可以显著地在少量铁前体的情况下加速 SDZ 的降解，主要是通过光电子促进 Fe/Fe 循环来实现。此外，在 pH>7 时，声芬顿体系中 SDZ 的降解受到显著抑制，但在 P25 辅助的声芬顿体系中抑制作用很弱。P25 的存在也提高了矿化程度。提出了 SDZ 降解的 3 条主要降解途径，包括苯环的攻击、氨基的氧化和 SO 的挤出。
