School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China.
Chemosphere. 2023 Sep;336:139246. doi: 10.1016/j.chemosphere.2023.139246. Epub 2023 Jun 15.
Tetracycline (TC) and Oxytetracycline (OTC) are common antibiotics increasingly detected in the environment, posing a potential risk to human and aquatic lives. Although conventional methods such as adsorption and photocatalysis are used for the degradation of TC and OTC, they are inefficient in removal efficiency, energy yield, and toxic byproduct generation. Herein, a falling-film dielectric barrier discharge (DBD) reactor coupled with environmentally friendly oxidants (hydrogen peroxide (HPO), sodium percarbonate (SPC), and HPO + SPC) was applied, and the treatment efficiency of TC and OTC was investigated. Experimental results showed that moderate addition of the HPO and SPC exhibited a synergistic effect (SF > 2), significantly improving the antibiotic removal ratio, total organic removal ratio (TOC), and energy yield by more than 50%, 52%, and 180%, respectively. After 10 min of DBD treatment, the introduction of 0.2 mM SPC led to a 100% antibiotic removal ratio and a TOC removal of 53.4% and 61.2% for 200 mg/L TC and 200 mg/L OTC, respectively. Also, 1 mM HPO dosage led to 100% antibiotic removal ratios after 10 min of DBD treatment and a TOC removal of 62.4% and 71.9% for 200 mg/L TC and 200 mg/L OTC, respectively. However, the DBD + HPO + SPC treatment method had a detrimental effect on the performance of the DBD reactor. After 10 min of DBD plasma discharge, the removal ratios for TC and OTC were 80.8% and 84.1%, respectively, when 0.5 mM HPO + 0.5 mM SPC was added. Moreover, principal component and hierarchical cluster analysis confirmed the differences between the treatment methods. Furthermore, the concentration of oxidant-induced in-situ generated ozone and hydrogen peroxide were quantitatively determined, and their indispensable roles during the degradation process were established via radical scavenger tests. Finally, the synergetic antibiotic degradation mechanisms and pathways were proposed, and the toxicities of the intermediate byproducts were evaluated.
四环素（TC）和土霉素（OTC）是环境中常见的抗生素，对人类和水生生物构成潜在风险。尽管吸附和光催化等传统方法可用于 TC 和 OTC 的降解，但它们在去除效率、能量产率和有毒副产物生成方面效率低下。在此，应用了下落液膜介电阻挡放电（DBD）反应器与环保氧化剂（过氧化氢（HPO）、过碳酸钠（SPC）和 HPO+SPC），并研究了 TC 和 OTC 的处理效率。实验结果表明，适量添加 HPO 和 SPC 表现出协同作用（SF>2），分别将抗生素去除率、总有机去除率（TOC）和能量产率提高了 50%、52%和 180%以上。在 10 分钟的 DBD 处理后，引入 0.2 mM 的 SPC 可使 200 mg/L TC 和 200 mg/L OTC 的抗生素去除率达到 100%，TOC 去除率分别为 53.4%和 61.2%。此外，1 mM HPO 用量可使 10 分钟的 DBD 处理后抗生素去除率达到 100%，TOC 去除率分别为 62.4%和 71.9%。然而，DBD+HPO+SPC 处理方法对 DBD 反应器的性能有不利影响。在 10 分钟的 DBD 等离子体放电后，当添加 0.5 mM HPO+0.5 mM SPC 时，TC 和 OTC 的去除率分别为 80.8%和 84.1%。此外，主成分和层次聚类分析证实了处理方法之间的差异。此外，还定量测定了氧化剂诱导的原位生成臭氧和过氧化氢的浓度，并通过自由基清除剂试验确定了它们在降解过程中的不可或缺作用。最后，提出了协同抗生素降解机制和途径，并评估了中间副产物的毒性。
