Center for Water Resource Cycle Research, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul, 02792, Republic of Korea; KU-KIST Green School, Graduate School of Energy and Environment, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
KU-KIST Green School, Graduate School of Energy and Environment, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea; School of Civil, Environmental and Architectural Engineering, Korea University, Anam-ro 145, Seongbuk-gu, Seoul, 02841, Republic of Korea.
Water Res. 2020 Apr 1;172:115514. doi: 10.1016/j.watres.2020.115514. Epub 2020 Jan 20.
Advanced oxidation processes have gained significant attention for treating tetracycline (TC) and oxytetracycline (OTC), however, their oxidation using the photo-Fenton process has not been sufficiently studied. Although degradations of TC and OTC were enhanced by increasing HO and Fe within the ranges investigated (HO = 20-50 mg/L and Fe = 1-10 mg/L) under UV irradiation, further experiments for the photo-Fenton process were conducted with 20 mg/L of HO and 5 mg/L of Fe to balance efficiency and cost. The photo-Fenton process (UV/HO/Fe) was shown to be more effective to remove TC and OTC than HO, ultraviolet (UV), and UV/HO at the same doses of oxidants. Inorganic anions and cations were shown to inhibit the degradation of TC and OTC during the photo-Fenton process, in the following order: HPO > HCO ≫ SO > Cl and Cu ≫ Ca > Na. The TC and OTC degradation are generally improved by increasing pH, which is opposite to the k values, caused by increasing the deprotonation degree of TC and OTC. Four and nine transformation products of TC and OTC, respectively, were detected over the treatment period. Among the transformation products, m/z 443.14 (CHNO) formed during TC degradation, and m/z 433.16 (CHNO) and m/z 415.15 (CHNO) formed during OTC degradation, were reported for the first time. Vibrio fischeri toxicity assessment indicated that the inhibition ratio was decreased with a decreasing TC concentration, while, OTC transformation lead to higher toxicity. The product (m/z 477.15b) was determined to be the compound causing toxicity during degradation of OTC by using the quantitative structure activity relationship (QSAR). This toxic transformation product caused higher inhibition ratios than its parental compound (OTC), but its further oxidization resulted in decreasing the inhibition ratios.
高级氧化工艺在处理四环素（TC）和土霉素（OTC）方面受到了广泛关注，然而，利用光芬顿工艺对其进行氧化的研究还不够充分。虽然在 UV 照射下，在所研究的范围内（HO = 20-50mg/L 和 Fe = 1-10mg/L）增加 HO 和 Fe 可以增强 TC 和 OTC 的降解，但为了平衡效率和成本，仍进一步进行了光芬顿工艺的实验，HO 用量为 20mg/L，Fe 用量为 5mg/L。结果表明，与 HO、紫外线（UV）和 UV/HO 相比，光芬顿工艺（UV/HO/Fe）更有效地去除 TC 和 OTC。在光芬顿过程中，无机阴离子和阳离子被证明会抑制 TC 和 OTC 的降解，抑制顺序为：HPO ＞HCO ≫ SO ＞Cl 和 Cu ＞Ca ＞Na。TC 和 OTC 的降解通常随着 pH 值的增加而提高，这与 k 值相反，因为这会增加 TC 和 OTC 的去质子化程度。在处理过程中，分别检测到 4 种和 9 种 TC 和 OTC 的转化产物。在转化产物中，在 TC 降解过程中形成的 m/z 443.14（CHNO），以及在 OTC 降解过程中形成的 m/z 433.16（CHNO）和 m/z 415.15（CHNO），均为首次报道。发光弧菌毒性评估表明，随着 TC 浓度的降低，抑制率降低，而 OTC 的转化导致更高的毒性。通过使用定量构效关系（QSAR），确定产物（m/z 477.15b）是在 OTC 降解过程中引起毒性的化合物。这种有毒转化产物引起的抑制率高于其母体化合物（OTC），但进一步氧化会降低抑制率。
