Federal Institute of Hydrology, Mainzer Tor 1, Koblenz 56068, Germany.
Department of Chemical Engineering, Lund University, PO Box 124, Lund 221 00, Sweden.
Environ Sci Technol. 2020 Sep 1;54(17):10588-10598. doi: 10.1021/acs.est.0c01454. Epub 2020 Aug 11.
Due to the increasing use and high excretion rates, high quantities of the antidiabetic drug sitagliptin (STG) enter wastewater treatment plants (WWTPs). In conventional biological treatment, only a moderate removal was achieved, and thus, STG can be detected in WWTP effluents with concentrations in the higher ng/L range. Ozonation is a widely discussed technique for advanced wastewater treatment. In lab-scale experiments, STG showed pH-dependent removal kinetics with a maximum apparent rate constant of k ∼1 × 10 M s at pH ≥ 9. With an apparent rate constant of k = (1.8 ± 0.7) × 10 M s at pH 8, STG can be considered to be readily degraded by ozonation of WWTP effluents. Ozone attacks the primary amine moiety of STG, leading to nitro-STG (TP 437) (the primary amine moiety is transformed into a nitro group). Furthermore, a diketone (TP 406) was formed, which can be further degraded by ozone. Lab-scale and pilot-scale experiments on ozonation of WWTP effluents confirmed that the ozone attack of STG was incomplete even at high ozone doses of 1.7 and 0.9 mg O/mg DOC, respectively. These experiments confirmed that nitro-STG was formed as the main TP in the wastewater matrix. Two other TPs, TP 421c and TP 206b, were also detected, albeit with low intensities.
由于抗糖尿病药物西他列汀（STG）的使用量不断增加和排泄率高，大量 STG 进入到污水处理厂（WWTP）。在传统的生物处理中，只有中等程度的去除效果，因此 STG 可以在 WWTP 废水中检测到，浓度在较高 ng/L 范围内。臭氧氧化是一种广泛讨论的废水深度处理技术。在实验室规模的实验中，STG 表现出 pH 依赖性的去除动力学，在 pH≥9 时最大表观速率常数 k∼1×10 M s。在 pH 8 时，表观速率常数 k=（1.8±0.7）×10 M s，STG 可以被认为是易于通过 WWTP 废水的臭氧氧化降解。臭氧攻击 STG 的伯胺部分，导致硝基-STG（TP 437）（伯胺部分转化为硝基）。此外，还形成了二酮（TP 406），它可以进一步被臭氧降解。臭氧氧化 WWTP 废水的实验室规模和中试规模实验证实，即使在分别为 1.7 和 0.9 mg O/mg DOC 的高臭氧剂量下，STG 的臭氧攻击也不完全。这些实验证实，硝基-STG 是作为废水基质中的主要 TP 形成的。还检测到另外两种 TP，TP 421c 和 TP 206b，但强度较低。
