Instituto de Química - Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, Porto Alegre, RS 9500, Brazil.
Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, OH 45221-0012, USA.
Water Res. 2021 Mar 1;191:116815. doi: 10.1016/j.watres.2021.116815. Epub 2021 Jan 6.
This work proposes a tube-in-tube membrane photoreactor, operated in a continuous-mode, to boost the efficiency of peroxydisulfate (PDS), through the photolytic (UV-C radiation) and photocatalytic (TiO-P25) processes. This new technology can efficiently facilitate the transportation of PDS to the catalyst surface and water to be treated. The ultrafiltration tubular ceramic membrane was used as support for the TiO-P25 and oxidant-catalyst/water contactor. Tests were performed using a synthetic solution and a municipal secondary effluent, both spiked with a pharmaceutical mix solution (paracetamol (PCT), furosemide (FRS), nimesulide (NMD), and diazepam (DZP); 200 μg L of each). At steady-state regime, the UVC/SO/TiO system, with radial PDS addition, showed the highest removal of pharmaceuticals in both matrices. Furthermore, twenty-two transformation products (TPs) were identified by applying LC-QTOF MS technique. Hence, the transformation pathways including hydroxylation in aromatic moiety by an electrophilic attack, electron transfer reactions, cleavage of C-O, C-N bond, H-abstraction and ring opening were proposed. TPs chemical structures were evaluated by in silico (Q)SAR approach using TOXTREE and EPI Suite™ software.
本工作提出了一种管中管膜光反应器，采用连续模式操作，通过光解（UV-C 辐射）和光催化（TiO-P25）过程来提高过二硫酸盐（PDS）的效率。这项新技术可以有效地促进 PDS 向催化剂表面和待处理水的传输。超滤管式陶瓷膜用作 TiO-P25 和氧化剂-催化剂/水接触器的支撑体。使用合成溶液和市政二级出水进行了测试，这两种溶液均用药物混合溶液（扑热息痛（PCT）、呋塞米（FRS）、尼美舒利（NMD）和地西泮（DZP）进行了加标，每种药物浓度为 200μg/L）。在稳定状态下，径向添加 PDS 的 UVC/SO/TiO 体系在两种基质中对药物的去除率最高。此外，通过应用 LC-QTOF MS 技术鉴定了二十二个转化产物（TPs）。因此，提出了包括芳香族部分亲电攻击的羟基化、电子转移反应、C-O、C-N 键的断裂、H 提取和开环在内的转化途径。通过使用 TOXTREE 和 EPI SuiteTM 软件的（Q）SAR 方法对 TPs 的化学结构进行了评估。
