This work describes for the first time the photolytic and photocatalytic degradation of 6-chloronicotinic acid (6CNA) in double deionised water, which is a degradation product of neonicotinoid insecticides imidacloprid and acetamiprid, and it is known to appear in different environmental matrices. Photolytic experiments were performed with three UVA (ultraviolet A) polychromatic fluorescent lamps with broad maximum at 355 nm, while photocatalytic experiments were performed using immobilised titanium dioxide (TiO₂) on six glass slides in the spinning basket inside a photocatalytic quartz cell under similar irradiation conditions. Photolytic degradation revealed no change in concentration of 6CNA within 120 min of irradiation, while the photocatalytic degradation within 120 min, obeyed first-order kinetics. The observed disappearance rate constant was k=0.011 ± 0.001 min⁻¹ and t½ was 63.1 ± 5.5 min. Mineralisation rate was estimated through total organic carbon (TOC) and measurements revealed no carbon removal in case of photolysis after 120 min of exposure. However in photocatalytic experiments 46 ± 7% mineralisation was achieved within 120 min of irradiation. Nevertheless, the removal of total nitrogen (TN) was not observed across all experiments. Ion chromatographic analyses indicated transformation of chlorine atoms to chloride and increase of nitrate(V) ions only via photocatalytic experiments. Efficiency of selected advanced oxidation process (AOP) was investigated through toxicity assessment with Vibrio fischeri luminescent bacteria and revealed higher adverse effects of treated samples on bacteria following photocatalytic degradation in spite of the fact that higher mineralisation was achieved. New hydroxylated product generated in photocatalytic experiments with TiO₂, was confirmed with liquid chromatography-electro spray ionisation mass spectrometry (LC-ESI-MS/MS) analyses, gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (¹H NMR).

中文翻译：

---

6-氯烟酸的光催化和光催化降解。

这项工作首次描述了双去离子水中6-氯烟酸（6CNA）的光催化和光催化降解，这是新烟碱类杀虫剂吡虫啉和对乙酰氨基虫的降解产物，并且已知会在不同的环境基质中出现。用三个在355 nm处具有最大最大值的UVA（紫外线A）多色荧光灯进行光催化实验，而在相似的辐照条件下，使用固定的二氧化钛（TiO 2）在光催化石英电池内部的旋转篮中的六个载玻片上进行光催化实验。 。光解降解显示在辐射120分钟内6CNA的浓度没有变化，而在120分钟内光催化降解遵循一级动力学。观察到的消失速率常数为k ＝ 0.011±0.001min-1，t1 / 2为63.1±5.5min。矿化速率是通过总有机碳（TOC）估算得出的，测量表明在暴露120分钟后光解没有碳去除。然而，在光催化实验中，在辐射120分钟内实现了46±7％的矿化。然而，在所有实验中都未观察到总氮（TN）的去除。离子色谱分析表明，仅通过光催化实验，氯原子转化为氯离子，硝酸根（V）离子增加。通过使用费氏弧菌发光细菌进行毒性评估，研究了选定的高级氧化过程（AOP）的效率，尽管发现了更高的矿化度，但发现经过光催化降解后，处理过的样品对细菌具有更高的不利影响。用液相色谱-电喷雾电离质谱（LC-ESI-MS / MS）分析，气相色谱-质谱（GC-MS）和核磁共振波谱（¹HNMR）证实了TiO 2光催化实验中产生的新羟基化产物。 ）。