The evolution of the analytical techniques allowed the detection of pollutants so called contaminants of emerging concern (CEC). Water scarcity is a reality lived by some populations. Thus, water reuse is mandatory to minimize this problematic. This implies that wastewater treatments must be improved. The Advanced Oxidation Processes (AOP) such as photocatalysis and ozonation can be suitable solutions for CECs abatement. Also, TiO₂ powder catalyst is an important material in this field. However, its powder form presents a huge obstacle for industrial application, and the solution may be to support this material.

This work studies the degradation of a mixture of 3 parabens by photocatalysis, catalytic and photocatalytic ozonation using TiO₂ nanotube arrays (NTs). The studied catalysts were produced using electrolyte solutions with different ages, so the nanotubes growth ocurred at 5 (NTs_5) and 20 (NTs_20) anodization cycles. The toxicological assessment for the initial mixture, final samples and along the reaction time was performed using the cress seeds Lepidium sativum and the bacteria Aliivibrio fischeri. The photocatalysis with UVA radiation led to 50 % and 35 % parabens removal for NTs_5 and NTs_20 catalysts. This can be related to the different dimensional characteristics of the nanotubes. Ozone technologies led to total parabens degradation with an improvement when catalytic ozonation was applied. The use of NTs as catalysts in ozonation also reduced the transferred ozone dose (TOD) required for total parabens abatement when compared to single ozonation. The main parabens degradation mechanism seems to be via direct pathway by molecular ozone. Regarding the toxicity assessment, the toxicity did not change significatively, which can be explained by the intermediate’s formation.

分析技术的发展允许检测所谓的新兴关注污染物 (CEC)。缺水是一些人口生活的现实。因此，必须强制重复使用水以最大程度地减少这一问题。这意味着必须改进废水处理。光催化和臭氧化等高级氧化工艺 (AOP) 可以成为减少 CEC 的合适解决方案。此外，TiO ₂粉末催化剂是该领域的重要材料。然而，它的粉末形式给工业应用带来了巨大的障碍，解决方案可能是支持这种材料。

这项工作研究了使用 TiO ₂纳米管阵列 (NT)通过光催化、催化和光催化臭氧化作用降解 3 种对羟基苯甲酸酯的混合物。所研究的催化剂是使用不同年龄的电解质溶液生产的，因此纳米管生长发生在 5 (NTs_5) 和 20 (NTs_20) 阳极氧化循环。使用水芹种子Lepidium sativum和细菌Aliivibrio fischeri对初始混合物、最终样品和反应时间进行毒理学评估. UVA 辐射的光催化导致 NTs_5 和 NTs_20 催化剂的对羟基苯甲酸酯去除率分别为 50% 和 35%。这可能与纳米管的不同尺寸特性有关。当应用催化臭氧化时，臭氧技术导致对羟基苯甲酸酯的总降解并有所改善。与单次臭氧化相比，在臭氧化中使用 NT 作为催化剂还降低了消除对羟基苯甲酸酯总量所需的转移臭氧剂量 (TOD)。对羟基苯甲酸酯的主要降解机制似乎是通过分子臭氧的直接途径。关于毒性评估，毒性没有显着变化，这可以通过中间体的形成来解释。