Escuela Internacional de Doctorado (EIDO), Campus da Auga, Campus Universitário de Ourense, Universidade de Vigo, As Lagoas, 32004 Ourense, Spain.
Centro de Química de Vila Real (CQVR), Departamento de Química, Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, 5000-801 Vila Real, Portugal.
Int J Environ Res Public Health. 2023 Jan 10;20(2):1276. doi: 10.3390/ijerph20021276.
The degradation of a model agro-industrial wastewater phenolic compound (caffeic acid, CA) by a UV-A-Fenton system was investigated in this work. Experiments were carried out in order to compare batch and continuous mode. Initially, batch experiments showed that UV-A-Fenton at pH 3.0 (pH of CA solution) achieved a higher generation of HO•, leading to high CA degradation (>99.5%). The influence of different operational conditions, such as H2O2 and Fe2+ concentrations, were evaluated. The results fit a pseudo first-order (PFO) kinetic model, and a high kinetic rate of CA removal was observed, with a [CA] = 5.5 × 10−4 mol/L, [H2O2] = 2.2 × 10−3 mol/L and [Fe2+] = 1.1 × 10−4 mol/L (kCA = 0.694 min−1), with an electric energy per order (EEO) of 7.23 kWh m−3 order−1. Under the same operational conditions, experiments in continuous mode were performed under different flow rates. The results showed that CA achieved a steady state with higher space-times (θ = 0.04) in comparison to dissolved organic carbon (DOC) removal (θ = 0−0.020). The results showed that by increasing the flow rate (F) from 1 to 4 mL min−1, the CA and DOC removal rate increased significantly (kCA = 0.468 min−1; kDOC = 0.00896 min−1). It is concluded that continuous modes are advantageous systems that can be adapted to wastewater treatment plants for the treatment of real agro-industrial wastewaters.
本工作研究了 UV-A-Fenton 体系对模型农业工业废水酚类化合物（咖啡酸，CA）的降解。进行了实验以比较间歇和连续模式。最初，间歇实验表明，在 pH 3.0（CA 溶液的 pH）下的 UV-A-Fenton 产生了更高的 HO•，导致 CA 降解率很高（>99.5%）。评估了不同操作条件（例如 H2O2 和 Fe2+浓度）的影响。结果符合拟一级（PFO）动力学模型，并且观察到 CA 去除的高动力学速率，当[CA] = 5.5×10−4 mol/L、[H2O2] = 2.2×10−3 mol/L 和 [Fe2+] = 1.1×10−4 mol/L（kCA = 0.694 min−1）时，电能量/级数（EEO）为 7.23 kWh m−3 order−1。在相同的操作条件下，在不同流速下进行了连续模式实验。结果表明，与去除溶解有机碳（DOC）相比，CA 在较高的空间时间（θ = 0.04）下达到稳定状态（θ = 0−0.020）。结果表明，通过将流速（F）从 1 增加到 4 mL min−1，CA 和 DOC 的去除速率显著增加（kCA = 0.468 min−1；kDOC = 0.00896 min−1）。可以得出结论，连续模式是有利的系统，可以适应废水处理厂以处理实际的农业工业废水。
