Peng Guotao, Fan Zhengqiu, Wang Xiangrong, Sui Xin, Chen Chen
Department of Environmental Science and Engineering, Fudan University, Room 314, No. 220 Handan Road, Yangpu District, Shanghai 200433, China E-mail:
Water Sci Technol. 2015;72(10):1824-31. doi: 10.2166/wst.2015.404.
Microcystins (MCs) are a group of monocyclic heptapeptide toxins produced by species of cyanobacteria. Since MCs exhibit acute and chronic effects on humans and wildlife by damaging the liver, they are of increasing concern worldwide. In this study, we investigated the ability of the phthalocyanine compound (ZnPc-TiO2-SiO2) to degrade microcystin-LR (MC-LR) in the presence of visible light. X-ray diffraction (XRD) and UV-Visible diffuse reflectance spectra (UV-Vis DRS) were utilized to characterize the crystalline phase and the absorption behavior of this catalyst. According to the results, XRD spectra of ZnPc-TiO2-SiO2 powders taken in the 2θ configuration exhibited the peaks characteristic of the anatase phase. UV-Vis DRS showed that the absorption band wavelength shifted to the visible range when ZnPc was supported on the surface of TiO2-SiO2. Subsequently, several parameters including catalyst dose, MC-LR concentrations and pH were investigated. The MC-LR was quantified in each sample through high-performance liquid chromatography (HPLC). The maximum MC-LR degradation rate of 80.2% can be obtained within 300 minutes under the following conditions: catalyst dose of 7.50 g/L, initial MC-LR concentration of 17.35 mg/L, pH 6.76 and the first cycling run of the photocatalytic reaction. Moreover, the degradation process fitted well with the pseudo-first-order kinetic model.
微囊藻毒素（MCs）是由蓝藻物种产生的一组单环七肽毒素。由于微囊藻毒素通过损害肝脏对人类和野生动物表现出急性和慢性影响，因此在全球范围内受到越来越多的关注。在本研究中，我们研究了酞菁化合物（ZnPc-TiO₂-SiO₂）在可见光存在下降解微囊藻毒素-LR（MC-LR）的能力。利用X射线衍射（XRD）和紫外-可见漫反射光谱（UV-Vis DRS）来表征该催化剂的晶相和吸收行为。结果表明，在2θ构型下采集的ZnPc-TiO₂-SiO₂粉末的XRD光谱显示出锐钛矿相的特征峰。UV-Vis DRS表明，当ZnPc负载在TiO₂-SiO₂表面时，吸收带波长移至可见光范围。随后，研究了包括催化剂剂量、MC-LR浓度和pH值在内的几个参数。通过高效液相色谱（HPLC）对每个样品中的MC-LR进行定量。在以下条件下，300分钟内MC-LR的最大降解率可达80.2%：催化剂剂量为7.50 g/L，初始MC-LR浓度为17.35 mg/L，pH值为6.76，以及光催化反应的第一次循环运行。此外，降解过程与伪一级动力学模型拟合良好。
