Key Laboratory of the Coastal and Wetland Ecosystems (Xiamen University), Ministry of Education, College of the Environment and Ecology, Xiamen University, Xiamen 361102, Fujian, China.
Key Laboratory of the Coastal and Wetland Ecosystems (Xiamen University), Ministry of Education, College of the Environment and Ecology, Xiamen University, Xiamen 361102, Fujian, China.
Environ Pollut. 2019 Dec;255(Pt 1):113182. doi: 10.1016/j.envpol.2019.113182. Epub 2019 Sep 7.
Methylene blue (MB) is a dye pollutant commonly present in textile wastewater. We investigate and critically evaluate the applicability of BaTiO/GO composite for photodegradation of MB in synthetic wastewater under UV-vis irradiation. To enhance its performance, the BaTiO/GO composite is varied based on the BaTiO weight. To compare and evaluate any changes in their morphologies and crystalline structures before and after treatment, BET (Brunauer-Emmett-Teller), XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), SEM (scanning electron microscopy) and TEM (transmission electron microscopy) tests are conducted, while the effects of reaction time, pH, dose of photocatalyst and initial MB concentration on its photodegradation by the composite are also investigated under identical conditions. The degradation pathways and removal mechanisms of MB by the BaTiO/GO are elaborated. It is evident from this study that the BaTiO/GO composite is promising for MB photodegradation through ·OH. Under optimized conditions (0.5 g/L of dose, pH 9.0, and 5 mg/L of MB concentration), the composite with 1:2 dose ratio of BaTiO/GO has the highest MB degradation rate (95%) after 3 h of UV vis irradiation. However, its treated effluents still could not comply with the discharge standard limit of less than 0.2 mg/L imposed by national environmental legislation. This suggests that additional biological treatments are still required to deal with the remaining oxidation by-products of MB, still present in the wastewater samples such as 3,7-bis (dimethyl-amino)-10H-phenothiazine 5-oxide.
亚甲蓝（MB）是一种常见的纺织废水中的染料污染物。我们研究并批判性地评估了 BaTiO/GO 复合材料在紫外可见辐射下对合成废水中 MB 的光降解的适用性。为了提高其性能，根据 BaTiO 的重量改变 BaTiO/GO 复合材料。为了比较和评估处理前后其形态和晶体结构的任何变化，进行了 BET（Brunauer-Emmett-Teller）、XRD（X 射线衍射）、FTIR（傅里叶变换红外光谱）、SEM（扫描电子显微镜）和 TEM（透射电子显微镜）测试，同时还在相同条件下研究了反应时间、pH 值、光催化剂剂量和初始 MB 浓度对其光降解的影响。阐述了 MB 被 BaTiO/GO 降解的途径和去除机制。从这项研究中可以明显看出，BaTiO/GO 复合材料有望通过·OH 实现 MB 的光降解。在优化条件（剂量 0.5g/L、pH9.0 和 MB 浓度 5mg/L）下，BaTiO/GO 剂量比为 1:2 的复合材料在 3h 的紫外可见辐射后具有最高的 MB 降解率（95%）。然而，其处理后的废水仍不能符合国家环境法规规定的低于 0.2mg/L 的排放限值。这表明仍然需要额外的生物处理来处理废水样品中仍然存在的 MB 的剩余氧化副产物，例如 3,7-双（二甲氨基）-10H-吩噻嗪 5-氧化物。
