Guangdong Polytechnic of Environmental Protection Engineering, Foshan, 528216, Guangdong, People's Republic of China; Guangdong Engineering and Technology Research Center of Solid Waste Resource Recovery and Heavy Metal Pollution Control, Foshan, 528216, PR China; Key Laboratory of Heavy Metals Pollution Prevention and Vocational Education of Guangdong Environmental Protection of Mining and Metallurgy Industry, Foshan, 528216, PR China.
School of Environment and Energy, South China University of Technology, Guangzhou, 510006, People's Republic of China.
Environ Res. 2020 Oct;189:109876. doi: 10.1016/j.envres.2020.109876. Epub 2020 Jul 9.
As the industries advances at a fast pace, efficient and simultaneous removal of both heavy metals and organics from aqueous is essential to protecting public human health and environment. In this work, we used pyrite as reductant and catalyst for simultaneously reducing Cr(VI) and activating persulfate (PS) to degrade acid orange 7 (AO7). The results indicated that the simultaneous removal rate of AO7 and Cr(VI) by pyrite-PS was up to 100% within 60 min under acidic conditions. However, There was a competitive relationship between PS activation and Cr(VI) reduction for robbing Fe. At beginning of the reaction, the limited Fe firstly activated persulfate rather than reduce Cr(VI). The effect of dosage of pyrite and PS on Cr(VI) reduction was more significant than that on AO7 degradation. Increased pyrite dosages from 1g·L to 6 g L resulted in enhanced Cr(VI) removal, and excessive PS (more than 0.4 g L) was not beneficial to Cr(VI) removal. Electron paramagnetic resonance (EPR) spectroscopy and radical scavenger studies demonstrated that sulfate (SO·), singlet oxygen (O) and superoxide radical (·O) were the crucial reactive oxygen species (ROS) in the pyrite-PS system rather than hydroxyl radical (·OH). This study showed that the pyrite-PS system could simultaneously remove AO7 and Cr(VI), which provided a new idea for the actual wastewater treatment.
随着工业的快速发展，从水溶液中高效、同时去除重金属和有机物对于保护公众健康和环境至关重要。在这项工作中，我们使用黄铁矿作为还原剂和催化剂，同时还原六价铬（Cr(VI)）并激活过硫酸盐（PS）来降解酸性橙 7（AO7）。结果表明，在酸性条件下，黄铁矿-过硫酸盐体系在 60 分钟内可以达到 100%的同时去除 AO7 和 Cr(VI)的效果。然而，PS 活化和 Cr(VI)还原之间存在竞争关系，因为它们都需要抢夺 Fe。在反应开始时，有限的 Fe 首先激活过硫酸盐而不是还原 Cr(VI)。黄铁矿和 PS 用量对 Cr(VI)还原的影响比对 AO7 降解的影响更为显著。黄铁矿用量从 1g·L 增加到 6 g·L 会增强 Cr(VI)的去除效果，而过量的 PS（超过 0.4 g·L）不利于 Cr(VI)的去除。电子顺磁共振（EPR）光谱和自由基清除剂研究表明，在黄铁矿-过硫酸盐体系中，硫酸盐（SO·）、单线态氧（O）和超氧自由基（·O）是关键的活性氧物种（ROS），而不是羟基自由基（·OH）。本研究表明，黄铁矿-过硫酸盐体系可以同时去除 AO7 和 Cr(VI)，为实际废水处理提供了新的思路。
