Wang Xiangyu, Liu Peng, Fu Minglai, Ma Jun, Ning Ping
Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China.
Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
Chemosphere. 2016 Jul;155:39-47. doi: 10.1016/j.chemosphere.2016.04.022. Epub 2016 Apr 19.
A novel synergistic technology based on nano zero-valent iron (NZVI) and potassium permanganate (KMnO4) was developed for treatment of dye wastewater. The synergistic technology was significantly superior, where above 99% of methylene blue (MB) was removed, comparatively, removal efficiencies of MB with the sole technology of NZVI and KMnO4 at pH 6.39 being 52.9% and 63.1%, respectively. The advantages of this technology include (1) the in situ formed materials (manganese (hydr)oxides, iron hydroxides and MnFe oxide), resulting in the stable and high removal efficiency of MB and (2) high removal capacity in a wide range of pH value. Compared with simultaneous addition system of NZVI and KMnO4, MB removal was remarkably improved by sequential addition system, especially when KMnO4 addition time was optimized at 20 min. Analyses of crystal structure (XRD), morphological difference (FE-SEM), element valence and chemical groups (XPS) of NZVI before and after reaction had confirmed the formation of in situ materials, which obviously enhanced removal of MB by oxidation and adsorption. More importantly, the roles of in situ formed materials and degradation mechanism were innovatively investigated, and the results suggested that NCH3 bond of MB molecule was attacked by oxidants (KMnO4 and in situ manganese (hydr)oxides) at position C1 and C9, resulting in cleavage of chromophore. This study provides new insights about an applicable technology for treatment of dye wastewater.
开发了一种基于纳米零价铁（NZVI）和高锰酸钾（KMnO₄）的新型协同技术用于处理染料废水。该协同技术具有显著优势，其中亚甲基蓝（MB）的去除率超过99%，相比之下，在pH 6.39时，单独使用NZVI和KMnO₄技术对MB的去除率分别为52.9%和63.1%。该技术的优点包括：（1）原位形成的材料（锰（氢）氧化物、氢氧化铁和锰铁氧化物），使MB的去除效率稳定且高；（2）在较宽的pH值范围内具有高去除能力。与NZVI和KMnO₄同时添加体系相比，顺序添加体系显著提高了MB的去除率，尤其是当KMnO₄添加时间优化为20分钟时。对反应前后NZVI的晶体结构（XRD）、形态差异（FE-SEM）、元素价态和化学基团（XPS）进行分析，证实了原位材料的形成，这明显增强了通过氧化和吸附对MB的去除。更重要的是，创新性地研究了原位形成材料的作用和降解机制，结果表明MB分子的NCH₃键在C1和C9位置受到氧化剂（KMnO₄和原位锰（氢）氧化物）的攻击，导致发色团断裂。本研究为染料废水处理的适用技术提供了新的见解。
