Novel sequential process for enhanced dye synergistic degradation based on nano zero-valent iron and potassium permanganate.
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.
Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China.
Xiangyu
X
Wang
Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China.
Peng
P
Liu
Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
Minglai
M
Fu
School of Municipal and Environmental Engineering, State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090, China.
Jun
J
Ma
Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China. Electronic address: ningping58_2015@sina.com.
Ping
P
Ning
D000327:Adsorption; D004396:Coloring Agents / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008751:Methylene Blue / Q000737:chemistry*; D011196:Potassium Permanganate / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
D004396:Coloring Agents; D014874:Water Pollutants, Chemical; D011196:Potassium Permanganate; D007501:Iron; D008751:Methylene Blue
In situ formed materials; Methylene blue; Nano zero-valent iron; Potassium permanganate; Synergistic technology