Catalytic Nitrate Removal in Continuous Bimetallic Cu鈥揚d/Nanoscale Zerovalent Iron System

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• 作者：Shanawar Hamid ; Sungjun Bae ; Woojin Lee ; Muhammad Tahir Amin ; Abdulrahman Ali Alazba
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2015
• 出版时间：June 24, 2015
• 年：2015
• 卷：54
• 期：24
• 页码：6247-6257
• 全文大小：606K
• ISSN：1520-5045

文摘

In this study, we investigated catalytic nitrate removal using nanoscale zerovalent iron (NZVI) supported Cu鈥揚d bimetallic catalyst (Cu鈥揚d/NZVI) in a continuous reactor system. Control experiments showed that Cu, Pd, and a proper supply of H₂ are essential for relatively sustainable nitrate (30 mg/L NO₃^{鈥?/sup>-N) reduction in continuous mode. When we optimized operational parameters to enhance removal efficiency and N₂ selectivity, we finally achieved complete nitrate removal with 48% N₂ selectivity at 9 h. During a longevity test (200 h reaction), excellent removal was observed (>91% in 24 h) with 42鈥?0% N₂ selectivity. However, removal gradually decreased to 13% in 200 h with increasing nitrite production. X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy analysis revealed that both the support (NZVI) and the Cu(0) oxidized after continuous denitrification. This indicated that loss of NZVI reductive capacity and the oxidation of Cu(0) to Cu(I) and Cu(II) deactivated nitrate removal during the continuous nitrate reduction by Cu鈥揚d/NZVI.}