Catalytic activities of ultra-small 尾-FeOOH nanorods in ozonation of 4-chlorophenol

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• 作者：Ogheneochuko Oputu¹ ; Mahabubur Chowdhury² ; ^{chowdhurym@cput.ac.za" class="auth_mail" title="E-mail the corresponding author} ; Kudzanai Nyamayaro¹ ; Olalekan Fatoki¹ ; Veruscha Fester²
• 关键词：Ultra-small 尾-FeOOH ; Heterogeneous&ndash ; homogeneous catalysis ; Catalytic ozonation ; Waste water treatment
• 刊名：Journal of Environmental Sciences
• 出版年：2015
• 出版时间：1 September 2015
• 年：2015
• 卷：35
• 期：Complete
• 页码：83-90
• 全文大小：609 K

文摘

We report the catalytic properties of ultra-small 尾-FeOOH nanorods in ozonation of 4-chlorophenol (4-CP). XRD, TEM, EDS, SAED, FTIR and BET were used to characterize the prepared material. Interaction between O₃ and 尾-FeOOH was evident from the FTIR spectra. The removal efficiency of 4-CP was significantly enhanced in the presence of 尾-FeOOH compared to ozone alone. Removal efficiency of 99% and 67% was achieved after 40 min in the presence of combined ozone and catalyst and ozone only, respectively. Increasing catalyst load increased COD removal efficiency. Maximum COD removal of 97% was achieved using a catalyst load of 0.1 g/100 mL of 4-CP solution. Initial 4-CP concentration was not found to be rate limiting below 2 × 10^− 3 mol/L. The catalytic properties of the material during ozonation process were found to be pronounced at lower initial pH of 3.5. Two stage first order kinetics was applied to describe the kinetic behavior of the nanorods at low pH. The first stage of catalytic ozonation was attributed to the heterogeneous surface breakdown of O₃ by 尾-FeOOH, while the second stage was attributed to homogeneous catalysis initiated by reductive dissolution of 尾-FeOOH at low pH.