Degradation and detoxification of 4-nitrophenol by advanced oxidation technologies and bench-scale constructed wetlands

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• 作者：J.A. Herrera-Meliá ; n ; ^{jherrera@dqui.ulpgc.es} ; A.J. Martí ; n-Rodrí ; guez ; A. Ortega-Mé ; ndez ; J. Arañ ; a ; J.M. Doñ ; a-Rodrí ; guez ; J. Pé ; rez-Peñ ; a
• 关键词：4-Nitrophenol ; Toxicity ; Constructed wetland ; TiO2-photocatalysis ; Fenton ; photoFenton
• 刊名：Journal of Environmental Management
• 出版年：2012
• 期刊代码：82_03014797
• 类别：env
• 出版时间：30 August, 2012
• 卷：105
• 期：Complete
• 页码：53-60
• 文件大小：565 K

摘要

The degradation and detoxification towards the duckweed Lemna minor of 4-nitrophenol (4NP) was聽studied by means of bench-scale constructed wetlands (CWs), TiO₂-photocatalysis and Fenton聽+聽photoFenton reactions. The main goal of this work was to compare the three treatment techniques to evaluate their possible combination for the efficient, low cost treatment of 4NP effluents. In CWs, adsorption on the substrate of 4NP was found to achieve 34-45%. Low concentrations (up to 100聽ppm) of 4NP were successfully treated by CWs in 8-12聽h. The microbial degradation of 4NP started after a lag phase which was longer with higher initial concentrations of the pollutant. The greatest degradation rate was found to occur at initial concentrations of 4NP between 60 and 90聽ppm. Solar TiO₂-photocatalysis was faster than the CWs. The greatest removals in terms of mass of 4NP removed after 6聽h of irradiation were found to occur at 4NP concentrations of about 200聽ppm. Fenton reaction provided complete 4NP degradation up to 500聽ppm in only 30聽min but TOC was removed by only about 40%. The resulting toxicities were below 20%for initial 4NP concentrations below 300聽ppm. It was the Fenton聽+聽photoFenton combination (180聽min in total) that provided TOC reductions up to 80%and negative L. minor growth inhibition for almost all the 4NP concentrations tested. The combination of solar TiO₂-photocatalysis (6聽h) with CWs (16聽h) was able to completely treat and detoxify 4NP effluents with concentrations as high as 200聽ppm of the organic.