Gutiérrez-Zapata Héctor M, Rojas Karen L, Sanabria Janeth, Rengifo-Herrera Julián Andrés
Environmental Microbiology and Biotechnology Laboratory, Engineering School of Environmental and Natural Resources, Engineering Faculty, Universidad del Valle - Sede Meléndez, A.A. 25360, Calle 13 No. 100-00, Santiago de Cali, Valle, Colombia.
Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. J.J. Ronco" (CINDECA), Departamento de Química, Facultad de Ciencias Exactas, UNLP-CCT La Plata, CONICET, 47 No. 257, 1900, La Plata, Buenos Aires, Argentina.
Environ Sci Pollut Res Int. 2017 Mar;24(7):6213-6221. doi: 10.1007/s11356-016-7067-5. Epub 2016 Jun 20.
This study evaluated, at laboratory scale, if the using iron naturally present (0.3 mg L) and adding 10 mg L of hydrogen peroxide was effective to remove 24.3 mgL of 2,4-dichlorophenoxyacetic acid (2,4-D) from groundwater samples by simulated solar irradiation (global intensity = 300 W m). Under these conditions, the degradation of 2,4-D reached 75.2 % and the apparition of its main oxidation byproduct 2,4-dichlorophenol (DCP) was observed. On the other hand, pH exhibited an increasing from 7.0 to 8.3 during the experiment. Experiments using Milli-Q water at pH 7.0, iron, and HO concentrations of 0.3 and 10 mg L, respectively, were carried out in order to study the effect of ions such as carbonate species, phosphate, and fluoride in typical concentrations often found in groundwater. Ion concentrations were combined by using a factorial experimental design 2. Results showed that carbonates and fluoride did not produce a detrimental effect on the 2,4-D degradation, while phosphate inhibited the process. In this case, the pH increased also from 7.0 to 7.95 and 8.99. Effect of parameters such as pH, iron concentration, and hydrogen peroxide concentration on the 2,4-D degradation by the photo-Fenton process in groundwater was evaluated by using a factorial experimental design 2. Results showed that the pH was the main parameter affecting the process. This study shows for the first time that using the photo-Fenton process at circumneutral pH and iron naturally present seems to be a promising process to remove pesticides from groundwater.
本研究在实验室规模下评估了，利用天然存在的铁（0.3毫克/升）并添加10毫克/升过氧化氢，通过模拟太阳辐射（全球强度 = 300瓦/平方米）从地下水样品中去除24.3毫克/升的2,4 - 二氯苯氧基乙酸（2,4 - D）是否有效。在这些条件下，2,4 - D的降解率达到75.2%，并观察到其主要氧化副产物2,4 - 二氯苯酚（DCP）的出现。另一方面，在实验过程中pH值从7.0升高到了8.3。分别使用pH值为7.0的超纯水、铁以及浓度为0.3和10毫克/升的过氧化氢进行实验，以研究地下水中常见的典型浓度的碳酸根离子、磷酸根离子和氟离子等的影响。通过析因实验设计2来组合离子浓度。结果表明，碳酸根离子和氟离子对2,4 - D的降解没有产生不利影响，而磷酸根离子抑制了该过程。在这种情况下，pH值也从7.0升高到了7.95和8.99。通过析因实验设计2评估了pH值、铁浓度和过氧化氢浓度等参数对地下水中光芬顿法降解2,4 - D的影响。结果表明，pH值是影响该过程的主要参数。本研究首次表明，在近中性pH值和天然存在铁的情况下使用光芬顿法似乎是一种从地下水中去除农药的有前景的方法。
