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Fe(III)—羟基配合物体系对草甘膦的光化学转化作用

发表时间:2011-12-31  浏览量:1907  下载量:525
全部作者: 冯晓楠,王宗平,陈勇,陶涛,吴峰
作者单位: 华中科技大学环境科学与工程学院;武汉大学资源与环境科学学院
摘 要: 以草甘膦作为有机磷的代表性化合物,对其在Fe(III)—羟基配合物体系中的光化学转化规律进行研究,并对光降解途径进行初步探讨。实验以125 W的卤素灯(波长≥365 nm)为光源,在同心圆自转式反应装置上进行光化学反应;采用钼锑抗比色法检测草甘膦的光化学转化产物PO4—P;考察溶液初始pH值、草甘膦的初始浓度、金属Cu2+等因子对草甘膦光化学转化效率的影响。采用茚三酮显色实验定性地检测草甘膦的光降解产物。通过实验得出:溶液pH值为3.0~7.0时,草甘膦的光化学转化效率随溶液初始pH值升高而降低,当初始pH值为3.0,Fe(III)浓度为100 μmol·L-1,草甘膦的初始浓度为2.0 mg·L-1时,草甘膦的光化学转化效率达到最高,为34%;随着草甘膦初始浓度的增加,光化学转化效率逐渐降低;Cu2+在Fe(III)—OH体系中对草甘膦的光化学转化有明显抑制作用。
关 键 词: 水污染防治工程;草甘膦;Fe(III)—羟基配合物;光化学转化
Title: Photochemical transformation of glyphosate in the presence of Fe(III)—hydroxo complexes
Author: FENG Xiaonan, WANG Zongping, CHEN Yong, TAO Tao, WU Feng
Organization: School of Environmental Science and Engineering, Huazhong University of Science and Technology; School of Resource and Environmental Science, Wuhan University
Abstract: Glyphosate [N-(phosphonomethel)glycine] was used as a probe compound of organophosphorous to investigate its photochemical transformation behaviors in the Fe(III)—hydroxo. A proposed pathway of photolysis for glyphosate in the complexes was hypothetically presented. The photochemical transformation experiments were performed in a centric photochemical reactor of rotating type with a 125 W halogen lamp (λ≥365 nm). The concentrations of orthophosphate (PO4—P) were measured with a spectrophotometer at 700 nm. The photochemical transformation efficiencies of glyphosate were analyzed. The effects of initial pH values, the initial concentrations of glyphosate and the Cu2+ on the photochemical transformation were investigated. To test for the possibility product during the iron(III)—mediated decomposition of glyphosate, the ninhydrin tests for primary amines were run before and after irradiation. The main results and conclusion are presented as following: the photochemical transformation efficiencies of glyphosate increase with decreasing pH values in the pH range of 3.0~7.0. When the initial pH value was 3.0, the concentration of Fe(III) was 100 μmol·L-1,and the initial concentrations of glyphosate was 2.0 mg·L-1, 34% of glyphosate could be chemically transformed into orthophosphate (PO4—P). The efficiencies decreased with increasing of the initial concentrations of glyphosate in the iron(III) complexes at specific initial pH value. The cupric ions in the solution showed inhibition effect on the photochemical transformation.
Key words: water pollution control engineering; glyphosate; Fe(III)—hydroxo; photochemical transformation
发表期数: 2011年12月第24期
引用格式: 冯晓楠,王宗平,陈勇,等. Fe(III)—羟基配合物体系对草甘膦的光化学转化作用[J]. 中国科技论文在线精品论文,2011,4(24):2265-2271.
 
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