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在平推流光化学反应器中采用纳米TiO2光催化矿化N-(膦酰基甲基)甘氨酸(草甘膦)溶液,考察了多种因素对矿化效果的影响。结果表明,在碱性溶液中,OH-可以充当光致空穴的俘获剂,从而提高了草甘膦的光催化矿化效率;外加氧化剂可以作为电子的接受体,通过接受光生电子来抑制光生电子与光生空穴的复合,提高光催化反应的量子产率,从而促进草甘膦的光催化矿化;升高温度可促进具有强氧化性自由基的生成,同时也可抑制光生电子和光生空穴的复合,促进草甘膦在催化剂表面的矿化;外加有机物可与草甘膦共同竞争催化剂表面的活性位点,从而阻碍了草甘膦在催化剂表面的矿化;在一定范围内,光催化矿化率随无机离子浓度的增加而升高,但当无机离子的质量浓度>4 mg/L时,矿化率下降。
Nano-TiO2 photocatalytic mineralization of N- (phosphonomethyl) glycine (glyphosate) solution was applied to the flat flow photochemical reactor. The effects of various factors on the mineralization were investigated. The results show that OH- can act as a photo-hole-trapping agent in alkaline solution to improve the photocatalytic mineralization efficiency of glyphosate. The addition of oxidant can act as acceptor of electrons and can inhibit photogeneration by photogenerated electrons Electron and photo-generated holes to increase the quantum yield of photocatalytic reaction, thereby promoting the photocatalytic mineralization of glyphosate; increasing the temperature can promote the formation of strong oxidizing radicals, but also can inhibit the photogenerated electron and photogenerated Hole recombination to promote glyphosate mineralization on the surface of the catalyst; addition of organic compounds and glyphosate can compete with the active site on the catalyst surface, which hindered the glyphosate in the catalyst surface mineralization; within a certain range, The photocatalytic mineralization rate increased with the increase of inorganic ion concentration, but the mineralization rate decreased when the mass concentration of inorganic ions was> 4 mg / L.