2，4-D废水的臭氧、臭氧/双氧水处理技术研究

【作者】 董里；

【导师】 史惠祥；

【作者基本信息】 浙江大学 ， 环境工程， 2004， 硕士

【摘要】 本文研究了2,4-D废水在O₃和O₃/H₂O₂氧化中的影响因素、去除动力学和降解机理，为臭氧氧化技术处理2,4-D废水的设计、优化和控制提供必要的依据。 对2,4-D废水进行了O₃氧化降解实验研究。在O₃氧化2,4-D的反应中，pH值升高有利于反应；反应温度升高反应速率加快；提高气体流量有利于2,4-D的O₃氧化反应；2,4-D初始浓度增加，2,4-D去除率降低，但绝对降解量增大。通过对实验数据的分析，认为2,4-D的去除过程符合拟一级反应动力学。通过GC-MS、HPLC和IC分析，检测出反应中间产物2,4-二氯苯氧甲醛、2,4-二氯苯酚、草酸、顺丁烯二酸等，并推出O₃氧化降解2,4-D的反应路径。 在单独O₃氧化的基础上，对2,4-D废水进行了O₃/H₂O₂氧化降解研究。在O₃/H₂O₂氧化2,4-D的反应中，pH值升高有利于反应；反应温度升高时，反应速率加快，但是温度越高反应速率的提高的程度也越小；提高气体流量有利于反应；2,4-D初始浓度越大去除率越低，但绝对降解量越大；H₂O₂投加量越大2,4-D的去除速率越快；H₂O₂的投加方式对2,4-D的去除率影响不大。通过对实验数据的分析，认为2,4-D在O₃/H₂O₂体系中的去除过程符合拟一级反应动力学。通过GC-MS、HPLC、IC分析，检测出中间产物2,4-二氯苯酚、乙醇酸、乙醛酸、苯醌、顺丁烯二酸、草酸等，并推出O₃/H₂O₂氧化降解2,4-D的反应途径。 实验发现，O₃/H₂O₂氧化比O₃单独氧化更能有效地降低COD和TOC，COD和TOC去除率分别是O₃单独氧化的191％和325％，弥补了O₃单独氧化的缺陷。而且O₃/H₂O₂氧化比O₃单独氧化不仅更有效而且经济性更加明显。更多还原

【Abstract】 An investigation of kinetics and reaction mechanisms of 2,4-Dichlorophenoxyacetic acid (2,4-D) degraded by O3 and O3/H2O2 system was performed, and gists for treating with wastewater containing 2,4-D were afforded.During ozonation of 2,4-D, the remove rate of 2,4-D increased with increasing pH of solution, increasing temperature and enhancing gas flow rate, but the degree of enhancing descended with high temperature. The remove rate of 2,4-D decreased with increasing concentration of 2,4-D. The intermediates were identified by GC-MS, HPLC and IC. The 2,4-D decay followed a pseudo first-order reaction. A possible reaction pathway for 2,4-D degradation by O3 involving all intermediates detected was proposed.During catalytic ozonation of 2,4-D with H2O2, the remove rate of 2,4-D decreased with increasing pH of solution, increasing temperature, enhancing gas flow rate and increasing dosage of H2O2, but the degree of enhancing descended with high temperature. The remove rate of 2,4-D decreased with increasing concentration of 2,4-D. The methods of adding H2O2 had scarcely any influence on the remove rate of 2,4-D. The intermediates were identified by GC-MS, HPLC and IC. A possible reaction pathway for 2,4-D degradation by H2O2 involving all intermediates detected was proposed.Comparing with ozonation of 2,4-D, catalytic ozonation of 2,4-D with H2O2 showed higher TOC and COD remove rate owing to the hydroxyl radical produced by catalytic ozonation with H2O2, and was more economical.更多还原