【作者】 汤优敏；

【导师】 官宝红；

【作者基本信息】 浙江大学 ， 环境工程， 2006， 硕士

【摘要】 本文通过对化工制药废水处理技术和Fenton技术的综述，提出以Fenton—A／O工艺处理甲基多巴废水。分别研究了Fenton处理、Fenton处理—PAM絮凝及Fenton处理—PAM絮凝—A／O工艺处理配制的甲基多巴废水和实际生产废水。在研究了甲基多巴废水的处理效果及工艺优化之后，深入讨论了甲基多巴去除机制及其动力学，并在实验基础上实施了废水处理工程。 在利用Fenton处理目标污染物甲基多巴的时候，考察了不同工艺条件对COD_Cr去除率的影响，选择反应温度、Fe²⁺:H₂O₂摩尔比和H₂O₂浓度等三个因素，采用星点设计法，建立Fenton去除COD_Cr的数学模型。根据数学模型，在实验设计范围内的工艺条件优化预测结果与实际结果的误差小于2％，预测效果比较理想。 Fenton去除废水中的甲基多巴的机制因Fe²⁺+:H₂O₂摩尔比的不同而有显著差异。在高Fe²⁺:H₂O₂摩尔比（≥2）时，反应机制是H₂O₂促进Fe²⁺的絮凝作用；在中Fe²⁺:H₂O₂摩尔比（=1）时，反应机制是兼有氧化和絮凝沉淀作用；在低Fe²⁺:H₂O₂摩尔比（≤0.2）时，反应机制是氧化作用，包括Fe²⁺催化H₂O₂氧化和(Fe⁴⁺)_aq 高价水合铁直接络合降解。通过对反应机制的探讨，针对Fenton反应特性，建立了相应的动力学模型，模型值与实验值吻合良好，误差小于10％，反应动力学方程可以表示为： 通过对甲基多巴废水的厌氧生化、好氧生化和Fenton—A／O实验比较可以发现，经Fenton处理后废水的B/C由0.31升至0.42，可生化性得到了明显的提高。当进水甲基多巴浓度为1000mg/L，COD_Cr约为1250 mg/L时，经过Fenton—A／O工艺处理，出水的COD_Cr，低于100mg/L。 然后以甲基多巴生产废水为处理对象，进行Fenton处理—PAM絮凝—A／O生化实验，优化工艺参数。根据实验研究，确定了甲基多巴生产废水处理的工艺流程，即：Fenton处理—PAM絮凝—A／O法。工程运行表明，该工艺能够有效处理甲基多巴生产废水。更多还原

【Abstract】 According to the review of the various treatment methods of pharmaceutical wastewater and Fenton reagent, Fenton-A/O （anoxic and aerobic biodegradation） system appeared to be applicable for the treatment of Methyldopa wastewater. The processes of Fenton treatment, Fenton treatment-PAM flocculation or Fenton treatment-PAM flocculation-A/O for the composite wastewater and the industrial wastewater in which the Methyldopa was the main pollutant, were investigated respectively. The processes applicability for pollutant removal were conducted and the primary parameters were optimized in the experiment. Further more, the mechanism of Fenton to remove the methyldopa or COD_Cr was discussed and the kinetics model was proposed to describe the phenomena presented in the experiment. Finally, the processes of Fenton treatment, PAM flocculation and A/O methods were applied totreat the wastewater, and a plant was designed.Parameters, such as temperature, H₂O₂ concentration and Fe²⁺:H₂O₂ ratio, were investigated in terms of COD_Cr removal efficiency in the Fenton treatment of Methyldopa wastewater, in which a central composite design was carried out. With the COD_Cr predicated equation, the optimum conditions predicted by the model fitted very reasonably with the experimental data for the relative error below 2%.The mechanism of Methyldopa degradation by Fenton reagent was significantly different according to the Fe²⁺/H₂O₂ ratio. With high ratio of Fe²⁺:H₂O₂ （≥2） , the Fenton reaction was coagulation enhanced by H₂O₂; with medium ratio of Fe²⁺:H₂O₂ （=1 ） , the Fenton reaction could be characterized into two specific systems, oxidation and coagulation; with low ratio of Fe²⁺:H₂O₂ （≤0.2） , the Fenton reaction was oxidation, including H₂O₂ oxidation catalyzed by Fe²⁺ and degradation by a hydrated ferryl-complex Fe_aq⁴⁺. A kinetics model was adopted to describe the reaction and the rate equation could provide the evidence for the main reaction pathway, which was fitted very well with the experiment data for the relative error below 10%. The equation of reaction kinetics as follows:更多还原