【作者】 刘咏；

【导师】 刘丹；

【作者基本信息】 西南交通大学 ， 市政工程， 2007， 博士

【摘要】 针对模拟循环式准好氧垃圾填埋场渗滤液具有有机物浓度较低、可生化性差、氨氮浓度低，矿化度高（表现为氯离子浓度高）等特点，在实验室尺度范围内着重研究阳极材料对这类渗滤液电解去除效果的影响，氯离子在电解处理过程中的形态转化以及渗滤液中某些难生物降解或有毒有机物在氯离子体系中的电解氧化动力学及电解氧化途径；初步探讨了电解过程中渗滤液的可生化性与溶解性有机物分子量分布变化的关系；对比分析了以电化学技术作为全处理和预处理该类渗滤液的工艺条件和处理效果，为电化学技术在处理难降解有机废水中的应用提供理论依据和技术参数。通过小试实验比较深入地探讨了阳极材料对垃圾渗滤液电解处理效果的影响。实验结果表明，①在用β-PbO₂阳极电解处理过程中，电解质的氧化还原反应速率较快，阳极上流过的电流最大，电催化性能最好：②阳极材料不同，在相同情况下对渗滤液中各项指标的去除效果不同。电解处理氯离子含量较高的渗滤液时应选用Ru-Ir／Ti阳极，它能促进CIO^-的生成，有利于有机物的降解，对COD去除效果最好；电解处理氯离子含量很低的渗滤液时，宜选用电催化性能较好的β-PbO₂阳极；③采用不同阳极材料进行电解处理时，渗滤液中有机物分子量分布变化的趋势不同。当用PbO₂阳极电解处理时，随着电解时间的增加，各种有机物的比例变化不明显：当分别用Ru-Ir／Ti阳极和MMO阳极电解处理时，可使分子量小于2×10³u有机物的比例从67.6％分别上升到77.6％和87.2％。渗滤液中氯离子在电解处理中的作用主要从渗滤液中氯离子初始浓度的作用、氯离子在电解过程中的形态转化及在氯离子体系中典型有机物的电解氧化特性三个方面进行了探讨。研究表明：①当渗滤液中氯离子初始浓度在0～12.5g／L时，渗滤液中有机物的去除负荷（消耗单位能量所去除的有机物量）随着Cl^-初始浓度的增大而增大；当渗滤液中氯离子初始浓度大于12.5g／L及电解时间较长时，氯离子初始浓度对有机物去除负荷的作用效果不明显。在相同的条件下，当电解处理高COD渗滤液时，氯离子初始浓度对有机物去除负荷的影响程度更大；②渗滤液中的氯元素在电解处理过程中的主要存在形态为Cl^-、CIO^-和Cl₂，在实验所用的电解条件下，平均有85.8％的氯以Cl^-形式和CIO^-形式留在电解液中，平均有3.95％的氯以Cl₂形式从渗滤液中逸出，若在不利的条件下电解，会使氯气逸出的比例增加到23.1％；③当渗滤液中大分子的腐植酸和小分子的苯酚分别在氯离子体系中电解氧化时都能得到很好地去除和降解，电解过程中CIO^-产生的间接氧化作用不仅可有效地破坏腐植酸的大分子结构，使它降解为小分子量的有机物，而且还可增加苯酚的氧化速率。直接氧化对有机物的降解作用很差，当电解处理这类废水时，添加一定量的Cl^-促进CIO^-的生成很有必要。苯酚和腐植酸在氯离子体系中的电解产物除了有CO₂这样的小分子气体外，还生成了有机氯中间体和最终产物，这可能会限制电化学氧化法的应用，在电解处理含氯的有机废水时必须考虑有机氯的形成和控制问题。通过小试实验对电解过程中渗滤液的可生化性与渗滤液中溶解性有机物分子量分布变化的关系也进行了初步探讨。实验结果表明，①在电解处理时渗滤液中分子量大于100×10³u有机物的分解，可使渗滤液BOD₅／COD从0.011提高到0.152。②对分子量小于100×10³u的有机物进行生物处理时，其去除量与生物处理时的有机负荷及有机物的组成有关，与有机物分子量的大小没有直接关系。通过小试实验探讨了电化学一步法和电化学—生物复合法处理垃圾渗滤液的工艺条件。研究结果表明：①当用Ru-Ir／Ti阳极一步法电解处理垃圾渗滤液时，去除COD的最佳条件为pH 9，电解时间60min，氯离子浓度8.8g／L，电流密度9 mA／cm²。在此条件下电解处理垃圾渗滤液，可使垃圾渗滤液的COD从1360mg／L降低至89 mg／L，达到国家一级排放标准（GB16889—1997）；②电流密度越小或电解时间越长，越有助于渗滤液可生化性的提高，强碱性条件下电解不利于渗滤液可生化性的提高，β-PbO₂阳极和MMO阳极的电解预处理效果相当。用MMO阳极电解预处理垃圾渗滤液的适宜条件是电流密度3A／dm²，pH9，氯离子初始浓度8.8g／L，电解时间40min，极板间距2cm。在此条件下电解处理垃圾渗滤液，可使渗滤液BOD₅／COD的比值从0.093提高至0.32。对电解预处理后的垃圾渗滤液用SBR工艺进行生物处理。在温度25℃，有机负荷0.15kgCOD／kgSS，曝气时间5h的工艺条件下处理渗滤液，可有效地降低渗滤液的COD。渗滤液经过电解预处理-生物处理后可使COD从1360mg／L降到275mg／L，达到国家二级排放标准（GB16889—1997）。③就COD的去除效果而言，电化学—生物复合处理法比电化学一步处理法差，但电化学—生物复合处理法具有较低的运行成本。更多还原

【Abstract】 The characteristics of analogy recycling semi-aerobic landfill leachate is that the COD concentration and the ammonia-N concentration are low, the biodegradability is poor, the degree of mineralization is great, it manily express that the chlorine ion concentration is great. Base on the leachate characteristics,in the lab test range, mainly study the influence of anode material on the treatment result,study the conversation of chlorine ion during the electrolytic treatment,study the electrolytic oxidation kinetics of inhibition biodegradation or toxic organic matters in the chlorine ion regime . The relationship between the biodegradability of leachate and the the molecular weight distribution of dissolved organic matters is also discussed preliminarily. Contrast study the technological condition and the treatment result which use electrolytic technology as full-treatment and pre-treatment for this leachate.Provided a theoretic base and. technical parameters for the application of electrochemical technology to treat for inhibition biodegradation organic wastewater.The influence of anode material on the result of electrolytic treatment is discussed for leachate from lab test. It shows that （1）when useβ-PbO₂ anode to electrolytic treat for the leachate, the oxidation -reduction reaction rate of electrolyte and electro-catalytic permormance is the greatest, the current of anode is the greatest, （2）if the anode material is different ,the removal result of every index is also different .when use Ru-Ir/Ti anode to electrolytic leachate, it can accelerate the Cl^-to oxidize into ClO^- which can produce indirect oxidation to accelerate the degradation of organic, so the COD removal result is the best. When treat the leachate concluding the little Cl^-, to use theβ-PbO₂ anode is suitble.（3） the trend of the molecular weight distribution is different if the anode material is different. When useβ-PbO₂ anode, with increasing the electrolytic time, the radio of all kinds of organic matters change little; when separately use Ru-Ir/Ti anode and MMO anode ,the radio of organic matters that molecular weight are below 2×10³u can increase from 67.6% to 76.6% and 87.2% separately.The chlorine ion functions during the electrolytic treatment leachate discusses from three spheres that is the function of chlorine, the morphological conversion of chlorine ion and the electrolytic oxidation characteristics of typical organic matters. The experiment result shows that（1）when the initial chloride ion concentration in the leachate is in 0-12. 5g/L, the removal load of organic matters increase with increasing the initial chloride ion concentration in the leachate. If the initial chloride ion concentration was over 12.5g/L and the electrolytic time is longer, the influence degree of initial chloride ion concentration is little. When treats high concentration leachate, the influence degree of initial chloride ion concentration on the removal load of organic matters is greater. （2） in the electrolytic test condition, the mainly morphological of chloride ion was mainly Cl^-, residual chloride and Cl₂, the average content of Cl^- morphological and residual chloride morphological is 85.8% and the average content of Cl₂ which gave out from the leachate is3.95%.If electrolytic leachate in the bad condition, the content of Cl₂ which gave out can increase to 23.1%. （3）when electrolysis leachate in the Cl^- system, the humic acid and phenol can be removed and degraded. The indirect oxidation of ClO^- can not only make the high molecular weight organics degrade to low molecular weight organics, but also increase the removal rate of phenol. The ability of direct oxidation organic matters is bad. When electrolytic treatment this kind wastewater , it is necessary to add some Cl^- in order to improve the formation of ClO^- .The electrolytic production are the middle matters of organic chloride and final matters of organic chloride besides dicarbonate . This may limit the application of electrochemical technology .Must consider the production and control of organic chloride when electrolysis organic wastewater concluding chloride ion.The relationship between the biodegradability of leachate and the the molecular weight distribution of dissolved organic matters is also discussed by lab test. It shows that（1） the degradation of the organic matters that molecular weight are above 100×10³u can increase the BOD₅/COD of leachate from 0.011 into 0.152. （2）when use biology technology treat leachate, the removal of the organic matters which molecular weight are below 100×10³u relate to the organic load and the organic composition. It hasn’t direct relationship to its molecular weight.The technological condition of treatment leachate when use alone electrochemical technology and electrochemical-biology complex technology respectively is also studied. The result shows that （1）when use Ru-Ir/Ti anode to treat leachate ,the best technological condition of removal COD is that pH is 9,the electrolytic time is 60min, chloride ion concentration is 8.8g/L and the current density is 9 mA/cm². The COD of leachate can be deduced from 1360mg/L to 89 mg/L and be satisfied for the one grade discharge standard （GB16889—1997）,when electrolytic in this condition.（2） if the current density is smaller or the electrolytic time is longer ,it help to increase the biodegradability of leachate .Electrolytic treatment in the base condition is bad to increase the biodegradability ,the treatment result ofβ-PbO₂ anode is idential to MMO anode. When use MMO anode to electrolytic pre-treat the leachate, the suitable technological condition is that pH is 9,the electrolytic time is 40min, chloride ion concentration is 8.8g/L ,the interval of electrode is 2cm and the current density is 3mA/cm². The BOD₅/COD of leachate can increase from 0.093 to 0.32. Use SBR technological to treat the leachate after treated by electrolytic. When treat the leachate in the condition of that temperature is 25℃, the organic matter load is 0.15kgCOD/kgSS,the reaction time is 5 h, the COD of leachate can be deduced effectively .The COD can be deduced from 1360mg/L to 275mg/L and be satisfied for the two grade discharge standard （GB16889—1997） .（3） in the removal of COD, electrochemical-biology complex technology is worse than the alone electrochemical technology, but it has little running cost.更多还原