节点文献

高级氧化预处理及生物法联合降解PVA的研究

PVA Degradation by a Combined Method of Advanced Oxidation Pre-Treatment and Bio-Degradation

【作者】 邱咏梅

【导师】 赵春禄;

【作者基本信息】 青岛科技大学 , 环境科学, 2009, 硕士

【摘要】 近年来,国内外广泛开展了关于聚乙烯醇(PVA)废水处理的研究,对于含PVA废水的处理方法,主要分为两大类,即物化法和生化法。高级氧化工艺具有反应时间相对较短、反应过程易于控制、对有机物的降解无选择性和比较彻底等优点,成为国际上水处理领域的热点课题。但单独使用高级氧化工艺处理成本高,难以对大量工业生产废水实现工业化处理。如何使PVA废水得到良好的降解,又能降低废水处理成本,是许多科技工作者寻求的目标。而采用生物方法降解聚乙烯醇具有运行费用低、二次污染少等优点。在实际应用中,将高级氧化技术作为难降解有机废水的预处理方法,与其他生物方法联用是目前的发展趋势。本论文研究工作正是基于这种客观条件下进行的,本实验首先通过Fenton法、臭氧法和臭氧加紫外三种高级氧化法作为PVA废水的预处理,将难降解的PVA高分子化合物转化为具有较好生物降解性的中间产物,提高可生化性。在比较三种方法的基础上,选择并重点研究了影响UV/O3法的几种因素,确定了预处理的最佳条件;而后采用自己培养、分离出的PVA降解优势菌对经过UV/O3预处理的废水进行生物处理,通过正交实验,找出了PVA降解的最佳条件为:培养基初始pH为8,UV/ O3预处理时间为1h,培养温度为25℃,选择NH4NO3为氮源。在此工艺条件下,初始浓度为1.0%的PVA废水经联合降解,COD去除率可高达98.9%,处理后的废水达到安全排放要求;通过方差分析得出:UV/ O3预处理及生物法联合降解PVA工艺中,各因素对COD去除率的影响大小顺序为:pH>预处理时间>温度>氮源种类。其中pH值和预处理时间对COD去除率有显著的影响。

【Abstract】 In recent years, polyvinyl alcohol (PVA) wastewater treatment has attracted extensive interests by domestic and abroad researchers. The current treatment methods of PVA-containing wastewater are classified into two categories, namely, physical-chemical methods and bio-degradation methods. A method called advanced oxidation processing excels with advantages such as short reaction time, easily controlling, non-selective to degrading organic materials, and thorough degradation level, as an internationally hot spot in wastewater treatment research. Whereas, the high cost of using this treatment method alone becomes obstacles to its application in bulk industrial wastewater treatment. To lower the cost while keeping high proficiency of degradation of PVA wastewater is the ultimate goal of many researchers. There are advantages of little operational cost and second-pulution for bio-degrading PVA. In practice, the development trend should be a combined method utilizing advanced oxidation as pretreatment preceding biological treatment on hard-to-degrade organic wastewater. Base on this guideline, the research works in this thesis were carried out. Three advanced oxidation processing ways, including Fenton method, ozone method, ozone plus ultra-violet light were adopted to pre-treat PVA wastewater, which is transformed into a better bio-degradable intermediate product. Comparing three ways metioned above, the processing parameters of UV/O3 pre-treatment were optimized to obtain a maximum degradation level. The separated dominant PVA degrading bacteria were applied to the intermediate products. Through the designed orthogonal experiments, the main factors effecting PVA degradation were found. That is initial pH value for the medium as 8, O3/UV pre-treatment time as 1 hour, cultivating temperature as 25°C, inorganic nitrogen source selected as NH4NO3. Under such conditions, an initial PVA concentration of 1.0% containing wastewater were processed and degraded. Its COD removal ratio could reach as high as 98.9%, qualified to be safely discharged. The variance analysis result was obtained. It illustrated that the importance sequence of various factors effecting degradation in this process was pH value > pre-treatment time > temperature > inorganic nitrogen source. Among the factors, the pH value and pre-treatment time played a significant role in processing.

节点文献中: 

本文链接的文献网络图示:

本文的引文网络