【作者】 李溯；

【导师】 陈坚；

【作者基本信息】 江南大学 ， 环境工程， 2008， 硕士

【摘要】 市政污泥的组成极为复杂,其中含有可为微生物利用、转化的有机营养物质,也有不能转化利用甚至对微生物有毒害的有机或无机物质,导致发酵产酸混合液成分的难以预测。从市政污泥发酵产酸混合液中分离提取有机酸可消除市政污泥发酵产酸的产物抑制,提高污泥转化的效率和速度。因此,研究发酵产酸混合液中目的有机酸的分离提取技术不仅是成功实现市政污泥资源化的关键,而且对提高该工艺的整体效率和加快其产业化进程是现实而有意义的。支撑液膜分离技术是将常规的溶剂萃取和膜分离技术相结合的新型分离提取工艺,具有分离效率高,能耗低,可实现产物的连续、同步的分离和浓缩等优点。本论文首先以有机酸的提取率等为评价依据,对膜组件、萃取剂、有机溶剂和反萃取剂进行选择,在此基础上对支撑液膜法分离提取模拟有机酸混合液的工艺条件进行了优化,最后,研究了其对实际体系中有机酸的提取效果。主要研究结果如下:(1)从污泥厌氧酸化混合液中分离提取有机酸的支撑液膜体系为:疏水聚丙烯微滤膜、三烷基氧膦、磺化煤油和碳酸氢钠。(2)少量磺化煤油对污泥产酸有较明显的促进作用,与对照样相比,磺化煤油的添加量为1/32时,总酸和乙酸的产量分别提高20%左右。而过多的磺化煤油对产酸的促进作用不明显。(3)支撑液膜法提取模拟污泥酸化混合液中有机酸最适条件为:给液相有机酸浓度为20g/L,萃取剂浓度为3%,膜组件高径比为10:1,反萃取相pH值为9,反萃取剂为NaHCO3,反萃取剂浓度为30g/L,提取温度为30℃,提取时间为360min,浓缩倍数为2.0。此时,有机酸的萃取率可达85.0%。(4)支撑液膜法提取实际污泥酸化混合液中有机酸时,总有机酸和乙酸的提取率分别为69.0%和65.0%,乙酸和总酸的浓缩效率分别是1.3和1.4倍。更多还原

【Abstract】 The components of anaerobicly acidified broth of sludge are unexpected due to the complexity of municipal sludge with toxic inorganic or organic substances. The separation of organic acids from anaerobicly acidified broth of sludge could avoid the product inhibition and improve the efficiency and rate of sludge conversion to organic acids. The study of the separation of organic acids is of significance. The supported liquid membrane combines the solvent extraction and membrane separation with many advantages, such as high separation efficiency, low energy consumption and concentration of organic acids. This main investigation of this thesis includes: the selections of the appropriately membrane modules, solvent and extractant etc.; the optimization of operating conditions of supported liquid membrane. The major results are summarized as follows:(1)The supported liquid membrane is composed of hydrophobic PP microfiltration, trialkyl phosphine oxide, sulfonated kerosene and NaHCO3.(2)The volatile fatty acids production was improved by a slight amount of sulfonated kerosene while the effect was not clear by lots of sulfonated kerosene. The production was improved by 20% with 1/32 sulfonated kerosene.(3)The optimal conditions of the extraction of organic acids were as follows: the concentration of organic acids in feed was 20 g/L, the concentration of extractant was 3 %, the ratio of length to diameter for membrane module was 10:1, the stripping phase pH was 9, the stripping agent was NaHCO3, its concentration was 30 g/L, the extraction temperature was 30℃, the extraction time was 360min, the concentrate efficiency was 2.0. The total extraction efficiency amounted to 85.0%.(4)The extraction efficiency of total acids and acetic acids were 69.0% and 65.0% respectively, while the concentrate efficiency was 1.3 and 1.4.更多还原