表面活性剂烷基糖苷促进活性污泥发酵生产短链脂肪酸的研究
时间:2018-03-07 10:11 来源:毕业论文 作者:毕业论文 点击:次
| 摘要在厌氧反应器中对比研究了两种生物表面活性剂烷基糖苷（APG）以及鼠李糖脂（RL）对剩余活性污泥水解产酸的影响。实验结果表明，表面活性剂APG和RL的投加均能促进污泥中短链脂肪酸产量的提高。在发酵时间3d，APG投加量为0.4g/g TSS时，最大产酸量为2766mg/L；发酵时间为4d，RL投加量为0.1g/g TSS时，最大产酸量为2639mg/L，而空白组最大产酸量仅为1200mg/L。污泥水解过程中，SCOD、蛋白质和可溶性糖的浓度均呈现先增加后降低的趋势，揭示了表面活性剂促进污泥水解产酸的机理在于降低污泥表面张力，加强污泥中有机物溶出，加快污泥水解阶段，从而提高污泥产酸量。此外，APG在污泥体系存在自身降解作用，短链脂肪酸（SCFAs）一部分来源于APG的降解，而RL的自身降解对短链脂肪酸（SCFAs）产量的贡献很小。实验结果表明，APG和RL均能使剩余污泥厌氧发酵过程中的SCFAs得以大量积累。19344 关键词： 剩余污泥，烷基糖苷，鼠李糖脂，短链脂肪酸 Title Short-chain fatty acids production from waste-activated sludge improved in the presence of surfactant alkyl poly glucosides Abstract In this work, the influence of two biosurfactants alkyl poly glucosides (APG) and rhamnolipid (RL) on the short-chain fatty acids (SCFAs) accumulation of waste activated sludge (WAS) was investigated in the anaerobic reactors. Results showed that the SCFAs was improved by the both two biosurfactant APG and RL. At fermentation time of 3 days, the maximum total VFAs was 2766 mg/L with APG dosage of 0.4g/g TSS, and at fermentation time of 4 days, the maximum total VFAs was 2639 mg/L with RL dosage of 0.1g/g TSS, were both higher than the blank test (1200 mg/L). It was found that the two biosurfacants could greatly reduce the surface tension of sludge，accelerating the solubilization of organic solid and the hydrolysis．During the hydrolysis process，the concentrations of SCOD， soluble carbohydrate and soluble protein showed an obvious increase in the initial and then decrease late. These results suggested that the two biosurfactants could both greatly reduce the surface tension of sludge hydrolysis liquid, resulting in the solubilization of organic solid and the accumulation of SCFAs. Meanwhile, the biodegradation of APG during the whole fermentation time indicated that a fraction of SCFAs was from the hydrolysis of APG, the biodegradation of RL showed little effect to the accumulation of SCFAs. It was revealed that the SCFAs production was remarkably improved in the presence of APG and RL. Keywords: waste activated sludge, alkyl poly glucosides, rhamnolipid, short-chain fatty acids 目 次 1 绪论 1 1.1 研究背景和意义 1 1.2 污泥厌氧消化技术原理及影响因素 1 1.2.1 厌氧消化技术原理 1 1.2.2 厌氧消化的影响因素 2 1.3 加快污泥产酸速率的方法 4 1.3.1 热处理 4 1.3.2 生物法 4 1.3.3 化学法 5 1.3.4 机械法 5 1.4 表面活性剂的种类及应用 5 1.4.1 表面活性剂的性质和种类 5 1.4.2 表面活性剂的应用 6 1.4.3 生物表面活性剂 7 1.5 本课题的目的和意义 7 1.6 本课题的研究内容 8 2 实验过程 9 2.1 材料与方法 9 2.1.1 实验用泥 9 2.1.2 实验药品 9 2.1.3 实验仪器与设备 9 2.2 实验操作 10 (责任编辑：qin) |