餐厨垃圾乙醇—甲烷耦联发酵过程中参数的优化及微生物群落变化研究

论文摘要

餐厨垃圾排放量大,有机物含量高,中国每年大约产生6000万吨的餐厨垃圾,对其进行有效处理意义重大。与传统的垃圾处理方法（包括填埋、焚烧和堆肥）相比,厌氧发酵技术由于可以回收能源,被视为一种有前途的餐厨垃圾处理技术。餐厨垃圾乙醇发酵具有反应时间短,产物易运输的优点,但是产生大量难以处理的乙醇糟液。糟液未经适当处理排放,将对水资源和土壤造成严重污染。而高浓度糟液废水处理成本高,因此寻找合适的技术从糟液废水进行资源化和能源化的回收十分重要。本研究通过构建餐厨垃圾乙醇-甲烷耦合发酵系统,利用乙醇糟液进行甲烷发酵,对影响该过程的重要因素进行分析,同时确定微生物群落的动态变化规律并探讨其与过程性能之间的关系,研究了不同方法对糟液进行预处理,进而回流发酵产乙醇,对比分析其对乙醇发酵的影响。利用生命周期评价法对全过程进行了污染排放和能源消耗分析。结果表明,餐厨垃圾乙醇-甲烷耦合发酵系统可以在20天内将乙醇废液完全消化,甲烷累积产量约为569 mL/g vs。氨氮浓度对耦合系统中甲烷的生成有明显的抑制作用。采用铵离子脱除实验研究对甲烷发酵的影响,分别在厌氧前加入氢氧化镁,采用磷酸铵镁（MAP）沉淀,在厌氧期间使用氢氧化镁,氨氮脱除率均高于80%。生化甲烷电位测试（BMP）表明,pH和温度对乙醇废水中甲烷的生成起着重要的控制作用。在55℃和pH 7条件下,可以获得最高产量为164 mL/g vs。耦合发酵体系微生物群落表明,在属和门水平上,产氢菌是整个发酵过程中的优势种。古生菌产甲烷菌（醋酸产甲烷菌）的存在有助于利用醋酸和氢生产甲烷。乳酸菌种类（乳球菌）在乙醇反应器中占主导地位,这表明餐厨垃圾容易产生乳酸积累。耦合发酵系统中,大量的氨、盐和挥发性脂肪酸（包括高乙酸盐）可以促进醋酸盐氧化途径。运用不同处理方法对乙醇糟液进行了处理获得出水进行乙醇发酵,结果表明,利用电渗析废水和微生物燃料电池废水缩短发酵时间50%,乙醇最高浓度47 g/L。在发酵系统中发现的最高乳酸为15 g/L,甲酸最高为11 g/L。VFA的存在对乙醇发酵系统无明显抑制作用。通过生命周期评价对乙醇-甲烷耦合发酵系统的分析表明,该工艺具有很高的GWP和AP排放。比较来看,甲烷阶段比乙醇阶段有更高的GWP和AP排放。而乙醇的POCP排放量比甲烷多。

论文目录

• Acknowledgement
• 摘要
• Abstract
• List of Abbreviations and Symbols
• 1 Introduction
•   1.1 Statement of the problem
•   1.2 Research objectives
•   1.3 Organization of the research and overview
•   1.4 Novelty statement
• 2 Literature review
•   2.1 Food waste treatment and status
•   2.2 Ethanol fermentation from food waste
•     2.2.1 Influencing factors on ethanol fermentation
•     2.2.2 Optimization of parameters and the chemical nutrient for ethanol fermentation
•   2.3 More values from stillage of ethanol fermentation
•     2.3.1 Stillage as feedstock
•     2.3.2 Stillage recycles fermentation in food waste （pros and cons）
•   2.4 Inhibition during stillage recirculation
•     2.4.1 Organic acids accumulation inhibition
•     2.4.2 Sodium chloride accumulation inhibition
•     2.4.3 Osmotic stress inhibition
•   2.5 Methane fermentation from stillage
•     2.5.1 Characteristics of stillage influence anaerobic digestion
•     2.5.2 Optimization of methane fermentation parameters
•   2.6 Ethanol-methane coupling fermentation from FW
•     2.6.1 Coupling fermentation challenge
•     2.6.2 Ammonium ions removal technologies
•   2.7 Microbial community structure in ethanol-methane coupling fermentation
•   2.8 Effect of recirculation of process water on ethanol production
• 3 Materials and Methods
•   3.1 Raw materials
•   3.2 Technology road map
•   3.3 Experimental procedure
•   3.4 Ethanol fermentation experiment:
•   3.5 Collection and preparation of recycled water, recycling in bioethanol production
•   3.6 Methane fermentation experiments:
•   3.7 Set up of optimization of methane fermentation parameters experiment
•     3.7.1 Determination of optimum initial pH
•     3.7.2 Determination of optimum temperature
•   3.8 Kinetic simulation
•   3.9 Chemical analysis:
•   3.10 Microbial community analysis in ethanol-methane coupling fermentation
•     3.10.1 DNA extraction and PCR magnified
•     3.10.2 Power soil DNA isolation kit protocol
•     3.10.3 Pyrosequencing and sequencing analysis
•   3.11 Ammonium ions removal experiment
•   3.12 Anew approach to LCA
• 4 Ethanol-methane coupling fermentation technology from food waste: challenge and stability
•   4.1 Characterization of the raw materials
•   4.2 Recovered ethanol and methane in the coupling fermentation
•   4.3 Effect of volatile fatty acids changes during AD of stillage
•   4.4 Effect of alkalinity and pH changes during AD of stillage
•   4.5 Effect of ammonium-nitrogen changes during AD of stillage
•   4.6 Ammonium ions removal from stillage reactor
•   4.7 Ethanol recovery from FW using effluent from methane fermentation
•   4.8 Material and COD distribution in the coupling fermentation model
•   4.9 Chapter summary
• 5 Optimization of methane significant parameters and Microbial community in ethanol-methane coupling fermentation model
•   5.1 Optimization of methane fermentation significant parameters
•     5.1.1 Characterization of stillage
•     5.1.2 The effect of initial pH on methane production
•     5.1.3 The effect of reactor temperature on methane production
•   5.2 Microbial community in two stages of coupling fermentation
•     5.2.1 Potential of SAO pathway application
•     5.2.2 Bacterial community structure at genus level
•     5.2.3 Bacterial community structure at phylum level
•     5.2.4 Archaeal community structure at genus level
•     5.2.5 Archaeal community structure at phylum level
•   5.3 Chapter summary
• 6 Assessment of bioethanol fermentation performance using different recycled water of an integrated system based- food waste
•   6.1 Properties of process water and food waste
•   6.2 Performance of ethanol fermentation via methane left water
•   6.3 Performance of ethanol fermentation via electrodialysis left water
•   6.4 Performance of ethanol fermentation via MFC left water
•   6.5 The potential inhibition effects of volatile fatty acids on ethanol fermentation
•   6.6 Influence of fermentation time on ethanol yield and productivity
•   6.7 Chapter summary
• 7 Environmental impact of ethanol-methane coupling fermentation model
•   7.1 Background
•   7.2 System description
•     7.2.1 Goal and scope definition
•     7.2.2 Inventory data
•     7.2.3 Functional unit
•     7.2.4 System boundaries
•   7.3 Characterization results for ethanol-methane fermentation
•   7.4 Chapter summary
• 8 Conclusions and Future perspectives
•   8.1 Conclusions
•   8.2 Future perspectives
• References
• 作者简历及在学研究成果
• 学位论文数据集

文章来源

类型: 博士论文

作者: Mashair Anwar Saeed（玛莎尔）

导师: 汪群慧,马鸿志

关键词: 乙醇甲烷耦合系统,餐厨垃圾,发酵参数优化,微生物群落

来源: 北京科技大学

年度: 2019

分类: 基础科学,工程科技Ⅰ辑

专业: 生物学,环境科学与资源利用,环境科学与资源利用

单位: 北京科技大学

基金: the International Science&Technology Cooperation Program of China(2013DFG92600),the NationalScientific Funding of China(51008020,51378003)

分类号: X172;X799.3

总页数: 118

文件大小: 7196K

下载量: 206