Impact of Salinity on Lactic Acid Production from Co-ferment

发布时间：2024-02-01 14:10

　　近年来,将餐厨垃圾和剩余污泥进行生物发酵产生乳酸等高附加值的化学品越来越受到关注。乳酸是一种重要的工业中间体,被广泛用作生物可降解塑料(聚乳酸)的前驱体。餐厨垃圾和剩余污泥的联合发酵不仅有利于有机废弃物的资源化利用,而且有利于提高发酵产品的价值。研究发现,剩余污泥中存在大量的微生物,对乳酸发酵有促进作用。值得注意的是,餐厨垃圾中盐的含量约为2%-5%。餐厨垃圾中存在的盐可能会影响乳酸菌,而乳酸发酵过程中尚未对其进行研究。本研究的目的是研究盐(NaCl)对发酵产乳酸的影响,并说明盐对乳酸发酵途径的影响。主要结果如下:首先,研究了NaCl浓度对乳酸产生的影响。实验结果表明,乳酸的产生与NaCl的浓度有关。用0、5、10、15、20、25、30、40和50 g/L不同浓度的NaCl进行了3次批次实验,分别标记为空白,NaCl-5、NaCl-10、NaCl-15、NaCl-20、NaCl-25、NaCl-30、NaCl-40和Na CL-50。第1次批次实验在NaCl-25组发酵第四天时,乳酸最大浓度为35.23 g COD/L,其光学活性为84.13%;第2次批次实验在NaCl-25组发酵第...

【文章页数】：64 页

【学位级别】：硕士

【文章目录】：
摘要
ABSTRACT
Chapter1 Introduction
    1.1.Sources and characteristics of food waste and waste activated sludge
        1.1.1.Food waste
        1.1.2.Waste activated sludge
    1.2.Treatment of food waste and waste activated sludge
        1.2.1.Food waste treatment methods
        1.2.2.Waste activated sludge treatment methods
    1.3.Lactic acid production by co-fermentation of food waste and WAS
        1.3.1.Characteristics and applications of Lactic acid
        1.3.2.Technology of lactic acid production by co-fermentation of food waste and excess sludge
        1.3.3.The research progress of lactic acid production by co-fermentation of food waste and excess sludge
    1.4.Application of salt on fermentation and microbial community
    1.5.Source and significance of the project
        1.5.1.Subject source
        1.5.2.Research significance
        1.5.3.Research objectives
        1.5.4.Research content
        1.5.5.Technical route
Chapter2 Material and Methods
    2.1.Experimental materials
        2.1.1.Food waste and waste activated sludge
        2.1.2.Experimental instruments
    2.2.Test items and analysis methods
        2.2.1.Sample pretreatment method
        2.2.2.Determination of lactic acid
        2.2.3.VFA determination
        2.2.4.Determination of soluble carbohydrate and protein
        2.2.5.Determination of enzymes
        2.2.6.Microbial community and predictive functional profiles analysis
        2.2.7.Determination of other indicators
Chapter3 Impact of Salt on Lactic Acid Production
    3.1.Experimental conditions
    3.2.1^st Batch
        3.2.1.The Effect of Salt on Production of L-lactate and D-lactate
        3.2.2.The Effect of Salt on Production of total lactate and OA of L-lactate
    3.3.2^nd Batch
        3.3.1.The Effect of Salt on Production of L-lactate and D-lactate
        3.3.2.The Effect of Salt on Production of total lactate and OA of L-lactate
    3.4.3^rd Batch
        3.4.1.The Effect of Salt on Production of L-lactate and D-lactate
        3.4.2.The Effect of Salt on Production of total lactate and OA of L-lactate
    3.5.Comparison of all batches
Chapter4 Impact of Salt on Fermentation Process
    4.1.Effect of Salt on Solublization
        4.1.1.Changes in SCOD and VSS in Fermentation Systems
    4.2.Effect of salt on hydrolysis
        4.2.1.Change in enzymatic activity by salt dosage
        4.2.2.Effect of Na Cl on fermentation from NH4+-N concentration
    4.3.Effect of salt on glycolysis
        4.3.1.Changes in soluble carbohydrates in fermentation systems
    4.4.Effect of Salt on VFA Production
    4.5.Conclusion of Chapter 4
Chapter5 Analysis of Microbial Communities in Fermentation System
    5.1.Microbial community abundance
    5.2.Analysis of the differences in the composition of microbial community taxonomy
    5.3.Functional gene
Chapter6 Conclusion
    6.1.Effects of salt on lactic acid production
    6.2.Effects of salt on metabolism
    6.3.Effects of salt on microbial community
PUBLICATIONS
ACKNOWLEDGEMENTS
REFERNCES



本文编号：3892252