不同浓度猪、奶牛粪水中温厌氧发酵沼液中DOM的光谱特征

Fluorescence Spectra Characteristics of Dissolved Organic Matter in Mesophilic Anaerobic Digestion of Pig and Dairy Manure Slurries

养殖粪水中物质的组成变化决定其潜在的环境效应,溶解性有机质(DOM)是养殖粪水的重要组成部分。研究对总固体浓度(TS)分别为4%和8%的猪、奶牛粪水进行批次中温厌氧发酵试验,分析了猪粪和奶牛粪沼液中DOM的含量变化,并结合三维荧光光谱(3DEEM)和平行因子分析法(PARAFAC),解析沼液DOM的荧光光谱特性及组分变化特征。结果表明,中温厌氧发酵结束后,沼液中DOM含量均极显著(p<0.001)降低。沼液DOM主要包含类酪氨酸、类富里酸、类色氨酸和类胡敏酸4种荧光组分,其中类胡敏酸的相对含量均显著(p<0.05)增加,但类富里酸的相对含量仅在TS为8%的处理中增加,而在TS为4%的处理中降低。沼液DOM的腐殖化指数均极显著(p<0.01)增加,但猪粪沼液DOM的腐殖化程度明显高于奶牛粪沼液。研究结果为畜禽粪便沼液农田利用的潜在环境效应评价提供理论支撑。

The potential environmental effects of fecal water are determined by the composition changes of substances.Dissolved organic matter(DOM)is an important component of fecal water.In this study,the content of DOM in pig and dairy manure slurries was analyzed by batch mesophilic anaerobic fermentation with a total solid concentration(TS)of 4%and 8%,respectively.DOM’s fluorescence spectrum characteristics and component variation characteristics in raw and digested slurries were analyzed by three-dimensional fluorescence spectroscopy(3DEEM)and parallel factor analysis(PARAFAC).After mesophilic anaerobic fermentation,there sults showed that DOM content in slurries decreased significantly(p<0.001).DOM of manure slurries mainly contained four fluorescent components:tyrosine like,fulvic acid like,tryptophan like and humic acid like.The relative content of humic acid increased significantly(p<0.05),but the relative content of fulvic acid increased only in the treatment of TS=8%but decreased in TS=4%.The humification index of DOM in digested slurries increased significantly(p<0.01),but the humification degree of DOM in pig manure slurries was significantly higher than that in dairy manure slurries.The results can provide theoretical support for evaluating potential environmental effects of livestock manure slurries utilization in farmland.