污泥厌氧消化过程腐殖质表征及其演变研究

发布时间：2018-04-14 18:41

本文选题：腐殖质 + 剩余污泥　；参考：《北京建筑大学》2017年硕士论文

【摘要】：《巴黎气候协定》签署将低碳发展提升到政治高度。各国随之出台一系列碳减排计划。“碳中和”运行已成为未来污水处理厂发展的主要方向。污水处理过程产生的剩余污泥蕴含大量潜在有机能源,而污泥厌氧消化是转化污泥有机质为能源的重要途径。然而,污泥厌氧消化存在着污泥细胞破壁困难、含难降解木质纤维素和腐殖质成分等问题,往往导致污泥厌氧消化效率不高。其中,腐殖质非但难以生物降解,反而因其结构中羧基、酚羟基与水解酶结合而可致其它有机物水解效率降低。腐殖质结构复杂,预处理手段可能难以完全破坏其复杂结构,并不能在根本上消除它对厌氧消化的抑制作用,而原位钝化腐殖质含氧官能团方有可能奏效。腐殖质抑制厌氧消化水解程度与解抑制策略取决于腐殖质含量与结构特征。为此,本课题分析污泥厌氧消化过程腐殖质(胡里酸HA与富里酸FA)含量与结构特征变化,为制定解抑制技术策略提供研究基础。实验首先考察无腐殖质人工配水生成剩余污泥(人工配泥)厌氧消化过程中HA与FA含量与结构特征变化。分析结果显示,HA与FA厌氧消化前含量为370和190 mg/L,腐殖质(HA+FA)占污泥总固体(TS)质量分数的2.8%;厌氧消化后两者分别增加至390和200 mg/L,腐殖质占TS质量分数增至3.5%。紫外光谱与红外光谱分析表明,HA与FA厌氧消化后其结构组成中脂肪族化合物减少,而芳香族化合物提高,且FA结构组成中脂肪族化合物有消失迹象。含氧官能团分析揭示,相较厌氧消化前,HA与FA厌氧消化后各自羧基与酚羟基含量均增加;HA与FA在厌氧消化过程羧基与酚羟基含量和均在4.07~5.97 mmol/g范围之内。第二阶段实验分析了实际污水厂污泥厌氧消化过程HA与FA各自含量与结构特征变化。分析结果显示,液相中HA与FA含量均得到增加,两者厌氧消化前含量分别是29和139 mg/L,厌氧消化后增加至43和200 mg/L,分别增加48.3%和43.9%;固相HA与FA含量在厌氧消化过程始终呈现降低趋势,厌氧消化前分别是1 133和242mg/L,厌氧消化后两者降低至1 057和143 mg/L,分别减少6.7%和40.9%;系统中腐殖质含量(HA+FA)在整个厌氧消化过程亦呈现降低趋势,由厌氧消化前1 543 mg/L降低至1 443 mg/L,减少6.5%。紫外光谱、红外光谱、含氧官能团分析表明,HA与FA厌氧消化过程朝着腐殖质化程度加深、芳香度提高以及含氧官能团增加方向演变。二维红外光谱分析揭示,固、液两相中HA与FA在厌氧消化过程其结构组成中均存在先以脂肪族化合物组分变化,而后羧酸盐物质与多糖组分变化的次序。
[Abstract]:The signing of the Paris Climate Agreement raised low-carbon development to a political level.Countries then issued a series of carbon emission reduction plans.Carbon neutralization has become the main direction of future sewage treatment plant development.The excess sludge produced in the process of sewage treatment contains a large amount of potential organic energy, and anaerobic digestion of sludge is an important way to transform sludge organic matter into energy.However, sludge anaerobic digestion is difficult to break down the wall of sludge cells, and it is difficult to degrade lignocellulose and humus, which often leads to the low efficiency of sludge anaerobic digestion.The humus is difficult to biodegrade, but the hydrolysis efficiency of other organic compounds can be reduced because of the combination of carboxyl group, phenolic hydroxyl group and hydrolase in its structure.The complex structure of humus may not be completely destroyed by pretreatment, and the inhibition of anaerobic digestion can not be eliminated fundamentally. However, the in situ passivation of oxygen-containing functional groups of humus may be effective.The degree of anaerobic digestion and hydrolysis of humus inhibition and the decompression strategy depend on the content and structure of humus.Therefore, the content and structural characteristics of humus (HA and FAA) in sludge anaerobic digestion process were analyzed in this paper.The changes of HA and FA contents and structural characteristics during anaerobic digestion of excess sludge (artificial sludge) produced by artificial water distribution without humus were investigated.The results showed that the contents of HA and FA before anaerobic digestion were 370 mg / L and 190 mg / L, and the content of humus HA / FA was 2.8% of the total solid sludge TSN, and after anaerobic digestion they increased to 390 mg / L and 200 mg / L, respectively, and the ratio of humus to TS increased to 3.5 mg / L.UV and IR spectra showed that the fatty compounds in HA and FA decreased, while the aromatic compounds increased, and the aliphatic compounds in FA showed signs of disappearance after anaerobic digestion.The results of functional group analysis showed that the contents of carboxyl and phenolic hydroxyl in HA and FA increased in the range of 4.07 ~ 5.97 mmol/g during anaerobic digestion.In the second stage, the content and structure characteristics of HA and FA in the anaerobic digestion process of sewage sludge were analyzed.The results showed that the contents of HA and FA in liquid phase were increased.Before anaerobic digestion, the contents of HA and FA were 29 mg / L and 139 mg / L, respectively, and increased to 43 and 200 mg / L after anaerobic digestion, which increased by 48.3% and 43.9%, respectively, while the contents of HA and FA in solid phase decreased during anaerobic digestion.Before anaerobic digestion, it was 1 133 and 242 mg / L, respectively. After anaerobic digestion, both of them decreased to 1 057 and 143 mg / L, which decreased by 6. 7% and 40. 9%, respectively. The humus content and HA FAA in the system also showed a decreasing trend during the whole anaerobic digestion process.From 1 543 mg/L before anaerobic digestion to 1 443 mg / L, a decrease of 6. 5%.Ultraviolet spectrum, infrared spectrum and oxygen functional group analysis showed that the anaerobic digestion process of HA and FA evolved towards humic degree, aromaticity increase and oxygen functional group increasing.Two-dimensional infrared spectroscopy revealed that the structure and composition of HA and FA in both solid and liquid phases changed firstly in the anaerobic digestion process, then in the carboxylate and polysaccharide components.
【学位授予单位】：北京建筑大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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