城市污泥DOM的光谱特征及对氧化钙处理的响应

Spectral Characteristics of Municipal Sludge DOM and Its Response to Calcium Oxide Treatment

为了解碱预处理过程城市污泥中溶解性有机物(DOM)特征,揭示污泥调理的潜在机理,该研究采用三维荧光光谱技术结合平行因子分析法,深入探讨氧化钙处理前后不同城市污泥中DOM的结构变化。结果表明,CaO处理后pH值显著增大,污泥提取液溶解性有机碳(DOC)浓度和总荧光强度增大;三维荧光通过PARAFAC解析出3种组分:类色氨酸C1(280 nm/350 nm)、类富里酸C2(320 nm/380 nm)和类络氨酸C3(275 nm/300 nm),类蛋白质物质(C1+C3)是城市污泥主要成分;经CaO处理,从各组分荧光强度看,C1、C2所占比例升高,C3所占比例降低;从吸收光谱来看,SUVA_(254)、SUVA_(260)减小,E2/E3增大,表明污泥提取液中DOM的芳香性减弱,疏水性有机质含量减少,相对分子量减小;C1、C2、C3与DOM特征参数(SUVA_(254)、SUVA_(260)、E2/E3)及溶解性有机碳具有显著相关性。

In order to understand the characteristics of dissolved organic matter(DOM)in municipal sludge during alkaline pretreatment and reveal the potential mechanism of sludge conditioning,the article uses three-dimensional fluorescence spec⁃troscopy and PARAFAC to study the DOM structure of different municipal sludge before and after calcium oxide treatment.The results showed that the pH value increased significantly after CaO treatment,and the DOC concentration and total fluores⁃cence intensity of the sludge extract increased.EEM spectra analyzed by PARAFAC into three components:tryptophan-like C1(280 nm/350 nm),fulvic acid-like C2(320 nm/380 nm)and tyrosine-like C3(275 nm/300 nm),among which protein-like substances(C1+C3)are the main components of municipal sludge extract;the fluorescence intensities of C1 and C2 increases after CaO treatment,while the proportion of C3 decreases;SUVA_(254)and SUVA_(260)decreases and E2/E3 increases,indicating that the aromaticity of DOM in the sludge extract,the content of hydrophobic organic matter and the the relative molecular weight are all decreasing.C1,C2,C3 have significant correlation with DOM characteristic parameters(SUVA_(254),SUVA_(260),E2/E3)and dissolved organic carbon.