柠檬酸生化污泥的理化特性与热解特性研究

Physicochemical and Pyrolysis Characteristics of Citric Acid Biochemical Sludge

本文对柠檬酸生化污泥的理化性质和热解特性进行了分析,主要利用扫描电镜(SEM)、傅里叶红外光谱仪(FT-IR)、热重分析仪(TGA)、热解-气质联用仪(Py-GC-MS)及其他分析方法对污泥的表面形貌、官能团种类、热解失重规律及快速热裂解产物组成等特性进行了研究。实验结果表明,柠檬酸好氧污泥具有较高的灰分和较低的挥发分,厌氧污泥固定碳和碳元素含量较高;干化污泥表面结构密实,有机质与无机填料紧密包覆,呈片状或层状分布;污泥热失重可以分为水分析出(200℃以下)、有机物质析出(200~500℃)和无机矿物质分解(500~800℃)三个阶段,在315℃左右出现最大失重峰,有机质热分解特性显著;Py-GC-MS分析表明,柠檬酸生化污泥快速热裂解产物类型复杂,主要包括芳环类化合物、含氮化合物、醛酮化合物、醇类、羧酸和酯类化合物等。

Proximate analysis and element composition of citric acid biochemical sludge were analyzed,and the surface morphology,functional group types,pyrolysis characteristics and thermal cracking composition of the sludge were studied by SEM,FT-IR,TG-DTG and Py-GC-MS,respectively.The results show that aerobic sludge has higher ash content and lower volatile content,while anaerobic sludge has higher fixed carbon and C content.The surface structure of all dried sludge are dense,due to the inorganic fillers are combined tightly with organic matter,showing a flake or block shape.The sludge pyrolysis can be divided into three stages:water volatilization stage(below 200℃),organic pyrolysis stage(200~500℃)and mineral decomposition stage(500~800℃).And a maximum weight loss peak appeared around 315℃,which indicates that the pyrolysis characteristics of organic matter in the sludge are obvious.Py-GC-MS showed that the various thermal cracking products mainly include aromatic compounds,nitrogen-containing compounds,alcohols,ester compounds,carboxylic acids,etc.