城市污泥过热蒸汽干燥冷凝液特性研究
发布时间：2019-06-10 04:44
【摘要】：随着我国经济曲线的快速上升,城镇化进程的不断加快,越来越多的工业废水和城镇污水需要排放,同时污泥的产量也随之升高。污泥具有含水率高、体积庞大等特点,而且还含有大量的微生物和重金属等有毒有害物质。如果不能对污泥进行无害化和减量化处理,势必对人类的生存环境造成威胁。传统的污泥处理处置方式是填埋、堆肥、焚烧等,但是无论采用何种方法,处理污泥的关键一步就是降低其含水率。过热蒸汽干燥技术是近年来发展的新兴技术,与传统的热风干燥相比具有能耗低、干燥品质好和安全隐患小等优点。在使用过热蒸汽干燥的过程中,尾气中含有大量的水蒸气和污染物质,而这些尾气可通过降温冷凝的方式作为预处理,这样便减少尾气排出的体积,提高后续处理的达标排放效率。本文主要研究的内容是采用过热蒸汽为干燥介质,对污泥在不同温度下连续干燥所收集的冷凝液进行水质和有机物分析。为此搭建了污泥过热蒸汽干燥实验系统来收集各个温度下的冷凝液。整个实验系统包括蒸汽发生系统、加热系统、干燥系统、冷凝系统和其他装置,按照实验要求,完成对相关部件及设备的设计和选型,干燥系统整体结构紧凑,安全可靠。本文研究了在180℃、220℃、260℃三个温度阶梯连续干燥污泥的过程中,对污泥冷凝液的水质及有机物分析,通过测定冷凝水中的PH值、浊度、COD值、BOD5、NH_4~+-N等水质变化和有机物的气相色谱—质谱,其分析结果如下:(1)污泥在干燥的过程中,收集到的冷凝液中-N和酸类物质形成一个缓冲体系,使得PH值的变化范围在5.59~6.39之间。(2)在三个温度连续干燥下,180℃温度下收集的冷凝液的COD值最小,而在220℃干燥下的冷凝液的COD值最大,说明污泥中一些有机物需要达到一定的温度才会挥发出来。随着干燥温度的升高,对冷凝液中可生化降解的物质影响并不大。(3)随着温度的升高,冷凝液的-N浓度呈上升趋势,而且冷凝液中的浊度值也由在温度180℃干燥下的25.2NTU上升至260℃干燥下的123NTU。(4)收集到的冷凝液中物质成分较复杂,在温度180℃和220℃连续干燥条件下,冷凝液中有机物的主要成分以醇类物质为主;在260℃温度干燥下,其主要的有机组分为醛类。
[Abstract]:With the rapid rise of China's economic curve and the acceleration of urbanization, more and more industrial wastewater and urban sewage need to be discharged, and the output of sludge also increases. Sludge has the characteristics of high moisture content, large volume, and also contains a large number of microorganisms and heavy metals and other toxic and harmful substances. If the sludge can not be innocuous and reduced, it is bound to pose a threat to the living environment of human beings. The traditional sludge treatment and disposal methods are landfill, composting, incineration and so on, but no matter what method is adopted, the key step of sludge treatment is to reduce its moisture content. Superheated steam drying technology is a new technology developed in recent years. Compared with the traditional hot air drying, superheated steam drying technology has the advantages of low energy consumption, good drying quality and low safety risks. In the process of using superheated steam to dry, the tail gas contains a large amount of water vapor and pollution substances, and these exhaust gases can be pretreated by cooling and condensation, thus reducing the volume of exhaust gas discharge. Improve the discharge efficiency of follow-up treatment. The main content of this paper is to analyze the water quality and organic matter of condensate collected by continuous drying of sludge at different temperatures by using superheated steam as drying medium. For this reason, an experimental system of sludge superheated steam drying was set up to collect condensate at various temperatures. The whole experimental system includes steam generation system, heating system, drying system, condensation system and other devices. According to the experimental requirements, the design and selection of related components and equipment are completed. The overall structure of the drying system is compact, safe and reliable. In this paper, the water quality and organic matter of sludge condensate were analyzed in the process of continuous drying sludge at 180 鈩，
本文编号：2496180
[Abstract]:With the rapid rise of China's economic curve and the acceleration of urbanization, more and more industrial wastewater and urban sewage need to be discharged, and the output of sludge also increases. Sludge has the characteristics of high moisture content, large volume, and also contains a large number of microorganisms and heavy metals and other toxic and harmful substances. If the sludge can not be innocuous and reduced, it is bound to pose a threat to the living environment of human beings. The traditional sludge treatment and disposal methods are landfill, composting, incineration and so on, but no matter what method is adopted, the key step of sludge treatment is to reduce its moisture content. Superheated steam drying technology is a new technology developed in recent years. Compared with the traditional hot air drying, superheated steam drying technology has the advantages of low energy consumption, good drying quality and low safety risks. In the process of using superheated steam to dry, the tail gas contains a large amount of water vapor and pollution substances, and these exhaust gases can be pretreated by cooling and condensation, thus reducing the volume of exhaust gas discharge. Improve the discharge efficiency of follow-up treatment. The main content of this paper is to analyze the water quality and organic matter of condensate collected by continuous drying of sludge at different temperatures by using superheated steam as drying medium. For this reason, an experimental system of sludge superheated steam drying was set up to collect condensate at various temperatures. The whole experimental system includes steam generation system, heating system, drying system, condensation system and other devices. According to the experimental requirements, the design and selection of related components and equipment are completed. The overall structure of the drying system is compact, safe and reliable. In this paper, the water quality and organic matter of sludge condensate were analyzed in the process of continuous drying sludge at 180 鈩，
本文编号：2496180
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