干化污泥在流化床内燃烧特性及污染物排放特性研究
发布时间：2018-07-15 15:28
【摘要】：随着我国经济技术的不断进步,工业废水和生活污水的排放逐年增加,这使得污水处理的剩余产物污泥也不断增加。污泥的性质极不稳定且含有许多有毒有害成分,会对环境和人类造成巨大危害。污泥焚烧是处理污泥最彻底的技术,而我国污泥焚烧技术发展还不成熟,缺乏全面可靠的试验数据,同时污泥焚烧处理的过程中也会产生各种污染物。因此本文将研究污泥焚烧特性及其污染物的排放与控制。首先,对污泥颗粒进行工业分析和元素测定,发现污泥中挥发分、灰分含量高,固定碳含量、热值较低;污泥中含有较多的N、S元素。在空气气氛中,利用热分析仪对干化污泥进行燃烧热重试验分析,重点考察升温速率对污泥燃烧特性的影响。发现污泥焚烧存在四个失重温度区间,分别在室温-120℃、200℃-400℃、400℃-550℃和650℃-950℃。根据Coats-Redfern法进行污泥燃烧动力学求解分析,得出最概然机理函数积分形式为G(α)=(1-α)-1-1。其次,在流化床试验台上,采用石英砂作为床料,研究污泥焚烧过程中不同燃烧温度,空气过量系数,钙硫比,FeCl3添加量对NOx、SO_2和HCl排放特性的影响。结果表明,焚烧温度对NOx的生成有促进作用,同时也会增加SO_2和HCl的排放,但当温度大于850℃时,SO_2增长趋势减弱。空气过量系数与NOx、SO_2生成正相关,但对HCl没有明显影响。增加钙硫比会促进NOx生成;对SO_2和HCl产生具有抑制作用,但去除效果不佳。FeCl3会同时增加NOx、SO_2和HCl的排放。最后,利用电感耦合等离子体原子发射光谱仪(ICP-OES)测定灰渣中Pb,Cr,Cd,Hg的含量来研究污泥在流化床内燃烧重金属迁移特性。结果表明,超过了95%的Hg在燃烧时随烟气排出,大多数Pb,Cr,Cd会富集到灰渣中。升高焚烧温度,延长焚烧时间都会减弱Pb,Cr,Cd在灰渣中残留。Pb挥发性较弱,在灰渣中残留率最高,Cd挥发性较强,在灰渣中残留率最低,而Cr会生成稳定的氧化物,受焚烧温度和焚烧时间的影响最小。
[Abstract]:With the development of economy and technology in China, the discharge of industrial wastewater and domestic sewage is increasing year by year. The nature of sludge is very unstable and contains many toxic and harmful components, which will cause great harm to the environment and human beings. Sludge incineration is the most thorough technology for sludge treatment. However, sludge incineration technology in China is still immature and lacks comprehensive and reliable experimental data. At the same time, various pollutants will be produced in the process of sludge incineration treatment. Therefore, the characteristics of sludge incineration and the discharge and control of pollutants will be studied in this paper. Firstly, the industrial analysis and elemental determination of sludge granules show that the sludge contains high volatile matter, high ash content, fixed carbon content and low calorific value, and the sludge contains more Nu S elements. In the air atmosphere, the combustion thermogravimetric test of dry sludge was carried out by means of thermal analyzer, and the effect of heating rate on the combustion characteristics of dry sludge was investigated. It is found that there are four weight-loss temperature ranges in sludge incineration, which are 400 鈩，
本文编号：2124536
[Abstract]:With the development of economy and technology in China, the discharge of industrial wastewater and domestic sewage is increasing year by year. The nature of sludge is very unstable and contains many toxic and harmful components, which will cause great harm to the environment and human beings. Sludge incineration is the most thorough technology for sludge treatment. However, sludge incineration technology in China is still immature and lacks comprehensive and reliable experimental data. At the same time, various pollutants will be produced in the process of sludge incineration treatment. Therefore, the characteristics of sludge incineration and the discharge and control of pollutants will be studied in this paper. Firstly, the industrial analysis and elemental determination of sludge granules show that the sludge contains high volatile matter, high ash content, fixed carbon content and low calorific value, and the sludge contains more Nu S elements. In the air atmosphere, the combustion thermogravimetric test of dry sludge was carried out by means of thermal analyzer, and the effect of heating rate on the combustion characteristics of dry sludge was investigated. It is found that there are four weight-loss temperature ranges in sludge incineration, which are 400 鈩，
本文编号：2124536
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