【作者】 王莉；

【导师】 马广大；

【作者基本信息】 西安建筑科技大学 ， 环境工程， 2004， 硕士

【摘要】 生物法净化挥发性有机气体是近年来发展的新工艺。本试验采用生物过滤法，选取乙苯为代表物，选取陶粒做填料，并对微生物进行培养、驯化、筛选，最终得到优势菌种，并把它们接种到填料中挂膜，降解有机物乙苯。 试验结果表明：生物过滤床降解乙苯废气的效率与填料床层的高度有关，填料床层越高，降解效率越高；乙苯废气的浓度随填料床层的升高而降低。但床层越高，压降越大，成本越大。生物过滤塔对低浓度和中等浓度的乙苯废气降解效率较高，而对高浓度降解效果不理想。乙苯废气流量越大，停留时间越短，流量越小，停留时间越长；当停留时间长时，微生物有足够的时间去吸附降解有机物，净化效率高。入口段的填料层单元体积去除负荷最大，而出口段的填料层单元体积去除负荷最小，填料的体积去除负荷随填料层高度的增加而降低，这是因为入口段填料层中营养物质较为丰富，生物膜较厚的缘故。填料的比表面积越大，空隙率越高，去除效率越高。填料的空隙率越小，随着填料表面生物膜的生长和积累，填料易发生堵塞，喷淋液无法通过填料层，使得填料层压降很大。二氧化碳轴向浓度随乙苯轴向浓度的减少而增加。填料湿度在30％～50％间较好。表面活性剂的加入有利于有机物的降解．本试验中微生物工作的最佳pH值为7左右，微生物在25℃时工作状态最佳。更多还原

【Abstract】 Biotreatment of VOCs is a nearly developed method.This paper is finished based on the biofiltration. In the experiment the ethylbenzene is selected as the agent and the pellets as filters,we cultivated ,acclimatized and screened the germs and then we got dominant species and inoculated them into filter to grow membranes so that the ethybenzene can be degradated.The results show that the ethylbeneze degradation efficiency is related to the filter’s altitude. The higher the filter is, the better the efficiency is, and the ethylbenzene concentration becomes lower. However, the higher the filter is, the more obvious the pressure drop is ,and the cost becomes more. The biofiltration degradation efficiency has good results in low ethylbenzene concentration and medium ethylbenzene concentration. But to higher concentration the results are not as good as the lower ones and medium ones. The higher the flow is, the shorter the residence time is, and vice versa. When the residence time is long, the germs have enough time to degrade and absorb VOCs, So the efficiency is high. Usually,the inlet volume removal load is maximum and the outlet volume removal load is minimum. The filter’s volume removal is lower with the filter’s higher attitude. The reason is that the inlets have thicker biological membranes. The greater the specific surface areas and the higher the porosites the pellets have , ,the better the degradation efficiencies are ,and vice versa. With the biological membranes’growth and accumulation ,it is easy for the filters to be clogged and the sprinkling can’t pass through the filters. In result, the pressure drop becomes bigger and bigger .Carbon dioxide concentration becomes bigger with ethylbeneze’s biological degradation; and the moisture is within 30%-50% .Surfactant is beneficial to the degradation .The best working conditions are that pH is 7 and the temperature is 25 C.更多还原