生物滴滤塔处理甲苯工艺过程的影响因素研究

采用陶粒为填料的生物滴滤塔降解甲苯,实验研究了浓度和气、液体流量对甲苯降解能力的影响,实验结果表明,随着气、液体流量的增大,净化效率降低。对影响气体进出口温差的因素和填料床内液膜温度分布的结果进行实测和分析发现：进口甲苯浓度和液体流量、气体进出口温差成正比,而与气体流量成反比。液膜在填料床内的温度分布是沿塔高先降低后升高。     

生物膜填料床内含有生化反应的多相传输模型

废气处理生物膜滴滤塔的多孔填料床内是带有气液两相流动、有机污染物扩散、生物膜内生化反应的复杂生化反应体系.在平行平板理论模型基础上,建立了生物膜多孔填料床内含生化反应的多元多相流动及传输特性的多相混合模型,获得了废气处理生物膜滴滤塔净化效率的理论计算方法.模型的理论预测值与生物膜滴滤塔净化低浓度甲苯废气的实验结果基本吻合.     

生物滴滤塔净化处理硫化氢的实验研究

在常温条件下,以陶粒和悬浮改性填料WD-F10-4为填料的生物滴滤塔系统对硫化氢废气进行净化处理,考察了不同硫化氢负荷、营养液喷淋量和气体停留时间对生物滴滤塔性能的影响。实验结果表明,当进气质量浓度为400 mg/m3,硫化氢负荷为32 g/(m3·h),喷淋量为4 L/h,气体停留时间为46 s,系统的平均去除效率为97%。系统运行期间,填料未出现堵塞现象,证明悬浮改性填料可用作生物滴滤塔的填料。     

生物法净化低浓度甲苯废气装置及其操作特性

对生物法净化低浓度甲苯废气的适宜装置及其操作特性的研究表明,生物膜填料塔对低浓度甲苯废气的净化性能优于筛板塔及鼓泡塔;生物膜填料塔采用逆流并在液气比0.03～0.1、气速（30～60）m·h~(-1)的条件下操作时,低浓度甲苯废气净化效率可保持在90％以上．经实验验证,本生物膜填料塔对废气中甲苯的同系物同样具有净化作用．并且对再生胶厂、印刷厂、铸造厂、油漆厂等企业的实际生产废气也有良好的净化效果．     

生物滴滤塔处理低浓度CS2废气的研究

将从生产CS2厂内的土壤中分离得到的硫杆菌固定在生物滴滤塔的填料上,组成生物滴滤塔反应系统,研究了入口CS2气体浓度、进气流量、喷淋量对CS2去除效率的影响。结果表明,在填料层高度420mm、停留时间50s、进口质量浓度低于800mg／m^3时,生化去除效率达90％以上。     

气液两相逆流状态下金属板波纹填料塔内液体流动分布

填料塔内液体流动分布状况直接关系到塔内气液两相的有效接触,影响塔的操作性能.由于液体分布不良,造成填料塔内局部区域的气液比与全塔宏观的气液比有显著差别,从而大大降低塔的总传质效率.因此,填料塔内的液体分布     

新型填料喷雾塔强化吸收甲醇废气的应用

甲醇作为化学工业基础原料和清洁液体燃料,长期接触会引起中毒。为了进一步的工业要求提供参考依据,文中采用了新型填料喷雾塔对含甲醇废气进行强化吸收的实验研究。通过改变液体流量、气体流量、甲醇进口质量浓度和温度单因子参数的方法观察甲醇的去除率和总吸收率,根据分析实验数据可知,当液气比与温度一定时,甲醇去除率和总吸收率随甲醇质量浓度增加而降低;当液气比与甲醇进口质量浓度一定时,两者随温度的升高呈缓慢上升趋势;当温度与液体流量一定时,甲醇去除率随着气体流量的增加而降低,而总吸收率随气体流量增加呈上升趋势;在气体流量一定时,两者都随液体流量的增加而增加。最后通过激光粒度分析仪测试该塔中4种不同高度喷雾液滴粒径分布。     

气液两相逆流状态下金属板波纹填料塔内液体流动分布

<正>填料塔内液体流动分布状况直接关系到塔内气液两相的有效接触,影响塔的操作性能.由于液体分布不良,造成填料塔内局部区域的气液比与全塔宏观的气液比有显著差别,从而大大降低塔的总传质效率.因此,填料塔内的液体分布     

生物膜填料塔净化二氧化硫废气初探

介绍生物法净化SO2 和其他含硫废气净化的原理及国内外近年的应用研究,对生物填料塔净化SO2 废气进行了初步的实验研究。结果表明,在温度为 20~25℃、循环液流量为 20L/h、气体流量为 0. 1~0. 3m3 /h、进气浓度为 500~5 000mg/m3 的条件下,应用先期培养驯化的硫细菌挂膜制作的生物膜填料塔对SO2 气体有较好的净化能力,净化效率达 90%以上,生化去除量可达 100mg/L·h。     

生物滴滤床净化挥发性有机物的研究进展

生物滴滤净化挥发性有机污染物技术是近年发展起来的一项新技术。文章介绍了生物滴滤技术的净化机理、净化效果的影响因素以及国内外研究现状。目前生物滴滤技术需要在以下几方面完善和发展:提高疏水性或难降解废气的处理能力,改进生物滴滤填料性能,提高对各运行参数的控制能力,加强实际废气的净化研究和完善生物滴滤模型。     

陶瓷球填料生物滴滤塔降解甲苯废气

The Purification experiments of waste gas containing low concentration toluene were made in trickling biofilter with ceramic spheres. The effects of liquid flow rate,gas flow rate,pH of circulation liquid, and toluene concentration in inlet gas on the purification efficiency of trickling biofilter were investigated. The pressure drop of the trickling biofilter was also measured during experiments.Increasing liquid flow rate and gas flow rate resulted in the decrease of purification efficiency of trickling biofilter. The highest purification efficiency of trickling biofilter was found at the circulation liquid pH of 7. The porosity of the packing material at the inlet of gas was higher than that at the outlet of gas in biofilter after continuous operation in 50 days. The decrease in the porosity of packing material caused a great increase in the pressure drop of the biofilter.     

Measurements and modeling of heat generation in a trickling biofilter for biodegradation of a low concentration volatile organic compound (VOC)

The experimental and theoretical heat generation behavior of a trickling biofilter treating toluene is discussed. The experimental results show that the temperature of the packed bed has a significant effect on the purification performance of the trickling biofilter and that an optimal operation temperature exists between 30 and 40 °C. During the gas–liquid co-current flow, the temperature in the packed bed gradually rises along the direction of the gas and liquid flow due to the exothermic biodegradation of toluene. The temperature rise between the inlet and outlet of the trickling biofilter increases with an increase in the gas flow rate and inlet toluene concentration. In addition, a larger liquid flow rate leads to a smaller temperature rise. The heat generation process occurring in the trickling biofilter is modeled by representing the packed bed as an equivalent set of parallel capillary tubes covered by the biofilm. The temperature profile in the packed bed during the liquid–gas co-current flow is analyzed by simultaneously solving the problem of gas–liquid two-phase flow and heat and mass transfer through the liquid film and biofilm. It is shown that the model agrees well with the experimental data, predicting the variations of the temperature rise between the inlet and outlet of trickling biofilter with the increasing gas and liquid flow rates.     

Removal of Xylene from Waste Gases using Biotrickling Filters

Two identical laboratory‐scale biotrickling filters, filled with different ceramic materials, were operated in order to investigate the removal of xylene from a waste gas stream. The biotrickling filter columns were seeded with pure bacteria identified as Bacillus firmus, which can utilize xylene as the sole carbon and energy source. The purification performance of the biotrickling filters was examined for xylene inlet concentrations C_g ≤ 3000 mg/m³ at different gas flow rates of 0.2 m³/h, 0.6 m³/h, and 1 m³/h, which correspond to gas empty bed residence times (EBRTs) of 84.8 s, 28.3 s, and 17.0 s, respectively. Both biofilters displayed a removal efficiency of no less than 95 % with the inlet xylene less than 3000 mg/m³ at the EBRTs of 84.8 and 28.3 s. When EBRT decreased to 17.0 s, the biofilter filled with ceramic particle type 2 had a better performance. The flow rate of trickling liquid has little effect on the removal efficiencies of the two filters. In the case of uneven distribution of trickling liquid in the packing materials, the performance of the biofilter can be improved by increasing the nitrogen nutrient supplement. Biomass quantity decreases as the depth of packing material increases in both biofilters, but the biofilter filled with ceramic particle type 1 had more alive bacteria per unit mass of packing material than the other.     

微量有机化合物和一氧化碳催化燃烧反应器数学模拟

建立了废气中含有甲苯、一氧化碳、丙烯混合物催化燃烧反应器的数学模型.多组分混合物催化燃烧反应动力学模型采用吸附解离态的氧与吸附态的反应物反应的机理推导得到了反应速率方程.模拟计算了废气处理量、废气中各组分的浓度、床层入口温度对转化率的影响.     

Biofiltration of xylene emissions: bioreactor response to variations in the pollutant inlet concentration and gas flow rate

In order to remove xylene vapors from an air stream, an upflow laboratory scale biofilter was operated for a period of 2 months. The experimental study consisted of two different phases: in the first phase, the biofilter was operated at various gas flow rates and the xylene inlet concentration was maintained at 1.39 g m⁻³. In the second phase, various inlet concentrations of the contaminant were tested at a constant gas flow rate of 0.4 m³ h⁻¹ corresponding to an empty bed residence time of 150 s. The biofilter response to steep and abrupt variations in the xylene inlet concentration and gas flow rate was examined. The results obtained revealed that the removal efficiency of the biofilter regained its high values (above 96%) in less than 24 h following the change to low concentrations and gas flow rate. Temperature measurements showed that the biofilter temperature strongly depends on the intensity of the microbial activity in the filter bed. The experimental mass ratio of carbon dioxide produced to the xylene removed was equal to 2.72 indicating that the contaminant was eliminated exclusively by aerobic biodegradation. These findings suggest that a follow up of the amount of carbon dioxide produced in the filter bed can be very helpful in monitoring the performance of the biofilter. For relatively small inlet loads of xylene, the contributions of the different sections of the biofilter to the removal efficiency of the contaminant and the carbon dioxide production were unevenly balanced but became more uniformly distributed for relatively high inlet loads.     

生物法净化低浓度甲苯废气研究

研究了不同气体入口浓度、填料层高度、操作方式下生物膜填料塔对低浓度甲苯废气的净化性能,并对净化过程控制步骤进行了探索。     

有机废气的生化处理实验研究

研究表明，采用国内现有微生物菌种挂膜接种的生物膜料塔净经低浓度有机废气是可行的，初步实验研究结果显示，增加人口气体甲苯浓度和气体流量，同时减小循环液喷淋量，可使甲苯的生化去除量增大，每升体积的生物膜填料对甲苯的生化去除量最大可达１５７．１３ｍｇ／ｈ。由实验结果推断，生物膜填料塔对废气中甲苯的净化去除过程属于传质控制过程，甲苯在生物膜内的降解为一级生化反应过程。     

生物膜填料塔净化低浓度有机废气的动力学模型研究

为了开展生物化学法净化处理低浓度有机废气的理论及应用研究，针对生物膜填料塔建立了甲苯生化降解反应的动力学模型，对比验证的结果表明，模拟计算值与实验值之间有很好的相关性（相关系数Ｒ＞０．９６），故可利用这一模式由已知的操作参数对生物膜填料塔的净化效果进行预测。