Chou Ming-Shean, Wu Feh-Loong
a Institute of Environmental Engineering, National Sun Yat-Sen University , Kaoshiung , Taiwan , Republic of China.
J Air Waste Manag Assoc. 1999 Apr;49(4):386-398. doi: 10.1080/10473289.1999.10463817.
This study utilized a biotrickling filter with blast-furnace slag packings (sizes = 20-40 mm; specific surface area = 120 m/m) to treat toluene in an air stream. Also studied were the effects of volumetric loading (L), nutrient addition, and superficial gas velocity (U) or gas retention time on toluene elimination capacity. Experimental results indicate that, for a test period of 121 days, with no excess biomass removal, toluene removal efficiencies of over 90% were obtained with U < 80 m/hr and L < 30 g/m.hr. For a test period of 49 days, with U < 80 m/hr and L increased from 1.2 to 81 g/m.hr, the absence of nutrient supplementation did not limit the toluene elimination capacity. Nutrients stored in the biofilm could adequately support the microbial activity for the toluene elimination. According to data regression, a simplified mass-transfer model is proposed, which correlates the contaminant concentration with the packing height or gas empty bed retention time. As verified, the model proposed herein can be applied to cases involving low influent contaminant concentrations or loadings to the extent that none or only a trace amount of the contaminant can be found in the recirculation liquid. Although small media with larger specific surface areas can achieve a better mass transfer, the problems of frequent backwashing and relatively greater gas resistance in using this type of media probably outweigh the advantages, particularly for full-scale systems that would not be watched as closely as laboratory test systems.
本研究采用装有高炉矿渣填料（尺寸 = 20 - 40 毫米；比表面积 = 120 平方米/立方米）的生物滴滤池处理气流中的甲苯。还研究了体积负荷（L）、营养物添加以及表观气速（U）或气体停留时间对甲苯去除能力的影响。实验结果表明，在 121 天的测试期内，在不进行多余生物质去除的情况下，当 U < 80 米/小时且 L < 30 克/立方米·小时时，甲苯去除效率超过 90%。在 49 天的测试期内，当 U < 80 米/小时且 L 从 1.2 增加到 81 克/立方米·小时时，不添加营养物并不限制甲苯去除能力。生物膜中储存的营养物能够充分支持微生物去除甲苯的活性。根据数据回归，提出了一个简化的传质模型，该模型将污染物浓度与填料高度或气体空床停留时间关联起来。经验证，本文提出的模型可应用于进水污染物浓度或负荷较低的情况，即在循环液中未发现或仅发现微量污染物的程度。尽管具有较大比表面积的小尺寸填料可以实现更好的传质，但使用这类填料时频繁反冲洗的问题以及相对较大的气体阻力可能超过其优势，特别是对于不会像实验室测试系统那样密切监测的全尺寸系统。
