一种缓释复合生物填料性能评价

Performance evaluation of a slow-release composite media for biofiltration

采用浸渍法,获得一种具有缓释功能的废气生物过滤填料,并以甲苯模拟废气,进行了该填料各项性能评价.填料理化特性分析表明,缓释填料的空隙率为88%,堆密度为164.3kgm-3,压缩强度为22.4kPa,比表面积为9.9×104m2m-3,pH为7.9;其营养结构与泥质填料相近,有机质、有机碳、总氮、总磷含量分别为72.2%、54.7%、1.63%、0.07%;缓释填料能长期在潮湿环境中保持良好的黏结强度,并具有营养缓释功能.BF试验正常运行阶段,填料层平均干、湿生物量分别为11.6kgm-3和287.4kgm-3,阻力系数为1.3×104～8.9×104m-1;当进气流量为88m3h-1、处理负荷小于128gm-3h-1时,甲苯去除率维持在82%以上.系统闲置停运12d后需性能恢复时间为2d.

In this study,a novel composite media with a function of slow release was prepared by means of impregnation,and its performances in a pilot-scale biofiltration of toluene waste gas were evaluated.The void fraction of the novel media was 0.88,with a bulk density of 164 kg m-3,a compressive strength of 22.4 kPa,a specific surface area of 9.9×104 m2 m-3,and pH of 7.9.The contents of organic matter,organic carbon,nitrogen and phosphor in composite media were 72.2%,54.7%,1.63% and 0.07%,respectively,with a similar nutritional composition to argillaceous media.The media could maintain good cohesive strength in moist environment for long term,and its nutrients could release slowly.During normal operation of the biofiltration experiment,the average weights of biomass immobilized on media were 11.6 kg m-3（dry wt） and 287.4 kg m-3（wet wt）,and the resistance coefficient of media bed was 1.3×104～8.9×104 m-1,respectively.The toluene removal efficiency remained over 82% when the inlet loading was lower than 128 g m-3 h-1 at a gas flow rate of 88 m3 h-1.Besides,only 2 days were needed for the recovery of the biofiltration performance after a 12-day shutdown.