新型生物滴滤填料性能评价

Performance Evaluation of Three Novel Biotrickling Packings

填料是微生物附着生长、水分保持的支撑体,填料的性能直接关系到污染物的最终去除效果.研究开发了3种新型生物滴滤填料:纹翼多面球、改性毛刺球和空心多面柱.测试表明3种填料中,空心多面柱和纹翼多面球的结构特性参数均优于普通的生物滴滤填料,特别是比表面积,达到了200 m2·m-3左右.纹翼多面球的阻力系数ζ在挂膜前后几乎没有变化,而毛刺球的阻力系数ζ增长明显.生物滴滤塔(BTF)实验表明,采用空心多面柱的BTF挂膜启动的时间明显快于其他两种填料;稳定运行阶段实验结果表明,当甲苯和乙醇进口浓度分别为687.37 mg·m-3和651.17 mg·m-3时,采用纹翼多面球的BTF去除效果较好,对于两者的去除率分别达到了76.78%和99.23%.生物量测试表明,3种填料湿生物量也均高于普通的聚丙烯鲍尔环.纹翼多面球填料易实现生物膜的更新与剥落,稳定运行后期单位填料层压降维持在51.6 Pa·m-1,而毛刺球平均压降显著升高(193.3 Pa·m-1),出现了严重堵塞现象.

Packing is the support medium for microbial adhesion and water retention, and its characteristics are directly related to the removal of pollutants. In the present study, three novel biotrickling packings were developed： polyhedral sphere, burr sphere and polyhedral hollow column. The results showed that the structural characteristics of polyhedral sphere and polyhedral hollow column, with the specific surface area of 200 m2 .m-3, were better than those of traditional biotrickling packings. The resistance coefficient ξ of polyhedral sphere was almost identical before and after the biofilm formation. Under the same condition, ξof burr sphere increased much more. Investigations on the start-up time showed that the polyhedral hollow columns could contribute more to the quick biofilm formation. The performance of BTF which was packed with polyhedral sphere was better than the others. When the inlet concentrations of toluene and ethanol were 687.37 and 651.27 mg·m-3, the removal efficiencies achieved 76. 78% and 99.23%, respectively. Biomass measurements showed that the biomass adhering on these packings were more than that on the common polypropylene Bauer ring. Biofilm could be renewed and removed easily from the polyhedral sphere and the pressure drop could maintain at 52.6 Pa·m-1 at the later stable running phase. However, the pressure drop in the BTF which used burr sphere as the packings increased much more （193.3 Pa.m-1 ） , thus causing a clogging phenomenon.