以氯苯为目标污染物,选择CuO/MnO2作为耦合系统中的催化剂,采用介质阻挡放电(Dielectric Barrier Discharge,DBD)技术协同催化作为生物系统的预处理技术,开展废气净化的研究.实验结果发现,耦合生物滴滤塔(Biotrickling Filter,BTF)和单一生物滴滤塔系统分别在13 d和15 d内完成挂膜,氯苯的去除率分别达到100%和97%.稳定运行期,停留时间(EBRT)为90 s时,单一BTF在处理低进气浓度氯苯废气时,去除效果与耦合系统相当;进气浓度较大时,耦合系统的处理效果要明显优于单一BTF.EBRT缩短至45 s时,无论氯苯进气浓度高或低,耦合系统的处理效果均优于单一BTF.单一BTF的最大去除负荷(Eliminatory Capacity,ECmax)为41 g·m^-3·h^-1,在同样实验条件下,耦合系统未达到最大去除负荷,而耦合系统和单一BTF对氯苯的矿化率分别为95%和86%.DBD协同催化能有效改善BTF对于高进气负荷氯苯废气的处理,预处理工艺能强化BTF对氯苯废气的彻底净化.通过对各功能单元对氯苯去除的贡献分析,发现DBD协同CuO/MnO2工艺主要负责转化氯苯,BTF下段填料主要负责预处理工艺产生的中间产物的矿化,BTF上段填料主要负责剩余氯苯的去除及其矿化.
Using chlorobenzene as the target pollutant and CuO/MnO2 as the catalyst in the coupling system,this study adopted Dielectric Barrier Discharge( DBD) synergistic catalysis as a pretreatment technique of the biological system. Experiment results showed that coupled biotricking filter( BTF) and single BTF achieved biofilm formation in 13 d and 15 d with chlorobenzene elimination rate of 100% and 97%,respectively. During the stabilization period when EBRT was 90 s,coupled and single BTFs showed similar elimination rate with a low chlorobenzene concentration. In comparison,when the chlorobenzene concentration was high,the elimination rate of coupled BTF was significantly higher than that of single BTF. The maximum eliminatory capacity( ECmax) of single BTF was 41 g·m^-3·h^-1,while ECmaxwas not achieved for coupled BTF. The maximum mineralization rate of the single and combined BTFs was 95% and 86%,respectively. DBD synergistic analysis could effectively improve the elimination of chlorobenzene with high concentration,and the pretreatment process could promote the pollutants degradation in BTF. By analyzing contributions of different functional units in the elimination system,it was found that the DBD-catalysis process was mainly responsible for conversion of chlorobenzene,the upper BTF packing was mainly responsible for the treatment of residual chlorobenzene and its mineralization,and the BTF low layer was mainly responsible for degrading intermediates produced in the pretreatment process.