生物滴滤塔对疏水性VOCs气体的去除及其生物膜特性研究

利用正己烷降解菌Pseudomonas mendocina NX-1和二氯甲烷（DCM）降解菌Methylobacterium rhodesianum H13强化生物滴滤塔（BTF）同时净化不同疏水性的正己烷和DCM混合废气，研究了挂膜启动阶段及稳定运行阶段BTF对污染物的去除性能与限制因素及生物膜相的特性变化.结果表明，在正己烷和DCM浓度均为100 mg·m^-3，停留时间（EBRT）为60 s的条件下，运行25 d即可完成BTF的启动，正己烷和DCM的去除率分别可达到65%和100%.系统稳定运行时，正己烷和DCM的最大去除负荷分别为16.1 g·m^-3·h^-1和92.0 g·m^-3·h^-1.正己烷和DCM的去除过程分别受到传质限制与反应限制影响.BTF稳定运行后，塔内生物膜胞外聚合物（EPS）中蛋白质（PN）含量逐渐增加至启动时的2.7倍，蛋白质与多糖的比值（PN/PS）从0.28增加至0.96.生物膜表面相对疏水性从21%增加至66%，Zeta电位从-12.7 mV降低至-9.2 mV.压降的模拟结果与实验数据良好拟合（R²>0.96）.

Characteristics of biofilm using biotrickling filter to remove hydrophobic VOCs gas

The intensification of a biotrickling filter (BTF) removes mixed waste gases of n-hexane and dichloromethane (DCM) with different hydrophobicity levels by using Pseudomonas mendocina NX-1 and Methylobacterium rhodesianum H13. We studied the performance of pollutant removal, its limited step, and the change in biofilm phase characteristics in the start-up and stable operation of BTF. Results show that BTF start-up can be completed after 25 days of operation with 100 mg·m^-3 of n-hexane and DCM concentrations and 60 s of empty bed residence time; 65% and 100% of n-hexane and DCM, respectively, can be removed. The maximum load removal of n-hexane and DCM can reach 16.1 g·m^-3·h^-1 and 92.0 g·m^-3·h^-1, respectively, when BTF is operating stably. The removal of n-hexane and DCM is affected by mass transfer and reaction restrictions, respectively. After the stable operation of BTF, the extracellular polymeric substances (EPS) and protein (PN) contents in BTF gradually increase to 2.7 times compared with those in the start-up, PN/PS(polysaccharide) increases from 0.28 to 0.96, the relative hydrophobicity of the biofilm increases from 21% to 66%, and the zeta potential is reduced from -12.7 mV to -9.2 mV. The simulated results of pressure drop agree well with the experimental data of BTF (R²>0.96).