分期布液生物滴滤床净化H_2S废气性能研究

Performance of Cross Flow Trickling Filter for H_2 S Gas Treatment

采用分期布液式生物滴滤床净化H2S废气,以实验室驯化的复合微生物菌群挂膜于滴滤床,考察了挂膜启动及不同负荷运行对H2S的降解性能.结果表明,生物滴滤床在进气浓度110～230 mg.m-3,停留时间30 s的条件下,H2S去除率可达到99%,3 d内即完成挂膜.进气负荷对于滴滤床降解性能和微生物种群都有影响.低进气负荷时,净化效率>90%,降解作用主要发生于反应器的前段,占85%以上.前段各种类微生物数量上均多于后段,尤其是硫化氢降解菌;进气负荷较高时,前段微生物数量没有明显变化;后段去除负荷增加明显,由0.04 g.h-1增长到0.67 g.h-1.微生物数量由4.5×107个.g-1增长到5.17×108个.g-1.采用扫描电镜观察填料表面,稳定运行时优势菌主要为短杆菌,高负荷状态下,填料表面被大量的代谢产物覆盖.对运行产物分析发现,大部分H2S被氧化为S,只有小部分彻底氧化分解为SO24-.

A grading cross bio-trickling filter was designed for H2 S removal.Mixed microorganisms domesticated from the former experiment were immobilized to start up the trickling filter.Removal performances during starting up period and different loadings were investigated.Results showed that the immobilization of the trickling filter was completed within 3 d.The removal efficiency was higher than 99% when the inlet concentration was in the range of 110 mg·m^-3 to 230 mg·m^-3（EBRT 30 s）.At low inlet loadings,the front part of the trickling filter played a major role in H2 S degradation,accounting for about 85%.Microbial diversity and population of the front part were superior to the tail one.At higher loadings,microbial diversity and population of the tail part increased significantly,from 4.5×107 cells·g^-1 to 5.17×108 cells·g^-1,and the elimination capacity was also improved,from 0.04 g·h^-1 to 0.67 g·h^-1.Rod-shaped bacteria were the dominant microorganisms on the surface of ceramics in the steady state as observed by SEM.The surfaces of ceramics were covered by a lot of microbial metabolites at high loadings.Analysis of the metabolites indicated that the majority of H2 S was oxidized to sulfur and only a small portion was converted to sulfate.