板式生物滴滤塔高效净化硫化氢废气的研究

采用营养液分层喷淋、pH分别在线控制(pH 2.5、 4.5、 6.5)的板式生物滴滤塔(plate type-biotrickling filter, PTBTF)净化H₂S废气,考察PTBTF于挂膜启动及稳定运行阶段对H₂S的降解性能.结果表明,PTBTF系统在14 d内即完成挂膜,对浓度为188.6mg·m^-3的H₂S去除率达到100%;在进口浓度100～1000mg·m^-3、空床停留时间(EBRT)28～4 s的条件下,H₂S的去除率可达到99%以上;当H₂S去除率≥90%时, PTBTF系统的最大去除负荷随EBRT(3.3～6 s)的增加而增大,EBRT 6 s的最大去除负荷达到1019.0g·(m³·h)^-1;上、中、下3层填料对H₂S的去除负荷随进口H₂S负荷的波动呈显著变化;通过荧光染色观察填料上的细胞数,发现在挂膜阶段微生物数量增长明显,第125 d上层、中层和下层填料上的菌落数(以干填料计)分别达到了1.29×10⁷、 5.47×10⁸和1.07×10⁹个·g^-1;采用扫描电镜观察填料表面的生物膜,可见上填料层和下填料层的优势菌分别为杆菌和丝状菌;利用变性梯度凝胶电泳初步揭示了系统运行过程中生物群落的演替规律;通过对产物的分析,确定该PTBTF系统降解H₂S后主要产生SO^2-₄和单质硫.

Removal of Hydrogen Sulfide by Plate Type-Biotrickling Filter

A plate type biotrickling filters (plate type-biotrickling filter, PTBTF) in which three layers are separately sprayed by nutrient solution of pH 2.5, 4.5 and 6.5, relatively, was designed for H2S removal at the start-up and steady states. The biofilm formation of PTBTF was completed within 14 d, and the removal efficiency of 100% was achieved at the inlet H2S concentration of 188.6 mg x m(-3). Afterwards, H2S removal efficiency remained above 99% with the inlet concentration between 100 mg x m(-3) and 1 000 mg x m(-3) and empty bed residence time (EBRT) between 28 s and 4 s. When removal efficiency was 90%, the maximum elimination capacity of PTBTF increased with EBRT (3.3-6 s), e. g. 1 019.0 g x (m3 x h)(-1) for EBRT 6 s. The elimination capacity of the upper, middle and lower layer varied with the inlet H2S loading. It was found that the microorganisms onto the packing carriers in upper, middle and lower layers increased significantly at the start-up state, and reached 1.29 x 10(7), 5.47 x 10(8), and 1.07 x 10(9) cells x g(-1), respectively, in 125 d by the means of fluorescence staining. The bacilliform and filamentous microorganisms were the dominants in the upper and lower layer, respectively, observed by scanning electron microscopy. The biological community analysis by denaturing gradient gel electrophoresis was also conducted in this study. The main products of SO4(2-) and sulfur were determined for H2S degradation.