| Summary: | Hydrogen sulfide (H<sub>2</sub>S) is a toxic and corrosive component that commonly occurs in biogas. In this study, H<sub>2</sub>S removal from swine-waste biogas using sulfur-oxidizing <i>Paracoccus versutus</i> CM1 immobilized in porous glass (PG) and polyurethane foam (PUF) biofilters was investigated. Bacterial compositions in the biofilters were also determined using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The biofilters were first tested on a laboratory scale under three space velocities (SV): 20, 30, and 40 h<sup>−1</sup>. Within 24 h, at an SV of 20 h<sup>−1</sup>, PG and PUF biofilters immobilized with <i>P. versutus</i> CM1 removed 99.5% and 99.7% of H<sub>2</sub>S, respectively, corresponding to the elimination capacities (EC) of 83.5 and 86.2 gm<sup>−3</sup> h<sup>−1</sup>. On a pilot scale, with the horizontal PG-<i>P. versutus</i> CM1 biofilter operated at an SV of 30 h<sup>−1</sup>, a removal efficiency of 99.7% and a maximum EC of 113.7 gm<sup>−3</sup> h<sup>−1</sup> were achieved. No reduction in methane content in the outlet biogas was observed under these conditions. The PCR-DGGE analysis revealed that <i>Paracoccus, Acidithiobacillus</i>, and <i>Thiomonas</i> were the predominant bacterial genera in the biofilters, which might play important roles in H<sub>2</sub>S removal. This PG–<i>P. versutus</i> CM1 biofiltration system is highly efficient for H2S removal from swine-waste biogas.
|
|---|