Control of Ammonia and Hydrogen Sulfide Emissions by the Fluidized-bed Biological Reactor Packed for Immobilized Ammonia-oxidizing and Sulfur-oxidizing Bacteria
| Autor: | Chia-Ho Liu, 劉嘉和 |
|---|---|
| Rok vydání: | 1999 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 87 Heterotrophic Pseudomonas putida and Heterotrophic Arthrobacter oxydans were immobilized with Ca-alginate to form bioactive beads, and then were packed in the fluidized-bed biofilter system. The removal efficiency and capacity for H2S and NH3 were evaluated. The effect of operating parameters, included pH value, phosphate concentration, and inlet gas concentration, on the removal efficiency and capacity was evaluated. In the hydrogen sulfide removal experiment, the system exhibited high H2S removal efficiency(in excess of 95 %)at H2S concentrations from 10 ppm to 110 ppm and flow rates below 36 l/h. The maximum removal rate(Vm)and the saturation constant(Ks)were determined 7.010-8 g-S/cell/day and 76.2 ppm, respectively. Hydrogen sulfide was mainly converted to elemental sulfur, which can be reused. Thus, immobilized P. putida biofilter appears to be a promising method to treat H2S emissions. In ammonia removal, 90% of NH3 removal efficiency was reached at initial concentrations of NH3 less than 100 ppm and flow rates below 27 l/h. Ammonia was mainly converted to nitrite-N. The maximum removal rate(Vm)and the saturation constant(Ks)were calculated as 1.8810-6 g-N/cell/day and 30.5 ppm, respectively. Compared to fixed-bed biofilter, the fluidized-bed biofilter has smaller Ks value. Heterotrophic P. putida and A. oxydans were also co-immobilized to remove H2S and NH3 from waste gases simultaneously. The results showed that the H2S removal efficiency of the biofilter was significantly affected by high concentrations of NH3(60 ppm). On the other hand, NH3 removal efficiency of the biofilter was not affected by H2S concentrations(5-60 ppm). The amount of bioaerosol generated was less than that of the traditional biofilter. Therefore, employing immobilized cell technology can cause less environmental impact and higher operational stability. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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