TY - JOUR
T1 - Removal of hydrogen sulfide by sulfate-resistant Acidithiobacillus thiooxidans AZ11
AU - Lee, Eun Young
AU - Lee, Nae Yoon
AU - Cho, Kyung Suk
AU - Ryu, Hee Wook
N1 - Funding Information:
This work was financially supported by the Korea Science and Engineering Foundation through the Advanced Environmental Biotechnology Research Center at Pohang University of Science and Technology (R11-2003-006).
PY - 2006/4
Y1 - 2006/4
N2 - Toxic H2S gas is an important industrial pollutant that is applied to biofiltration. Here, we examined the effects of factors such as inlet concentration and space velocity on the removal efficiency of a bacterial strain capable of tolerating high sulfate concentrations and low pH conditions. We examined three strains of Acidithiobacillus thiooxidans known to have sulfur-oxidizing activity, and identified strain AZ11 as having the highest tolerance for sulfate. A. thiooxidans AZ11 could grow at pH 0.2 in the presence of 74 g l-1 sulfate, the final oxidation product of elemental sulfur, in the culture broth. Under these conditions, the specific sulfur oxidation rate was 2.9 g-S g-DCW (dry cell weight)-1 d-1. The maximum specific sulfur oxidation rate of A. thiooxidans AZ11 was 21.2 g-S g-DCW-1 d-1, which was observed in the presence of 4.2 g-SO42- l-1 and pH 1.5, in the culture medium. To test the effects of various factors on biofiltration by this strain, A. thiooxidans AZ11 was inoculated into a porous ceramic biofilter. First, a maximum inlet loading of 670 g-S m-3 h-1 was applied with a constant space velocity (SV) of 200 h-1 (residence time, 18 s) and the inlet concentration of H2S was experimentally increased from 200 ppmv to 2200 ppmv. Under these conditions, less than 0.1 ppmv H2S was detected at the biofilter outlet. When the inlet H2S was maintained at a constant concentration of 200 ppmv and the SV was increased from 200 h-1 to 400 h-1 (residence time, 9 s), an H2S removal of 99.9% was obtained. However, H2S removal efficiencies decreased to 98% and 94% when the SV was set to 500 h-1 (residence time, 7.2 s) and 600 h-1 (residence time, 6 s), respectively. The critical elimination capacity guaranteeing 96% removal of the inlet H2S was determined to be 160 g-S m-3 h-1 at a space velocity of 600 h-1. Collectively, these findings show for the first time that a sulfur oxidizing bacterium has a high sulfate tolerance and a high sulfur oxidizing activity below pH 1.
AB - Toxic H2S gas is an important industrial pollutant that is applied to biofiltration. Here, we examined the effects of factors such as inlet concentration and space velocity on the removal efficiency of a bacterial strain capable of tolerating high sulfate concentrations and low pH conditions. We examined three strains of Acidithiobacillus thiooxidans known to have sulfur-oxidizing activity, and identified strain AZ11 as having the highest tolerance for sulfate. A. thiooxidans AZ11 could grow at pH 0.2 in the presence of 74 g l-1 sulfate, the final oxidation product of elemental sulfur, in the culture broth. Under these conditions, the specific sulfur oxidation rate was 2.9 g-S g-DCW (dry cell weight)-1 d-1. The maximum specific sulfur oxidation rate of A. thiooxidans AZ11 was 21.2 g-S g-DCW-1 d-1, which was observed in the presence of 4.2 g-SO42- l-1 and pH 1.5, in the culture medium. To test the effects of various factors on biofiltration by this strain, A. thiooxidans AZ11 was inoculated into a porous ceramic biofilter. First, a maximum inlet loading of 670 g-S m-3 h-1 was applied with a constant space velocity (SV) of 200 h-1 (residence time, 18 s) and the inlet concentration of H2S was experimentally increased from 200 ppmv to 2200 ppmv. Under these conditions, less than 0.1 ppmv H2S was detected at the biofilter outlet. When the inlet H2S was maintained at a constant concentration of 200 ppmv and the SV was increased from 200 h-1 to 400 h-1 (residence time, 9 s), an H2S removal of 99.9% was obtained. However, H2S removal efficiencies decreased to 98% and 94% when the SV was set to 500 h-1 (residence time, 7.2 s) and 600 h-1 (residence time, 6 s), respectively. The critical elimination capacity guaranteeing 96% removal of the inlet H2S was determined to be 160 g-S m-3 h-1 at a space velocity of 600 h-1. Collectively, these findings show for the first time that a sulfur oxidizing bacterium has a high sulfate tolerance and a high sulfur oxidizing activity below pH 1.
KW - Acidithiobacillus thiooxidans
KW - biofilter
KW - hydrogen sulfide
KW - sulfate tolerance
UR - http://www.scopus.com/inward/record.url?scp=33745766928&partnerID=8YFLogxK
U2 - 10.1263/jbb.101.309
DO - 10.1263/jbb.101.309
M3 - Article
C2 - 16716938
AN - SCOPUS:33745766928
SN - 1389-1723
VL - 101
SP - 309
EP - 314
JO - Journal of Bioscience and Bioengineering
JF - Journal of Bioscience and Bioengineering
IS - 4
ER -