April 2007
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5 Reads
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2 Citations
Two autotrophic rod sulfur-oxidizing strains (zw1 and zw2) were isolated from Pharmaceutical wastewater containing hydrogen sulfide gas, and were streaked and purified by repeated transfer to fresh solid medium on the plate. Shape, physiological and biochemical characteristic of chemolithoautroph zw1 and zw2 was checked, and removal capacity of hydrogen sulfide gas from hydrolyzation tank in wastewater treatment plant was investigated by the inoculated biofilter with zw1 and zw2. The results suggested that the optimal temperature of zwl (aerobic bacilli, short rod and Gram-positive) was between 22°C and 32°C and the optimal pH was between 5.0 and 7.0. And the optimal temperature of zw2 (facultatively-aerobic bacilli, long rod and Gram-negative) was between 22°C and 25°C and the optimal pH was between 4.0 and 6.5. Furthermore, the inoculated biofilter with zw1 and zw2 had stronger ability to resist shock of high inlet loading. Removal efficiency of hydrogen sulfide was close to 100% when the maximum volumetric loading achieved 192 g/(m·h). Metabolism products of zwl and zw2 were mainly composed of SO42- and the biofilter was not blocked during the experiment of more than three months. Therefore, the biofilter need not carry out a back washing frequently and it can be operated steadily for long-term. It is a potential industrialization method that can be fulfilled easily.