Isolation of autohydrogenotrophic bacteria and its performance for the removal of nitrate and sulfate from wastewater

• Main Authors: Wang, Po-Wei, 王柏崴
• Other Authors: Huang, Chih-Pin
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/jr63zj

碩士 === 國立交通大學 === 環境工程系所 === 105 === Chemical and pharmaceutical wastewaters, and landfills leachate often contain high loading of nitrate and sulfate. The high concentration of nitrate and sulfate will affect our health and cause environmental damage if we can’t process them properly. Autohydrogenotrophic bacteria, possessing a removal capacity for nitrate and sulfate, have low carbon demand and addicted hydrogen to be electron donors. In addition, its performance for removal of nitrate and sulfate is very well in short period of time. Although there were many studies on the denitrification and sulfate reduction of autohydrogenotrophic bacteria, the effect of different nitrogen and sulfate ratio on denitrification and sulfate reduction and the autohydrogenotrophic bacteria community are still unclear. This study aims to isolate of autohydrogenotrophic bacteria, as well as to investigate the effect of nitrogen and sulfate ratio on the nitrate and sulfate removal efficiency. The results showed that Methyloversatilis universalis, Pseudoxanthomonas japonensis, and Flavobacterium psychrophilum were isolated from our lab-scale autohydrogenotrophic bacteria anaerobic bioreactor. For isolated strains, the nitrate removal rate of Flavobacterium psychrophilum was 87.8% and the sulfate removal rate of Pseudoxanthomonas japonensis was 65.6% in 72 hours. For mixed culture, the nitrate and sulfate removal rate were found at 93% and 60% respectively. The effect of sulfate reduction of mixed culture on different nitrogen and sulfate ratio would be inhibition when nitrate was residual in the aqueous solution. Overall, autohydrogenotrophic bacteria have ability for both denitrification and sulfate reduction, of which performance would be affected by the amount of nitrate in the aqueous solution.