Study on treatment of coking wastewater using process of photosynthetic bacteria enhanced two-stage of fluidized beds

Key words: 
• coking wastewater /
• photosynthetic bacteria /
• intergrowth /
• short-cut nitrification and denitrification

Abstract: The process of anaerobic acidification with fluidized beds was adopted to treat coking wastewater. The intergrowth of photosynthetic bacteria and hydrolyticacidogenic bacteria was in the first reactor,and the intergrowth of photosynthetic bacteria and nitrite bacteria was in the second reactor. After the abundant low-molecule weight organic acid decreased by photosynthetic bacteria and macromolecule organic matter secondhydrolyzed in the first reactor, the second treatment was completed in the second reactor. With some conditions as temperature、pH、DO、concentration of substrate etc, short-cut nitrification was achieved in the second reactor so that the carbon source was used effectively. The results from the steady run after two months were analysed, and the concentrations of effluent COD and NH3-N were 105～135 mg/L and 14～20 mg/L respectively, with the removal rates of 90.3%～92.5% and 92%～95%. The removal rate of TN was the range of 83%～86%, the removal rates of phenol、cyanide and BOD5 were more than 95%.