The distillery wastewater of Guangdong Jiujiang Distillery, which is characteristic of containing high organic matters and rich total nitrogen, was treated by a combination of methane fermentation and denitrification/...The distillery wastewater of Guangdong Jiujiang Distillery, which is characteristic of containing high organic matters and rich total nitrogen, was treated by a combination of methane fermentation and denitrification/nitrification processes. 80% of COD in the raw wastewater was removed by methane fermentation at the COD volumetric loading rate of 20 kg COD/（m^3·d） using the expanded granule sludge bed （EGSB） process. However, almost all the organic nitrogen in the raw wastewater was converted into ammonia by ammonification there. Ammonia and volatile fatty acids （VFA） remaining in the anaerobically treated wastewater were simultaneously removed utilizing VFA as an electron donor by denitrification occurring in the other EGSB reactor and nitrification using PEG-immobilized nitrifying bacteria with recirculation process. An aerobic biological contact oxidization reactor was designed between denitrification/nitrification reactor for further COD removal. With the above treatment system, 18000-28000 mg/L of COD in raw wastewater was reduced to less than 100 mg/L. Also, ammonia in the effluent of the system was not detected and the system had a high removal rate for 900-1200 mg/L of TN in the raw wastewater, only leaving 400 mg/L of nitrate nitrogen.展开更多
Three strains of aerobic denitrifiers,named as AT3,AT6 and AT7,were isolated from concentric-circles reactor with diversion wall possessing simultaneous nitrification and denitrification (SND) effect of 69%. The three...Three strains of aerobic denitrifiers,named as AT3,AT6 and AT7,were isolated from concentric-circles reactor with diversion wall possessing simultaneous nitrification and denitrification (SND) effect of 69%. The three strains are all gram-positive and rod-shaped,and their colonial colors are pale yellow,milk white and pink,respectively. Combined with 16SrDNA sequence homology comparison and biochemical tests,AT3 and AT7 were identified to belong to Rhodococcus,and AT6 to Gordonia. These bacterial strains could grow well in the medium with potassium nitrate as nitrogen source and sodium citrate as carbon source. Based on the enhanced nitrogen removal experiments of selected bacteria mixture for activated sludge,the inoculum amount of 5% was supposed to be proper. The mixed biomass suspension of selected strains with PVA immobilization was put into the concentric-circles reactor in order to study the characteristics of enhanced nitrogen removal after amplifying cultivation with inoculated amount of 5%. The experimental results show that the average removal efficiencies of ammonia nitrogen (NH3-N) and total nitrogen (TN) in the reactor enhanced with aerobic denitrifying bacteria using PVA are 92.18% and 79.14% respectively,increasing by 5.29% and 7.83% respectively compared with removal effects of control group without strains enhancement.展开更多
文摘The distillery wastewater of Guangdong Jiujiang Distillery, which is characteristic of containing high organic matters and rich total nitrogen, was treated by a combination of methane fermentation and denitrification/nitrification processes. 80% of COD in the raw wastewater was removed by methane fermentation at the COD volumetric loading rate of 20 kg COD/（m^3·d） using the expanded granule sludge bed （EGSB） process. However, almost all the organic nitrogen in the raw wastewater was converted into ammonia by ammonification there. Ammonia and volatile fatty acids （VFA） remaining in the anaerobically treated wastewater were simultaneously removed utilizing VFA as an electron donor by denitrification occurring in the other EGSB reactor and nitrification using PEG-immobilized nitrifying bacteria with recirculation process. An aerobic biological contact oxidization reactor was designed between denitrification/nitrification reactor for further COD removal. With the above treatment system, 18000-28000 mg/L of COD in raw wastewater was reduced to less than 100 mg/L. Also, ammonia in the effluent of the system was not detected and the system had a high removal rate for 900-1200 mg/L of TN in the raw wastewater, only leaving 400 mg/L of nitrate nitrogen.
基金Science and Technology Cooperation Project (2007DFA90660) supported by the International Cooperation Program of Ministry of Science and TechnologyProject(CSTC,2008BB7305) supported by the Natural Science Funds of ChongqingProject(CSTS,2006AA7003) supported by the Major Scientific and Technical Program
文摘Three strains of aerobic denitrifiers,named as AT3,AT6 and AT7,were isolated from concentric-circles reactor with diversion wall possessing simultaneous nitrification and denitrification (SND) effect of 69%. The three strains are all gram-positive and rod-shaped,and their colonial colors are pale yellow,milk white and pink,respectively. Combined with 16SrDNA sequence homology comparison and biochemical tests,AT3 and AT7 were identified to belong to Rhodococcus,and AT6 to Gordonia. These bacterial strains could grow well in the medium with potassium nitrate as nitrogen source and sodium citrate as carbon source. Based on the enhanced nitrogen removal experiments of selected bacteria mixture for activated sludge,the inoculum amount of 5% was supposed to be proper. The mixed biomass suspension of selected strains with PVA immobilization was put into the concentric-circles reactor in order to study the characteristics of enhanced nitrogen removal after amplifying cultivation with inoculated amount of 5%. The experimental results show that the average removal efficiencies of ammonia nitrogen (NH3-N) and total nitrogen (TN) in the reactor enhanced with aerobic denitrifying bacteria using PVA are 92.18% and 79.14% respectively,increasing by 5.29% and 7.83% respectively compared with removal effects of control group without strains enhancement.
