Performance of a full-scale anoxic-oxic activated sludge treatment plant（4.0×10-5 m-3/day for the first-stage project） was followed during a year.The plant performed well for the removal of carbon,nitrogen and ...Performance of a full-scale anoxic-oxic activated sludge treatment plant（4.0×10-5 m-3/day for the first-stage project） was followed during a year.The plant performed well for the removal of carbon,nitrogen and phosphorus in the process of treating domestic wastewater within a temperature range of 10.8℃ to 30.5℃.Mass balance calculations indicated that COD utilization mainly occurred in the anoxic phase,accounting for 88.2% of total COD removal.Ammonia nitrogen removal occurred 13.71% in the anoxic zones and 78.77% in the aerobic zones.The contribution of anoxic zones to total nitrogen（TN） removal was 57.41%.Results indicated that nitrogen elimination in the oxic tanks was mainly contributed by simultaneous nitrification and denitrification（SND）.The reduction of phosphorus mainly took place in the oxic zones,51.45% of the total removal.Denitrifying phosphorus removal was achieved biologically by 11.29%.Practical experience proved that adaptability to gradually changing temperature of the microbial populations was important to maintain the plant overall stability.Sudden changes in temperature did not cause paralysis of the system just lower removal efficiency,which could be explained by functional redundancy of microorganisms that may compensate the adverse effects of temperature changes to a certain degree.Anoxic-oxic process without internal recycling has great potential to treat low strength wastewater（i.e.,TN 〈 35 mg/L） as well as reducing operation costs.展开更多
In this study, landfill leachate with and without pre-treatment was co-treated with municipal wastewater at different mixing ratios. The leachate pre-treatment was achieved by air stripping to removal ammonia. The obj...In this study, landfill leachate with and without pre-treatment was co-treated with municipal wastewater at different mixing ratios. The leachate pre-treatment was achieved by air stripping to removal ammonia. The objective of this study was to investigate the effect of landfill leachate on nutrient removal of the wastewater treatment process. It was demonstrated that when landfill leachate was co-treated with municipal wastewater, the high ammonia concentration in the leachate did not have a negative impact on the nitrification. The system was able to adapt to the environment and was able to improve nitrification capacity. The readily biodegradable portion of chemical oxygen demand（COD）in the leachate was utilized by the system to improve phosphorus and nitrate removal.However, this portion was small and majority of the COD ended up in the effluent thereby decreased the quality of the effluent. The study showed that the 2.5% mixing ratio of leachate with wastewater improved the overall biological nutrient removal process of the system without compromising the COD removal efficiency.展开更多
基金supported by the National High Technology Research and Development Program (863 Program) of China (No. 2012AA063302)the Jiangsu Water Protection Project (No. 2015005)
文摘Performance of a full-scale anoxic-oxic activated sludge treatment plant（4.0×10-5 m-3/day for the first-stage project） was followed during a year.The plant performed well for the removal of carbon,nitrogen and phosphorus in the process of treating domestic wastewater within a temperature range of 10.8℃ to 30.5℃.Mass balance calculations indicated that COD utilization mainly occurred in the anoxic phase,accounting for 88.2% of total COD removal.Ammonia nitrogen removal occurred 13.71% in the anoxic zones and 78.77% in the aerobic zones.The contribution of anoxic zones to total nitrogen（TN） removal was 57.41%.Results indicated that nitrogen elimination in the oxic tanks was mainly contributed by simultaneous nitrification and denitrification（SND）.The reduction of phosphorus mainly took place in the oxic zones,51.45% of the total removal.Denitrifying phosphorus removal was achieved biologically by 11.29%.Practical experience proved that adaptability to gradually changing temperature of the microbial populations was important to maintain the plant overall stability.Sudden changes in temperature did not cause paralysis of the system just lower removal efficiency,which could be explained by functional redundancy of microorganisms that may compensate the adverse effects of temperature changes to a certain degree.Anoxic-oxic process without internal recycling has great potential to treat low strength wastewater（i.e.,TN 〈 35 mg/L） as well as reducing operation costs.
基金funded by the Natural Sciences and Engineering Research Council of Canada (NSERC) under the Engage Grant (EGP 463799-2014) with collaboration with KGS Groups (Winnipeg, Canada)
文摘In this study, landfill leachate with and without pre-treatment was co-treated with municipal wastewater at different mixing ratios. The leachate pre-treatment was achieved by air stripping to removal ammonia. The objective of this study was to investigate the effect of landfill leachate on nutrient removal of the wastewater treatment process. It was demonstrated that when landfill leachate was co-treated with municipal wastewater, the high ammonia concentration in the leachate did not have a negative impact on the nitrification. The system was able to adapt to the environment and was able to improve nitrification capacity. The readily biodegradable portion of chemical oxygen demand（COD）in the leachate was utilized by the system to improve phosphorus and nitrate removal.However, this portion was small and majority of the COD ended up in the effluent thereby decreased the quality of the effluent. The study showed that the 2.5% mixing ratio of leachate with wastewater improved the overall biological nutrient removal process of the system without compromising the COD removal efficiency.
