Ammonia conversion characteristics in a closed recirculating aquaculture system
Nitrification and denitrification were commonly used in the recirculating aquaculture system (RAS) to decrease the ammonia and nitrate concentration. The variation characteristics of nitrogenous compounds and microbiology in a closed RAS were studied with gradually increasing ammonia-nitrogen (NH4 +-N) concentration. The NH4 +-N was completely converted into nitrite nitrogen (NO2 --N) in 46 days, but the NO2 --N raised slowly since the ammonia-oxidizing rate was faster than the nitrite-oxidizing rate. The NO2 --N descended when the NH4 +-N concentration in the aquarium was stable for several days. Time for the NO2 --N decline gradually became longer if we continued increasing the NH4 +-N concentration. The nitrogen loss (residual total nitrogen/total additive nitrogen) was about 20-40％ during the experiment. The numbers of two kinds of bacteria showed that the increase of nitrification activity of the system was mainly attributed to the exit of numerous ammonium-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB). Data indicated that nitrification and aerobic denitrification can be both perfectly achieved in aerobic and low COD (Chemical Oxygen Demand) conditions. Marine nitrifiers from this approach led to the development of bacterial amendments that can be used as startup cultures for new operations or damaged filters, and potentially enhance nitrification in established filters.
Nitrogenous compound Bacteria Nitrification Aerobic denitrification Recirculating Aquaculture Systems (RAS)
Guang-yu Wang Ji-xian Yang Fang Ma Lei Chen Wei-Guo Li Jingbo Guo
State Key Lab of Urban Water Resource and Environment Harbin Institutes of Technology (HIT) Harbin,P State Key Lab of Urban Water Resource and Environment Harbin Institutes of Technology (HIT) Harbin,P The Marine College,Harbin Institutes of Technology (HIT) (Weihai),P.R.China
国际会议
北京
英文
1-4
2009-06-11（万方平台首次上网日期，不代表论文的发表时间）