Applications and studies on the biofilter in American industrialized recirculating aquaculture

The paper introduced some most popular types of biofilter in American industrialized recirculating aquaculture.They are microbead biofilter,bead filter series,fluidized sand biofilter and moving bed bio-reactor.Working theory,working performance,advantages and disadvantages,etc.are mainly described in the paper.Through comparison it is found that though there is a wide range of nitrification media can be chosen,the most important is to design a best way to make reaction.According to the backwashing type,the biofilter is divided as external-force and self-clean.The working status of self-clean biofilter is more stable and valuable for research and application.Biofiltration is the most important part in the recirculating aquaculture system.Anything such as filtration mode,backwashing strength,water quality will influence it's working performance.