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Difference between revisions of "Biofilters"
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==Use in aquaculture== | ==Use in aquaculture== | ||
The use of biofilters are commonly used on closed aquaculture systems, such as recirculating aquaculture systems (RAS). Many designs are used, with different benefits and drawbacks, however the function is the same: reducing water exchanges by converting ammonia to nitrate. Ammonia (NH4+ and NH3) originates from the brachial excretion from the gills of aquatic animals and from the decomposition of organic matter. As ammonia-N is highly toxic, this is converted to a less toxic form of nitrite (by <i>Nitrosomonas</i> sp.) and then to an even less toxic form of nitrate (by <i>Nitrobacter</i> sp.). This "nitrification" process requires oxygen (aerobic conditions), without which the biofilter can crash. Furthermore, as this nitrification cycle produces H+, the pH can decrease which necessitates the use of buffers such as lime. | The use of biofilters are commonly used on closed aquaculture systems, such as recirculating aquaculture systems (RAS). Many designs are used, with different benefits and drawbacks, however the function is the same: reducing water exchanges by converting ammonia to nitrate. Ammonia (NH4+ and NH3) originates from the brachial excretion from the gills of aquatic animals and from the decomposition of organic matter. As ammonia-N is highly toxic, this is converted to a less toxic form of nitrite (by <i>Nitrosomonas</i> sp.) and then to an even less toxic form of nitrate (by <i>Nitrobacter</i> sp.). This "nitrification" process requires oxygen (aerobic conditions), without which the biofilter can crash. Furthermore, as this nitrification cycle produces H+, the pH can decrease which necessitates the use of buffers such as lime. | ||