exemplified by the nitrifying bacteria which colonize biofilter elements in
biofilter units is central to recirculating aquaculture systems.
however uncontrolled growth of biofilm on biofilter carriers and other surfaces, including walls and
pipes. The presence, potential implication and consequences of this biofilm is
not known. Excessive biofilm growth may lead to impaired nitrification, anoxic zones which in saltwater
systems increases the risks of unwanted HS2 release. Further issues caused by
biofilm growth can affect geosmine levels, water and tank hydraulic, impair
trickling filter efficacy, potentially hide pathogens and led to increased disinfection demand.
investigate biofilm formation and associated bacterial activity and dynamics, a
number of experimentally controlled studies are needed.
The studies can include
test and monitoring of biofilm under different conditions, i.e. as a result of
increase dissolved organic matter content, in relation to maintenance and
cleaning procedures or when exposed to water borne chemical. Studies looking
into flow-patterns and/or use of tracers will also shed new light on the
emerging issue relevant for the development and understanding of RAS operation.
Related biofilm investigations can also be made on biofilter elements from controlled experimental RAS and commercial fish farms. The methodology can include gravimetric determination of biofilm formation and include modification of a recent assys to assess microbial activity "Assessment of microbial activity in water based on hydrogen peroxide decomposition rates. 2019. Aquacultural Engineering, 85, 9-14."