Process modelling of an intensive aquaculture system

The application of process modelling concepts to an intensive recirculating aquaculture system is described. Advanced Continuous Simulation Language (ACSL) for describing the unsteady behaviour of complex continuous flow system is applied to a simplified recycle fish rearing system comprising a rearing tank and a treatment unit. Use of the technique was validated by comparison with analytical solutions of the unsteady state mass balance equations for the transfer and removal of ammonia. The language is successfully implemented to study the dynamic behaviour of ammonia concentration and in response to changes imposed upon the system. The effects of choice of design and operating parameters upon the response of the system are illustrated. Parameters studied include vessel size, lag, flowrate, recycle ratio and mixing regime.