Influence of temperature, ammonia load and hydraulic loading on the performance of nitrifying trickling filters for recirculating aquaculture systems

Abstract

[EN] In recirculating aquaculture systems, performance of nitrifying biofilters for total ammonia nitrogen (TAN) removal from the culture water and thus minimizing eutrophication depends on numerous elements of design. In this article the combined effect of three of these process parameters (temperature, hydraulic loading and TAN load) is evaluated. Ammonia removal rates (N-TAN divided by biofiltration area and day) were measured for every combination of five different temperatures, three different hydraulic loadings and three different ammonia loads. Every one of the process parameters were influential on nitrification rates and the lowest process parameters values corresponded with significantly lower N-TAN removal rates. A significantly higher mean N-TAN removal rate (0.241 gN-TAN removed m¿2 day-1) was found for the combination of the highest water temperature (27¿°C), the highest hydraulic loading (11 m3¿m¿2¿h-1) and the highest TAN load (9 gTAN m-3 day-1), suggesting a positive synergy of the three process parameters on the achievement of greater biofilter performances.