Unit Processes In RAS SystemsAmmonia-, Nitrite-Nitrogen Concerns; Biofiltration

摘要

Since un-ionized ammonia-nitrogen and nitrite-nitrogen are toxic to most finfish, controlling their concentrations in culture tanks is a primary objective in the design of recirculating aquaculture systems. Biological filtration is widely used to control these compounds. Trickling filters provide reliable nitrification, aeration and some carbon dioxide removal in one unit. Fluid-ized bed filters use inexpensive media to offer high nitrification capacity in a compact size. Moving bed reactors are compact and have low energy requirements and relatively stable nitrification.