Feed dosage and ammonium control device based on C/N ratio for a zero-discharge system

Abstract

In intensive aquaculture, one solution to water use efficiency is to add carbohydrates (CH) to the system, in order to develop a bacteria population able to process the inorganic nitrogen produced by the un-eaten food and fish excretion. This method has been tested in the past few decades, proving to be a very efficient solution for water treatment in situ. Fish are poikilothermic vertebrates and their feeding rate varies according to temperature. As a result, food and CH dosage must be carefully calculated in conditions where the water temperature cannot be controlled. This paper presents the development, implementation and testing of a low cost system of feed dosage and ammonium control device (FDACD) based on C/N ratio, through the CH addition, that considers temperature to dose feed in an aquaculture system, controlling the total ammonium nitrogen (TAN) flux to maintain the tank with "zero discharge", heightening the profitability and contributing to solve the aquaculture sustainability problem.