The nitrification process for nitrogen removal in biofloc system aquaculture

Abstract

Aquaculture is an economic activity that faces the unavoidable problem of water quality detriment, which is mainly generated by the improper management of production ponds, including inadequate water circulation and aeration, accumulation of undigested food residues, excretion of metabolic by‐products by the cultivated organisms and other. In addition, the increase in suspended organic matter together with the presence and generation of nitrogen compounds can severely affect the physiology of the animal, leading to significant losses in production. Ammonia (NH3), nitrite (NO2) and nitrate (NO3) are toxic in different scales and environmental conditions; therefore, reducing their concentrations in the culture units has paramount relevance. In this regard, bioflocs are an efficient alternative to transform nitrogen compounds into a non‐toxic form, taking advantage of the capabilities of the microbial communities conforming them. Also, nitrogen can be harnessed and incorporated as organic nitrogen, making the biofloc a source of useful natural food for the cultivated organism. The substantial reduction in the rate of water exchange favoured by the biofloc technology (BFT) is a beneficial advantage for both the production systems and the environment, diminishing the risk of introducing pathogens into the pond in parallel with the improvement in the water quality of effluents. Ammonia oxidation is an advantage adding value to the BFT systems and is discussed in this review.

Growth performance, digestive enzyme activity, non‐specific immune response and stress enzyme status in early stages of grey mullet reared in a biofloc system

“…During the 60 days of experimental trial, the average biofloc volume in the BFT was in a desirable range, that is 25–50 ml L −1 for finfish culture (Hargreaves, 2013). Biofloc helps to preserve the water quality suitably even in intensive and hyper‐intensive culture with low or no water exchange (Crab et al, 2012; Robles‐Porchas et al, 2020). Hence the results indicate that biofloc technology can be used for maintaining appropriate culture conditions for the rearing of grey mullet in zero or low water exchange biofloc system.…”

Longitudinal variations in the gastrointestinal microbiome of the white shrimp, Litopenaeus vannamei

“…Consequently, the ideal condition requires the rapid oxidation of ammonia/ammonium to nitrite and, then, to nitrate. Such processes are carried out in aerobic environments by ammonia-oxidizing bacteria and nitrite-oxidizing bacteria ( Robles-Porchas et al, 2020 ). On the whole, metabolic predicted functions in the digestive tract fractions are necessary for adequate host development.…”

Supplemental carbon sources applied in biofloc technology aquaculture systems: types, effects and future research

“…NO À 2 accumulation is toxic to aquaculture organisms and can compromise their growth and welfare (Bussel et al 2012;Furtado et al 2015). The nitrification process occurs in most BFT systems (Nootong et al 2011;Luo et al 2020;Robles-Porchas et al 2020). Therefore, monitoring and controlling NO À 2 levels have become important considerations in BFT practice.…”

“…Robles-Porchas et al (2020) have extensively reviewed the important role of nitrification in BFT systems for the removal of nitrogen compounds from the culture water. The end product of the nitrification process in any given system is nitrate nitrogen (Ward et al 2011;Robles-Porchas et al 2020). Nitrate accumulation in BFT systems is an indication of ongoing nitrification and signifies the completion of this process.…”

“…2011; Robles‐Porchas et al . 2020). Nitrate accumulation in BFT systems is an indication of ongoing nitrification and signifies the completion of this process.…”