Review of waste phosphorus from aquaculture: Source, removal and recovery

Abstract

The contribution of phosphorus to water body eutrophication is a global environmental problem, and rapid increases in aquaculture are considered a significant source of phosphorus discharged into the environment. The current review focuses on the source of aquaculture waste phosphorus and measures to decrease phosphorus release into the environment. Because diets are a significant source of phosphorus in fed aquaculture systems, improving the utilization efficiency of dietary phosphorus can reduce the amount of waste phosphorus at the source. A wide range of removal and recovery technologies has been identified, including adsorption, crystallization, enhanced biological phosphorus removal (EBPR), denitrifying phosphorus removal, heterotrophic nitrification aerobic denitrification (HAND) and photosynthetic organism removal. Recovery technologies were also reviewed, particularly sludge phosphorus from recirculating aquaculture systems. A new method using bacteria to immobilize waste nitrogen and phosphorus into bioflocs has been proposed as a better solution. However, most of these technologies have only been implemented at the lab scale to pilot scale. Further studies are necessary to determine the working conditions and removal capacities of related technologies on a commercial scale.Moreover, phosphorus removal methods must be selected based on a consideration of recyclability.

Addressing Phosphorus Waste in Open Flow Freshwater Fish Farms: Challenges and Solutions

“…As a result, there are a variety of emerging or refined management strategies that can be used to reduce phosphorus pollution from aquaculture, including developing existing and new approaches, such as substituting fish meal with plant proteins and reducing the amount of phosphorus in the feed [69], optimizing feeding regimes to reduce FCR or daily feed intake, using water treatment technologies to remove phosphorus from wastewater, and developing sustainable aquaculture practices that reduce the environmental impact of fish farming [124][125][126][127]. However, the feasibility and effectiveness of these strategies depend on various factors, such as the type of aquaculture system, the type of fish being farmed, and the local environmental conditions.…”

Optimizing Nutrient Utilization, Hydraulic Loading Rate, and Feed Conversion Ratios through Freshwater IMTA-Aquaponic and Hydroponic Systems: An Environmentally Sustainable Concept

“…Incorporating extractive species (for example, invertebrates and/or seaweeds) into existing monoculture systems, such as integrated multi-trophic aquaculture (IMTA), has the potential to improve farm pro tability, animal welfare, and economic bene ts 13 . As a production system, IMTA-aquaponics may provide new insights into water management, increased sh biomass, improved feed conversion ratios, potential wastewater reduction, and recognition of external in uences affecting monoculture production, as well as strategies to avoid them associated with diversi ed aquaponics crop production [14][15][16] .…”

Circularity Assessment in Aquaculture: The Case of Integrated Multi-Trophic Aquaculture (IMTA) Systems

“…In addition to the definition, the range of examples is also very extensive for aquaculture, and no previous studies are available that provide the state of the art of the real and current implementation of the circular economy in the sector [10]. The concept of circular aquaculture can be addressed in many ways [11], but generally, circularity in aquaculture includes the adoption of practices regarding waste management [12][13][14], the recycling of nutrients [15][16][17][18], or the incorporation of novel ingredients in feeds derived from the bio-economy [19,20].…”

“…Within IMTA systems, uneaten feed and nutrient losses can be recaptured by other organisms and converted into valuable nutrients for harvestable seafood and crops [23]. Fish excrete nitrogenous and phosphorus waste, the dissolved component of which can be utilized by cultivated seaweed species as a nutrient source for growth, thus reducing nutrient levels in the water and preventing eutrophication [13]. Additionally, filter-feeding organisms such as mussels and oysters can help in the removal of excess nutrients as particulate matter by efficiently filtering water [24].…”