Engineered Biomaterials for Reducing Phosphorus and Nitrogen Levels from Downstream Water of Aquaculture Facilities

Abstract

The United States (U.S.) has a nearly USD 17 billion seafood trade deficit annually. However, the U.S. aquaculture industry faces strict micronutrient (e.g., phosphorus and nitrogen) level mandates that negatively impact fish production, especially for the state of Idaho, which produces 70–75% of the nation’s rainbow trout. This study investigates the sustainability benefits of producing engineered biomaterials from lignocellulosic-based feedstocks near collection sites via portable biorefineries for use by fish farms to reduce eutrophication (oversupply of micronutrients) impacts. In this study, sustainability assessments are performed on a case study in southern Idaho, the largest U.S. commercial producer of rainbow trout. The results show that 20 and 60 min of water treatment, using small particle size biomaterial from lodgepole pine, has the highest total phosphorus removal rate, at 150–180 g of phosphorus per 1 metric ton of engineered biomaterials. The results of techno-economic and environmental impacts studies indicate that pinewood-based biomaterials production cost ranges from USD 213 USD 242 per ton and reduces the eutrophication potential by 5–17 kg PO4eq/ton. Additionally, the environmental impact results show that the total greenhouse gas emission for biomaterial production is 47–54 kg CO2eq/ton; however, the used biomaterials after water treatment can be sold for around USD 850 per ton as nutrient-rich soil conditioners. This study concluded that engineered biomaterials from lignocellulosic-based feedstocks could be a sustainable solution to the challenge that aquaculture faces, particularly capturing micronutrients from eutrophic water and reusing them as fertilizers.

Controlling Eutrophication of Aquaculture Production Water Using Biochar: Correlation of Molecular Composition with Adsorption Characteristics as Revealed by FT-ICR Mass Spectrometry

“…Nitrate, nitrite, and ammonium adsorption efficiency of biochar increased with longer residence times for IB. Contrary to our previous results of short water treatment (residence) time experiments (5-60 min) for the static water treatment system, there is a visible correlation between the adsorption of phosphorus and nitrogen compounds seen in IB samples [22]. Key parameters (e.g., residence time and biochar pH) had relatively strong associations with adsorbed compounds.…”

“…The main objective of this study is to explore the remediation of aquaculture-generated water by a novel water treatment approach based on engineered biochars from woody feedstocks that have the potential to be recycled and reused as nutrient-rich fertilizers. Our earlier studies show that pinewood can effectively adsorb micronutrients (P and N) from water [22]. Thus, this study focuses on biochars from different pinewoods (e.g., lodgepole or mixed ponderosa pine and spruce trees).…”

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

“…Emerging solutions such as phytoremediation and adsorbents/filtration offer promising approaches to address phosphorus pollution. These methods are based on the use of aquatic plants and mechanical and biological filters to remove excess phosphorus from the water [128][129][130][131][132][133]. Phytoremediation in river aquaculture can also be based on the use of floating aquatic plants, such as water hyacinth (Eichhornia crassipes) and duckweed (Lemna spp.…”

“…Additionally, biomaterials derived from lodgepole pine have been utilized to reduce aquaculture waste and mitigate micronutrient-induced eutrophication. Treating rainbow trout effluents with these biomaterials for up to 60 min resulted in the removal of 150 to 180 g of phosphorus per metric ton, providing a method for eutrophication reduction in aquaculture [130]. The economic costs associated with these strategies can be a determinant of their potential applications in aquaculture.…”