Different Approaches for Treating Aquaculture Wastewater and Its Reuse

In recent times, civilization has been facing significant challenges due to the swift growth of population resulting in the depletion of natural resources and environmental deterioration. The pressing issue of food scarcity for the expanding global population has become more critical due to unforeseen shifts in climate conditions. Addressing this, the aquaculture industry emerges as one of the pivotal players in mitigating worldwide food shortages. By 2028, statistics indicate an elevation from an average of 52% (considering the data of 2016–2018) to 58% in the contribution of aquaculture-derived fish for human consumption. However, water quality has been compromised in traditional aquaculture systems which ultimately have exhibited detrimental effects to aquatic resources through water pollution. Minimizing water discharge by recycling the water used for aquaculture production would help in achieving sustainability in the aquaculture system. This study compares various wastewater treatment technologies, analyzing their role in enhancing sustainability. Among various technologies, immobilized systems with careful selection of microbes within aquaculture units have demonstrated the highest effectiveness in managing wastewater volumes within 14 h by maintaining its water quality in terms of reducing ammonia (83.96%) and nitrite (89.22%) toxicity which are the major pollutants of aquaculture production system. Recirculating aquaculture systems (RAS) with constructed wetland systems exhibit notable efficiency in treating wastewater containing nitrogenous compounds, with higher removal rates of ammonia (86–98%) and nitrite (99%). An alternative technology known as the integrated multi-trophic aquaculture (IMTA) strategy has enhanced the production of shellfish by 20% and increased overall profit by 230% as compared to isolated finfish and shellfish monocultures by maintaining the water quality of its aquaculture units. However, larger land requirements and the careful selection of organisms are the major challenges for these systems. The development of more efficient treatment strategies and an integrated, complete approach to wastewater treatment are crucial in ensuring sustainable aquaculture. These approaches are essential in maintaining equilibrium within the water-food-energy relationship, contributing significantly to sustainable systems.