Environmental Footprint of Inland Fisheries: Integrating LCA Analysis to Assess the Potential of Wastewater-Based Microalga Cultivation as a Promising Solution for Animal Feed Production

Abstract

This study evaluated the environmental impacts of producing 1 kg of biomass for animal feed grown in inland fisheries effluents as a culture medium using the ReCiPe method. Four scenarios with two downstream alternatives were modeled using the life cycle assessment method: Algal Life Feed (ALF), Algal Life Feed with Recycled nutrients (ALF+Rn), Pelletized Biomass (PB), and Pelletized Biomass with Recycled nutrients (PB+Rn). The findings reveal a substantial reduction in environmental impacts when wastewater is employed as a water source and nutrient reservoir. However, the eutrophication and toxicity-related categories reported the highest normalized impacts. ALF+Rn emerges as the most promising scenario due to its reduced energy consumption, highlighting the potential for further improvement through alternative energy sources in upstream and downstream processes. Therefore, liquid waste from fish production is a unique opportunity to implement strategies to reduce the emission of nutrients and pollutants by producing microalgae rich in various high-value-added metabolites.

Life Cycle Assessment of Exopolysaccharides and Phycocyanin Production with Arthrospira platensis

“…Pierre et al (2019) highlight the connection between microalgae biomass production and factors such as light intensity and aeration levels, underscoring a direct correlation with photosynthesis activity [37,[51][52][53][54]. Notably, the enhanced biomass production of diverse microalgae species, including Cyanospira capsulata, Porphyridium, and Synechococcus, as well as the researched cyanobacteria A. platensis, is particularly notable under conditions of high continuous light irradiance [25][26][27][28]. This becomes apparent in the study setups when simulated for a situation characterized by increased solar exposure.…”

“…For the midpoint category, we consider marine eutrophication, climate change aspects, and cumulative energy demand associated with non-renewable resources. Some of these classifications have been used in other microalgae biomass studies [25,26] . Meanwhile, within the endpoint category, our focus extends to water consumption and its impact on aquatic ecosystems and human health.…”