Towards Shaping Integrated Circular Economy Approaches in Animal Breeding Supply Chains by Mainstreaming Microalgae Utilization

Abstract This paper presents a comprehensive literature review and analysis of sustainable biomass exploitation strategies, focusing on agro-waste residues and animal excreta. The research explores potential microalgal cultivation and utilization as a promising, low-energy alternative biomass source. While many production pathways are technologically feasible, their commercial viability under current market conditions is limited. The study aims to highlight sustainable water and biomass treatment methods and identify potential obstacles preventing agro-entrepreneurs from adopting integrated, viable algal-derived biomass exploitation. These strategies could contribute to greenhouse gas (GHG) mitigation, aligning with UN targets and EU legislation for a sustainable future. An extensive literature review was carried out over relative algae exploitation issues. A synthesis of techniques, innovative technologies and strategies were recorded so as to aim minimized mass and energy flux towards sustainable pathways. The proposed solutions, including soft water reclamation and novel biomass production, utilize well-established techniques and significant operational parameters for smart circular biomass flows. These approaches are interrelated to agribusiness and contribute to replenishing carbon and nitrogen surface pools, enabling better emission control and overall energy savings. The study emphasizes the potential for synergies in organized activities, such as co-locating cattle farms, greenhouses, and biogas plants to produce sustainable energy and create agri-biomass-based clusters with remarkable operational autonomy. The findings suggest that there are various areas of biomass exploitation which are quite promising in terms of embracing circular economy approaches and mitigating negative impacts in the agribusiness industry.