Recovery of bioproducts and water reuse from food industry effluents

Subproject 2 of the coordinated project PHOTOBIO+, led by the University of Almería (UAL), focuses on the cultivation and valorization of microalgae biomass using food industry effluents, in line with circular economy principles and sustainable resource management. This subproject explores two distinct pathways depending on the type of effluent used: clean (non-contaminated) effluents and wastewater (contaminated effluents), each contributing to different end-products and applications.

Microalgae cultivated in clean effluents will serve as a source of high-value biomolecules. Following cultivation under optimized conditions, the biomass will be fractionated using advanced separation techniques, such as ceramic membranes with different pore sizes, to obtain three key fractions: proteins, carbohydrates, and lipids. The proteins will be evaluated for their potential application in animal feed or agricultural products, paying special attention to their nutritional properties, such as digestibility and amino acid profile. Carbohydrates will serve as a source of biopolymers for the development of biodegradable bioplastics, offering an eco-friendly alternative to conventional plastics. Lipids will also be analyzed, focusing on their suitability for use in animal feed. This fractionation process ensures an integral valorization of the biomass, contributing to a zero-waste system while generating high-value products for various markets.

On the other hand, microalgae cultivated in contaminated effluents will absorb nutrients and pollutants from waste streams, allowing for efficient effluent treatment. The resulting biomass will be processed to obtain biostimulants intended for agricultural applications. These biostimulants will be tested in field trials to evaluate their efficacy in improving crop yields, particularly under stress conditions such as drought and salinity, which are expected to become more frequent due to climate change.

Furthermore, Subproject 2 will assess the feasibility of reusing the reclaimed water during the microalgae cultivation process. This water will undergo detailed characterization, including the evaluation of emerging contaminants and compliance with new European Union directives, to ensure its safety and suitability for agricultural irrigation. The impact of this reclaimed water on crop growth and soil health will also be studied to validate its reuse potential within a circular system.

UAL’s Subproject 2 is expected to demonstrate the potential of innovative processes to transform food industry effluents into valuable bioproducts at a demonstration scale. This work not only addresses critical environmental challenges, such as wastewater management and resource recovery, but also contributes to the development of sustainable agricultural practices. The results of this subproject aim to improve resource use efficiency, reduce environmental impact, and create new opportunities for bio-based industries, supporting the overall goals of the PHOTOBIO+ coordinated project.