Microalgae: a multifaceted catalyst for sustainable solutions in renewable energy, food security, and environmental management

Abstract

This review comprehensively examines the various applications of microalgae, focusing on their significant potential in producing biodiesel and hydrogen, serving as sustainable food sources, and their efficacy in treating both municipal and food-related wastewater. While previous studies have mainly focused on specific applications of microalgae, such as biofuel production or wastewater treatment, this review covers these applications comprehensively. It examines the potential for microalgae to be applied in various industrial sectors such as energy, food security, and environmental management. By bridging these different application areas, this review differs from previous studies in providing an integrated and multifaceted view of the industrial applications of microalgae. Since it is essential to increase the productivity of the process to utilize microalgae for various industrial applications, research trends in different microalgae cultivation processes, including the culture system (e.g., open ponds, closed ponds) or environmental conditions (e.g., pH, temperature, light intensity) to improve the productivity of biomass and valuable substances was firstly analyzed. In addition, microalgae cultivation technologies that can maximize the biomass and valuable substances productivity while limiting the potential for contamination that can occur when utilizing these systems have been described to maximize CO₂ reduction. In conclusion, this review has provided a detailed analysis of current research findings and technological innovations, highlighting the important role of microalgae in addressing global challenges related to energy, food supply, and waste management. It has also provided valuable insights into future research directions and potential commercial applications in several bio-related industries, and illustrated how important continued exploration and development in this area is to realize the full potential of microalgae.

Keywords: Biofuel production; Biohydrogen production; Bioreactors; Culture system; Environmental sustainability; Microalgae; Sustainable food sources; Wastewater treatment.

Fig. 1

Diverse applications of microalgae as sustainable and environmentally friendly resources. Microalgae are emerging as a sustainable solution for biodiesel, wastewater treatment, future food sources, food waste treatment and hydrogen production. Biodiesel production from microalgae helps to reduce CO₂ emissions and provide a sustainable source of energy. In wastewater treatment, microalgae have the ability to remove pollutants and reduce CO₂. Microalgae is a promising alternative for future food source as it could potentially use as a high-protein food and a variety of nutrients. In food waste treatment, microalgae can efficiently use organic wastes like banana peels and convert it into valuable products. Microalgae can also be used to absorb solar energy and produce hydrogen in an environmentally friendly way. Thus, microalgae can be applied in a variety of industries for sustainable and environmentally friendly techniques

Fig. 2

Parameters necessary to maximize the biomass and valuable substances productivity in the microalgae outdoor culture systems. There are many ways to produce biomass effectively. For example, there are ways to utilize culture systems suited to each environment, such as open ponds, raceway ponds, and closed systems, or to control contaminants that cause significant losses in biomass and valuable substances productivity. In addition, regulating environmental conditions like pH, temperature, and light intensity can maximize biomass and valuable substances productivities. These factors can also increase by improving the reactors used in each culture system