Effect of Carbon/Nitrogen Ratio, Temperature, and Inoculum Source on Hydrogen Production from Dark Codigestion of Fruit Peels and Sewage Sludge

Valorization of fruit wastes for circular bioeconomy: Current advances, challenges, and opportunities

The demands for fruits and processed products have significantly increased following the surging human population growth and rising health awareness. However, an enormous amount of fruit waste is generated during their production life-cycle due to the inedible portion and perishable nature, which become a considerable burden to the environment. Embracing the concept of "circular economy", these fruit wastes represent sustainable and renewable resources and can be integrated into biorefinery platforms for valorization into a wide range of high-value products. To fully realize the potential of fruit waste in circular bioeconomy and provide insights on future commercial-scale applications, this review presented the recycling and utilization of fruit wastes in various applications, particularly focusing on pollutant bioremediation, renewable energy and biofuel production, biosynthesis of bioactive compounds and low-cost microbial growth media. Furthermore, the challenges of efficient valorization of fruit wastes were discussed and future prospects were proposed.

Food Waste: A Promising Source of Sustainable Biohydrogen Fuel

Annually, approximately 1.3 billion tons of food is lost worldwide, accounting for one-third of annual food production. Therefore, turning food waste into energy is of enormous environmental significance because of its sustainable nature. Nutrients and organic acids present in food waste can be used to produce (bio)products such as biohydrogen through biological processes. However, our understanding of the production of biohydrogen from food waste through photofermentation and dark fermentation is still restricted. This comprehensive study aims to review the potential of food waste for biohydrogen production using microbial mediators, including a brief overview of process parameters that affect the (bio)hydrogen production pathway.