Recovery of Phenolic Compounds from Orange Peel Waste by Conventional and Assisted Extraction Techniques Using Sustainable Solvents.

Background: The valorization of orange peel waste (OPW) through the extraction of bioactive compounds is a clear example of the circular economy. OPW contains many value-added compounds, among which bioactive phenolic compounds (flavonoids and phenolic acids) could be extracted and used for industrial applications, such as pharmaceuticals or cosmetics.

Methods: In this work, the extraction of phenolic compounds from orange peel was carried out by conventional (orbital shaker) and assisted (ultrasound and microwave) extraction techniques using deionized water, 80% (v/v) ethanol in water, and ethyl acetate as solvents.

Removal of NO at low concentration from air in urban built environments by activated miscanthus biochar.

This work presents an innovative and sustainable approach to remove NO emissions from urban ambient air in confined areas (underground parking areas or tunnels) using low-cost activated carbons obtained from Miscanthus biochar (MSP700) by physical activation (with CO or steam) at temperatures ranging from 800 to 900 °C. The NO removal capacity of the activated biochars was evaluated under different conditions (temperature, humidity and oxygen concentration) and compared against a commercial activated carbon. This last material showed a clear dependence on oxygen concentration and temperature, exhibiting a maximum capacity of 72.

Enhanced Recovery of Natural Antioxidants from Grape Waste Using Natural Eutectic Solvents-Based Microwave-Assisted Extraction.

The evaluation of sustainable solvents as alternatives to more harmful conventional solvents combined with intensification techniques to recover phenolic compounds from agri-food waste is in the spotlight. The wine industry generates large amounts of waste as a consequence of grape processing operations, which can be revalued by solvent extraction of valuable antioxidants for food and fine chemical applications. Therefore, the present study focuses on the use of natural eutectic solvents (NAESs) with benign environmental, health, and safety profiles, for valorization of grape waste in the context of a circular economy.