Triboelectric Nanogenerator from Used Surgical Face Mask and Waste Mylar Materials Aiding the Circular Economy.

Apart from claiming the lives of more than 3.2 million people, the COVID-19 pandemic is worsening the global plastic pollution every day, mainly with the overflux of single-use polypropylene (PP) face masks. In this scenario, as an innovative solution to mitigate plastic pollution as well as to meet the rising electrical energy demand, we are introducing an all-flexible and facile waste material-based triboelectric nanogenerator (WM-TENG), aiding toward the circular economy. The WM-TENG operating in contact separation mode is fabricated using the PP from a used face mask in combination with recovered Mylar sheets from solid wastes as triboelectric contact layers and a flexible supporting structure. After detailed investigation and trials to study the effect of various disinfection mechanisms of PP materials on the energy output of WM-TENG, UV-C radiation is selected for disinfecting the used masks owing to the retention of electrical energy output. Under a tapping force of 3 N, the WM-TENG having an active area of 6 cm2 delivers an open-circuit voltage of 200 V and a short-circuit current density of 0.29 mA/m2, respectively. The WM-TENG also delivered a maximum power density of 71.16 mW/m2 under 108 Ω load. Additionally, the WM-TENG is demonstrated for powering electronic gadgets such as a calculator, digital thermometer, and LCD clock. This flexible and low-cost nanogenerator without any complex fabrication steps is a sustainable solution for the alarming plastic pollution as well as the rising energy demands.

The Potential of Selected Agri-Food Loss and Waste to Contribute to a Circular Economy: Applications in the Food, Cosmetic and Pharmaceutical Industries.

The food sector includes several large industries such as canned food, pasta, flour, frozen products, and beverages. Those industries transform agricultural raw materials into added-value products. The fruit and vegetable industry is the largest and fastest-growing segment of the world agricultural production market, which commercialize various products such as juices, jams, and dehydrated products, followed by the cereal industry products such as chocolate, beer, and vegetable oils are produced. Similarly, the root and tuber industry produces flours and starches essential for the daily diet due to their high carbohydrate content. However, the processing of these foods generates a large amount of waste several times improperly disposed of in landfills. Due to the increase in the world's population, the indiscriminate use of natural resources generates waste and food supply limitations due to the scarcity of resources, increasing hunger worldwide. The circular economy offers various tools for raising awareness for the recovery of waste, one of the best alternatives to mitigate the excessive consumption of raw materials and reduce waste. The loss and waste of food as a raw material offers bioactive compounds, enzymes, and nutrients that add value to the food cosmetic and pharmaceutical industries. This paper systematically reviewed literature with different food loss and waste by-products as animal feed, cosmetic, and pharmaceutical products that strongly contribute to the paradigm shift to a circular economy. Additionally, this review compiles studies related to the integral recovery of by-products from the processing of fruits, vegetables, tubers, cereals, and legumes from the food industry, with the potential in SARS-CoV-2 disease and bacterial diseases treatment.