Organic waste has the potential to produce methane gas as a substitute for petrol-based fuels, while reducing landfilling and possible environmental pollution. Generally, anaerobic digestion (AD) is used only in wastewater treatment plants as a tertiary stage of sewage sludge treatment, generating a fraction of the energy that such process plants require. In this study, four different wastes—food waste (FW), dairy industry waste (DIW), brewery waste (BW), and cardboard waste (CBW)—were tested for biogas production. The biochemical methane potential (BMP) of each sample was evaluated using an automatic methane potential system (AMPTS). Operating parameters such as pH, temperature, total solids, and volatile solids were measured. Experiments on the anaerobic digestion of the samples were monitored under mesophilic conditions (temperature 37 °C, retention time 30 days). Specific methane yields (SMYs), as well as the theoretical methane potential (BMPth), were used to calculate the biodegradability of the substrates, obtaining the highest biodegradability for BW at 95.1% and producing 462.3 ± 1.25 NmL CH₄/g volatile solids (VS), followed by FW at an inoculum-to-substrate ratio (ISR) of 2 at 84% generating 391.3 NmLCH₄/g VS. The BMP test of the dairy industry waste at an inoculum-to-substrate ratio of 1 was heavily inhibited by bacteria overloading of the easily degradable organic matter, obtaining a total methane production of 106.3 NmL CH₄/g VS and a biodegradability index of 24.8%. The kinetic modeling study demonstrated that the best-fitting model was the modified Gompertz model, presenting the highest coefficient of determination (R²) values, the lowest root means square error (RMSE) values for five of the substrates, and the best specific biogas yield estimation with a percentage difference ranging from 0.3 to 3.6%.

Organic solar cells (OSCs) are attractive photovoltaic technologies due to their mechanical flexibility, low weight, and compatibility with low-cost solution processing. Power conversion efficiencies above 20% have recently been achieved, largely through the development of non-fullerene acceptors and improved control of bulk-heterojunction morphology. However, insufficient operational lifetime continues to limit commercialization. Performance losses arise from interconnected photoinduced, thermal, morphological, interfacial, environmental, and mechanical processes that are accelerated under realistic operating conditions involving light, heat, oxygen, and moisture. This review examines the principal mechanisms responsible for these changes, with particular attention to photo-oxidation, thermally driven morphological evolution, and interfacial chemical reactions. Stability trends in donor:fullerene, donor:non-fullerene, and all-polymer systems are compared to establish relationships between material composition, microstructure, and device durability. Recent mitigation strategies are then assessed, including molecular design of more stable materials, processing routes that suppress unfavorable morphological evolution, interface and device engineering, and advanced encapsulation. The review is organized around a mechanism-to-mitigation framework that connects molecular, morphological, and interfacial degradation processes with their photovoltaic consequences and the corresponding stabilization strategies across fullerene, non-fullerene, and all-polymer systems. Recent advances demonstrate that appropriately stabilized NFA-based systems can retain ≥85–90% of their initial efficiency for hundreds to thousands of hours under thermal stress, while optimized interfaces have enabled operational lifetimes exceeding several thousand hours under accelerated aging. Remaining challenges include standardized stability protocols, reliable lifetime prediction, and scalable architectures that retain performance under prolonged operation. Such a combined materials-morphology-interface perspective provides a framework for translating high OSC efficiencies into longer and more predictable device lifetimes.