Giovanni Dolci

Biodegradable films were prepared starting from milk extracted casein, even in combination with lignin. The films were used to immobilize glucose oxidase from Aspergillus niger and tested to detect the presence of glucose in solution.

Purpose: The life cycle assessment (LCA) performed in this work evaluates the potential environmental impacts of an activated-sludge-based wastewater treatment plant (WWTP) coupled with microalgal cultivation, including the algal biomass recovery. The system is compared with the WWTP without algal integration to evaluate the potential benefits derived by the coupling. In addition to more conventional valorization strategies for the algal biomass, a special focus is given to the production of biostimulants, that give the chance to replace some chemical fertilizers. Method: Four scenarios are compared. They differ in the algal biomass valorization route: direct use in agriculture (S1), incineration with energy recovery (S2), use in cement plant as an auxiliary fuel (S3), and biostimulants production and use on crops (S4). The environmental impacts of the system are assessed including 16 categories, to comprehensively cover its potential impacts. Results: S4 allows for significant impact reductions (compared to the WWTP without algal integration) only when the increase of the nutrient-uptake efficiency of crops is taken into account. Assuming a 5% reduction of fertilizers application, S4 shows an improvement in 14 out of the 16 impact categories. Conversely, when the amount of substituted fertilizers is calculated comparing just the macronutrient content of biostimulants with that of algae, S4 is comparable with S1, S2, and S3, where just four to five impact categories show lower impacts than the WWTP without algal integration. Conclusions: The LCA confirms the environmental benefits of biostimulants application on crops, although the modeling approach requires further research as it strongly influences the results.

In the recent years, packaging made of conventional plastics has been increasingly replaced by materials believed to be more sustainable. However, perceived sustainability must align with scientific assessments, such as life cycle assessments (LCAs). This review analysed 53 peer-reviewed studies published in the time range 2019–2023, aiming at understanding the state of the art in LCA about the environmental impacts of packaging by focusing on the comparison between plastics and alternative materials. The literature showed that consumer perceptions often differ from LCA findings and revealed that, frequently, conventional plastics are not the least environmentally friendly choice. Bioplastics typically show benefits only in the climate change and the fossil resource depletion impact categories. The heavy weight of glass turns out to affect its environmental performances with respect to the light plastics, with reuse being an essential strategy to lower the burdens. The comparison between plastics and metals is more balanced, leaning more towards plastics for food packaging. Similarly, paper resulted often preferable than plastics. Finally, for the other materials (i.e. wood and textiles), the picture is variable. To be competitive with plastics, the alternative materials require improvements like the optimisation of their production processes, their reuse and enhanced end-of-life options. At the same time, recycled polymers could boost the eco-performance of virgin plastics.