Considering the projected increase in demand for protein sources, finding alternative sources with lower environmental impacts has become of great importance. Insect mass production has emerged as a potential solution, particularly in Western countries. Previous studies indicate that insect farming together with insect processing stages are responsible for most of the environmental impacts associated with the final product. This study compares the environmental impacts linked to alternative processing technologies for insect protein production to traditional ones using a Life Cycle Assessment (LCA) following the Environmental Footprint methodology. The most relevant impact categories were identified as land use, energy use, freshwater ecotoxicity, water use and climate change. Among the processing treatments, FOP (freezing–oven drying–hot pressing) showed the best environmental performance in terms of all selected impact categories except water use, while the BOS (blanching–oven drying–SFE with CO₂) group had the highest environmental impacts in all categories. The results from this study indicate that the environmental impacts of insect protein production can be reduced by using alternative processing technologies. These findings underscore the importance of carefully selecting processing technologies in order to align with global sustainability ambitions in the food industry. This study contributes to the development of ecologically responsible methods that can be adopted across protein production industries.

The cultivation of white button mushrooms (Agaricus bisporus) generates significant quantities of spent mushroom substrate (SMS), a byproduct traditionally treated as waste despite its nutrient- and organic-carbon-rich composition. The EU-funded project FER-PLAY identified SMS as one of the most promising circular fertilizers (i.e., those produced from waste streams, transforming them into value-added products). Within the project, a life cycle assessment (LCA) and life cycle costing (LCC) analysis of SMS were conducted with a cradle-to-gate-to-grave scope across three European regions, comparing it to a non-renewable mix with equivalent N, P, K, and C inputs. The LCA results reveal substantial environmental benefits of SMS over the non-renewable baseline, particularly in land use, fossil resource depletion, freshwater ecotoxicity and climate change, which together account for 98% of total impacts. Although SMS exhibits higher water consumption, it represents only 2% of total impacts. LCC highlights the critical effects of fresh mushroom substrate composition on yield, economies of scale, and revenue generation. Overall, this study highlights the significant environmental and economic potential of repurposing SMS as a soil improver, offering a compelling case for its integration into agricultural systems as part of a sustainable, circular economy.

Wastewater treatment plant effluents can be an important source of contamination in agricultural reuse practices, as pharmaceuticals are poorly degraded by conventional treatments and can enter crops, thereby becoming a toxicological risk. Therefore, advanced tertiary treatments are required. Ozone (O₃) is a promising alternative due to its capacity to degrade pharmaceutical compounds, together with its disinfecting power. However, mass transfer from the gas to the liquid phase can be a limiting step. A novel alternative for increased ozone efficiency is the combination of micro-nano bubbles (MNBs). However, this is still a fairly unknown method, and there are also many uncertainties regarding their implementation in large-scale systems. In this work, a combined O₃/MNBs full-scale system was installed in a WWTP to evaluate the removal efficiency of 12 pharmaceuticals, including COVID-19-related compounds. The results clearly showed that the use of MNBs had a significantly positive contribution to the effects of ozone, reducing energy costs with respect to conventional O₃ processes. Workflow and ozone production were key factors for optimizing the system, with the highest efficiencies achieved at 2000 L/h and 15.9 gO₃/h, resulting in high agronomic water quality effluents. A first estimation of the transformation products generated was described, jointly with the energy costs required.

Wastewater reuse presents a promising way to mitigate the risk to global water resources and achieve sustainability in water, especially in agricultural areas in the southeast of Spain, such as the Murcia region. However, the risks related to the presence of contaminants of emerging concern (CECs) or pathogenic microorganisms in wastewater treatment plant (WWTP) effluent suggest the need to implement effective and relatively low-cost tertiary treatments. With this aim, a self-sustainable pilot prototype based on three combined modules (disc-filtration, granular activated carbon (GAC) bed adsorption and UV disinfection) assisted by solar panels was installed as an alternative tertiary treatment in a conventional WWTP in the Murcia region. The obtained results clearly confirmed the efficiency of the proposed prototype for CECs removal, and showed optimal results at a workflow of 500 L/h. In all cases, high removal efficiency was obtained for the different indicator microorganisms described in the recently published Regulation (EU) 2020/741 (E. coli, F-specific coliphages, somatic coliphages, total coliphages, and Clostridium perfringens). The protection of the activated carbon by disc-filters and the energy autonomy and self-operation of the prototype resulted in an efficient and economically viable methodology for its implementation in both conventional WWTPs and in isolated areas attached to crops.

The VALUEWASTE project can offer a sustainable solution to transform biowaste into added-value bioproducts, such as proteins from microorganisms and insects and biofertilizers. The present study focused on the environmental impacts linked to obtaining these bioproducts, which was performed by the standardized Life Cycle Assessment (LCA) approach, using the Environmental Footprint methodology to evaluate the midpoint impact categories considered. At the same time, the bioproducts coming from biowaste were compared to regular ones: other protein sources and mineral fertilizers. The study results show that these new protein sources are firm candidates to reach the market from an environmental point of view. Furthermore, their environmental impacts could be improved by reducing the energy use (the main contributor) within some impact categories, such as ecotoxicity and global warming. In case of the biofertilizers, their environmental performance was overall worse compared to mineral fertilizers, except for the following impact categories: mineral and metal use and water scarcity. Nevertheless, these biofertilizers come from biowaste, extending the circularity concept, and from local places, reducing the dependency on other actors. Hence, the study showed that the obtained bioproducts are real alternatives to implement in a circular economy. However, continuous improvement of the solution should be performed.

The transition to the circular economy (CE) is one of the EU’s current strategic policies to improve its competitiveness and sustainability. While the EU has developed a framework for monitoring overall progress toward the CE, there are gaps in monitoring specific priority sectors, such as the bioeconomy. In order to support industry and policymakers in this sector, this paper presents the application of the BIORADAR’s product circularity monitoring framework to five bio-based fertilizers. The framework is composed of two publicly available indicators: the circular index and the circularity indicator of nutrient; and two new indicator proposals: the biodegradable content and the nutrient slow-release index. Making use of life cycle inventories and supplementary data from the scientific literature, these four indicators were calculated for algae biomass, compost, feather meal, spent mushroom substrate, and wood vinegar. The framework proved to be useful for measuring the circularity at the product level for bio-based fertilizers, especially shedding light on the virgin non-renewable materials consumption, waste generation, biodegradability, nutrient recovery process efficiency, and nutrient release speed. It constitutes the first approach to measuring circularity tailored to bio-based fertilizer. By incorporating it into eco-design, innovation, and managerial decision-making processes, key stakeholders can rely on guiding metrics to support their transition toward higher circularity levels.