Lactic acid (LA) is an organic acid produced by fermentation or chemical synthesis. It plays a crucial role in the pharmaceutical, food and plastic industries. In the fermentation of, for example, grass silage, LA and different compounds are produced. To purify lactic acid, researchers have tried to investigate membrane technology to achieve a high yield of lactic acid permeance. This study tested four commercially available nanofiltration membranes (NF270, MPF-36, Toray NF, and Alfa Laval NF). Nanofiltration experiments were performed to investigate the rejection levels of lactic acid from a binary solution by using distinct molecular weight cut off membranes. All of the experiments were conducted with a lab-scale cross-flow membrane unit. Different operating conditions (pH, temperature) were studied for each membrane; the optimal process condition was found at 25 °C and pH 2.8. With higher temperatures and pH, an increase in LA rejection was observed. The MPF-36 membrane shows the lowest lactic acid rejection yield of 7%, while NF270 has the highest rejection yield of 71% at 25 °C and pH 2.8. These results will be helpful in the future to understand both the interaction of lactic acid permeance through nanofiltration membranes and process scale-up.

Food production is the main challenge for developing arid regions due to the restricted access to fresh water. This study combines the environmental know-how of two coastal desert regions on the American continent with similar geographical characteristics to propose a general model for a circular economy in stressed environmental conditions. The Atacama Desert, located in Chile, is the driest place on Earth. Due to the lack of rainfall in decades, the possibility of growing food is almost impossible. The Desert of Sonora, in the northwest of Mexico, is known for its extreme aridity and temperatures over 50 °C in summer. Both deserts have continuously growing cities ranging from 400,000 to 900,000 inhabitants, where access to and management of freshwater represents an issue. A circular economy model was developed. Critical parameters for this model considered: the utilisation of solar energy for water desalination and energy production, integrated with hydroponic farming and water dosing with hydrogels for food production; microalgae for biofuels; seaweed for biochemicals; anaerobic digestion for organic waste management and nutrient recovery from wastewater sludge treatment. Regional policies and governance are needed to incentivise the adoption of circular economy models.

The Transformer project at TU Wien exemplifies how universities can act as initiators for sustainability education and STEM science communication. Addressing the urgent need for climate change adaptation and the strengthening of key competencies for sustainability, this paper examines the university’s role in creating a temporary, participatory learning space. The Transformer bridges academic research and societal practice, demonstrating how higher education institutions can actively shape sustainable development. As both a knowledge producer and a facilitator of public dialogue, TU Wien designs the Transformer as a hands-on laboratory for children and adolescents, providing low-threshold access to STEM and sustainability content. By integrating university students and researchers from architecture, civil and environmental engineering, mechanical engineering, electrical engineering, informatics, and technical chemistry, the project transforms abstract scientific concepts into tangible, co-created solutions. This approach is designed to foster systemic thinking, practical skills, and participant agency—outcomes for which this paper presents documented but preliminary evidence—while enriching academic teaching and research through real-world applications. This paper analyses how TU Wien’s commitment to interdisciplinary cooperation and participatory science communication positions the Transformer as a model for other institutions, with a focus on circular economy as the anchor theme. Through reflective practice on four analytical dimensions—place-based learning, staged sustainability education, co-creative STEM communication, and the engaged university—this study offers insights into the challenges and opportunities of university-led co-creation spaces and considerations for institutions seeking to develop comparable initiatives.