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.

Biorefinery systems play a critical role in the transition towards a sustainable bioeconomy, and bioreactors are a key component in these systems. While mechanically stirred reactors have been extensively studied, there is a lack of research on pneumatically driven systems like air-lift reactors (ALRs). This study aims to address this gap by examining the hydrodynamic behavior of a double draft tube airlift bioreactor using Computational fluid dynamics simulations. Ten different geometric configurations were investigated, with variations in draft tube placement, liquid height, distance between draft tubes and draft tube diameters. Results showed that the placement of the draft tubes heavily influenced hydrodynamic behavior, with smaller distances between draft tubes and a funnel configuration leading to higher velocities. Stable downcomer velocities were achieved by maintaining a consistent distance between the bottom clearance and the sum of the distance between draft tubes and the bottom clearance on the top clearance. The model was validated against literature experimental data. This study provides insight into the optimal design of ALRs, which can contribute to the development of more efficient and effective bioreactor systems. The findings can be used to forecast the most optimal configurations of airlift bioreactors and have significant value for the development of more efficient biorefining concepts in light of the increasing importance of studying biorefineries and their components in the shift towards a biomass-based economy.

Underground wine cellars represent a fragile form of cultural heritage, where long-term microclimatic imbalance can lead to material degradation, structural instability, and internal collapses. High humidity, limited ventilation, and the difficulty of access complicate both diagnosis and conservation. This study presents preliminary results from a preventive monitoring strategy applied to the underground wine cellars of Baltanás (Palencia, Spain), focusing on temperature, relative humidity, wall moisture content, and ventilation as key drivers of deterioration. A wireless network of commercial temperature–humidity sensors, wall moisture probes, and airflow sensors was deployed in four sections of a representative cellar over a monitoring period exceeding two years. In addition, mobile monitoring was performed using a quadruped robot equipped with a rotating environmental sensing module, enabling measurements in confined and unstable areas. Results reveal strong thermal inertia, persistently high relative humidity frequently approaching saturation, low and intermittent natural ventilation, and sustained internal wall moisture. These conditions are consistent with observed material decay and internal landslides. The monitoring with quadruped robot proved particularly valuable for identifying localized humidity pockets and stagnant air zones beyond the reach of fixed sensors. The study demonstrates how different solutions for monitoring can support preventive conservation strategies for subterranean heritage, providing a scalable framework for early risk detection and informed management decisions.

In this paper the design, development, and validation of a set of low-power low-cost sensor systems intended for environmental monitoring and visitor tracking in cultural heritage sites are shown. These systems have been deployed in five pilot cases in four different countries in Europe inside the European ARGUS project. Two different approaches have been defined in the design: the static systems installed in fixed positions and the dynamic systems installed in a moving robot, i.e., a quadruped robot or a drone. The Baltanás pilot site has served as the primary testing platform, enabling accelerated prototyping and iterative improvement before deployment across additional pilot locations. This paper presents the design criteria, system architectures, and performance evaluation of these sensor networks, including thermal–humidity probes, volumetric water content sensors, wind measurement systems, pollution monitors, and two generations of visitor counting devices.

In this paper the design, development, and validation of a set of low power, low-cost sensor systems intended for environmental monitoring and visitor tracking in cultural heritage sites is shown. These systems have been deployed in 5 pilot cases in 4 different countries in Europe inside the European ARGUS project. Two different approaches have been defined in the design: the static systems installed in fixed positions and the dynamic systems installed in a moving robot i.e., a quadruped robot or a drone. The Baltanás pilot site has served as the primary testing platform, enabling accelerated prototyping and iterative improvement before deployment across additional pilot locations. This paper presents the design criteria, system architectures, and performance evaluation of these sensor networks, including thermal–humidity probes, volumetric water content sensors, wind measurement systems, pollution monitors, and two generations of visitor counting devices.