The Kuznets Environmental Curve (EKC) hypothesis posits that environmental degradation intensifies during the early stages of economic development and subsequently declines once a critical income threshold is reached, resulting in an inverted-U-shaped relationship between income and environmental pressure. Ecuador and Mexico provide contrasting empirical contexts for examining these dynamics. The Ecuadorian economy remains heavily dependent on natural resource extraction, particularly oil and mining. In contrast, Mexico's economy is more diversified, combining industrial, service, and agricultural activities, yet it still faces persistent environmental challenges. This study assesses the empirical validity of the EKC in both countries over 2007-2024 by analyzing the relationship between economic growth and CO₂ emissions using spatial autoregressive (SAR) and spatial error (SEM) models. Recent subnational data, transformed in logarithmic form, were used to capture regional heterogeneity and improve the interpretation of spatial economic-environmental linkages. The results suggest that Ecuador remains in the ascending phase of the EKC. In contrast, Mexico exhibits a trajectory that approximates the expected inverted-U shape, indicating that some regions may have reached their tipping point. In addition, spatial dependence in Ecuador is strong and concentrated in extractive areas, while in Mexico, it is weaker and reflects a more diffuse and heterogeneous pattern of emissions

Expansive soils represent one of the major challenges in geotechnical engineering due to their unpredictable shrink–swell behavior, which compromises the structural stability of buildings and complicates their use in construction projects. This phenomenon, influenced by seasonal climate variations, is expected to worsen under projected climate change, which is characterized by extreme precipitation and greater thermal variability, significantly increasing the risk of structural damage.

Conventional stabilization methods, such as the exclusive use of lime or salts, present limitations: they require large quantities of material, generate environmental impacts, and do not always guarantee sustainable improvements. This study proposes an innovative approach that combines sodium chloride (NaCl) and lime sludge (LS), a by-product from water treatment plants, to improve the properties of expansive soils while aligning with circular economy principles. Mixtures were prepared with 3%, 6%, and 9% NaCl and 5%, 10%, and 15% LS. Laboratory tests—including Atterberg limits, free swell, swelling pressure, swelling percentage, and infiltration—were conducted to evaluate changes in the soil’s swelling characteristics.

The results show reductions of up to 35% in liquid limit and 65% in free swell. Furthermore, the reduction in plasticity index was up to 36%. In addition, infiltration was 40 mm at the beginning and became 25mm, contributing to better hydraulic stability. Many tons of lime sludge were utilized in the project. By incorporating the lime sludge directly into the treated soil, the material was diverted from potential landfill disposal, thereby reducing the volume of waste generated and lowering the emissions normally associated with conventional waste management practices.

This approach offers a more efficient, cost-effective, and sustainable technical solution, distinguished by its dual action (chemical and recycling) and its contribution to waste valorization. Future research will focus on validating the method at the pilot scale and assessing its performance under extreme climatic conditions, consolidating its applicability in resilient infrastructure projects.

Introduction
Phosphate pollution from industrial wastewater remains a critical threat to aquatic ecosystems due to eutrophication and nutrient imbalance. Addressing this challenge requires sustainable and locally adaptable solutions. This study presents an environmentally conscious approach to converting brewery sewage sludge—an abundant local waste in Gondar, Ethiopia—into activated carbon for phosphate removal. The concept integrates waste valorization with circular water management, reducing disposal burdens while producing efficient adsorbent materials.
Materials and Methods
Sewage sludge was chemically activated using phosphoric acid (H₃PO₄) and sodium hydroxide (NaOH), followed by controlled thermal treatment. Physicochemical properties were analyzed using FT-IR, BET surface area, pHₚzc, and proximate analysis. Batch adsorption tests were optimized via Response Surface Methodology (Design Expert 13.0.5) under varied pH (3–10), contact time (60–120 min), and adsorbent dosage (1–3 g).
Results
The H₃PO₄-activated carbon exhibited a highly porous structure (427.32 m²/g) and achieved 80.3% phosphate removal with an adsorption capacity of 13.6 mg/g at optimal conditions
(pH 3, 120 min, 2.6 g). Adsorption followed the Langmuir isotherm and pseudo-second-order kinetics, indicating chemisorption on a uniform surface. The regenerated adsorbent retained over 50% efficiency after three reuse cycles, confirming its operational stability.
Conclusions
This work demonstrates that brewery sludge—a problematic local waste—can be transformed into a high-value, reusable adsorbent for water purification. The approach supports both environmental protection and resource efficiency, offering a scalable, low-cost pathway toward cleaner water and circular economy practices. It exemplifies how local waste can become a local solution to global environmental challenges.

Swine wastewater, composed of farm effluents, poses significant risks to the environment and public health due to its pollutant loads. This wastewater is frequently applied as fertilizer, but repeated use can lead to soil and water eutrophication and contamination. Various pre-treatment techniques have been explored to mitigate these impacts. Electroflocculation has emerged as a promising technique to reduce the pollution load before soil application. This process involves the controlled release of metal ions, which destabilize colloidal particles in the mixture, resulting in an effluent with substantially lower contaminant levels. Electrode material is a critical parameter in the electroflocculation process. Aluminum and iron are the most commonly used electrodes; however, the required exposure time to the electric current is usually long, making the process costly in terms of both time and financial resources. This study investigated the electroflocculation of swine manure using various alternative electrodes (aluminum, stainless steel, carbon, copper, and zinc) to assess the efficiency of contaminant removal under short exposure times and low voltage conditions, aiming to optimize the process. Manure collected from a farm in Palencia (Spain) was treated at 12 volts for 3, 6, and 9 minutes. After the treatments, both treated and control samples were analyzed in the laboratory for pollutants including turbidity, organic matter, phosphorus and other minerals. The results showed that stainless steel and zinc electrodes were particularly effective reducing turbidity (47% - 67%), organic matter (23%), phosphorus (34% -62%), and calcium (27% - 54%) in the effluent after 9 minutes of current exposure. The average energy consumption was 0.36 W/L which was considerably lower than previous studies. However, these electrodes released some heavy metals into the solution, which could be further reduced through a complementary treatment. Overall, electroflocculation using alternative electrode materials with short treatment times appears to be a suitable pre-treatment strategy for swine manure, reducing pollutant loads while maintaining low energy consumption.

Facing structural water stress exacerbated by climate change, Morocco must rethink its water governance model. This study proposes an international benchmarking analysis comparing the Moroccan system with four countries confronting similar climatic constraints: Spain, Australia, Tunisia, and Jordan. The benchmarking is conducted using a multi-criteria governance framework combining institutional, regulatory, and performance indicators, based on official national reports, international databases, and the peer-reviewed literature; the reference countries were selected due to comparable levels of water stress, arid or Mediterranean climates, and the implementation of documented water governance reforms. Despite undeniable achievements, such as an extensive dam policy and widespread access to drinking water (94% in rural areas), Moroccan governance reveals structural deficiencies, including the inactivity of the Supreme Water and Climate Council, limited autonomy of basin agencies, weak enforcement of Laws 10-95 and 36-15, and underutilization of non-conventional resources. The comparative analysis highlights improvement levers inspired by international best practices: Spain’s autonomous Hydrographic Confederations coordinated by the Ministry for Ecological Transition; Australia’s Murray–Darling Basin Authority and innovative water markets combining desalination with integrated demand management, with documented reductions in agricultural water consumption reaching up to 35–40% in certain sub-basins; Tunisia’s National Water Observatory and demand control through the National Water-Saving Program in Irrigation; and Jordan’s Ministry of Water and Irrigation framework for cooperative transboundary water resource management. The results indicate a substantial potential for additional water mobilization in Morocco through ten priority recommendations: revitalizing the Supreme Water and Climate Council, strengthening the autonomy of basin agencies, updating legislative frameworks (Laws 10-95 and 36-15), diversifying resources through desalination and wastewater reuse, deploying water-saving technologies at scale, enforcing the polluter-pays principle, promoting public–private partnerships, adopting progressive tariff systems, and strengthening climate resilience mechanisms.

Due to increasing anthropogenic pressures, significant quantities of heavy metals are released into the environment, posing severe risks to human health because of their persistence, non-biodegradability, and long-term accumulation within ecosystems. This study aimed (i) to investigate the removal efficiency of Cd(II) and Cr(VI) from aqueous solutions using Saccharomyces cerevisiae, an inactive yeast biomass characterized by a high surface-to-volume ratio, wide availability, and low cost, as a biosorbent; and (ii) to evaluate the environmental sustainability of the biosorption process through Life Cycle Assessment (LCA).

The environmental impacts associated with biosorption were quantified across the four phases of the LCA methodology, conducted using Sphera Product Sustainability Solutions Software. The results revealed that the highest environmental burdens, for both Cr(VI) and Cd(II) removal, were recorded in the impact category Ionizing Radiation, with values of 17.8 person equivalents for Cd(II) and 17 person equivalents for Cr(VI), primarily due to the energy-intensive processes and electricity mix linked to biosorption system operation and LCA modeling.

A negative value was identified for Human Toxicity, cancer effects (–38.9 person equivalents) in the case of Cr(VI) removal indicating an apparent environmental benefit in this category employing S. cerevisiae. Conversely, Cd(II) biosorption showed a positive value to potential human toxicity (0.458 person equivalents), reflecting a measurable burden on the environment.

The application of LCA provided a comprehensive perspective on the environmental impacts generated at each stage, highlighting the biosorption phase as the main contributor to the overall environmental performance.

Introduction

Xylella fastidiosa subsp. pauca (Xfp) has caused significant economic losses in European agriculture. Xfp triggers olive quick decline syndrome (OQDS), disrupting the flow of ecosystems, biodiversity, and economic stability. To control Xfp, the EU has implemented quarantine protocols, including eradicating infected plants, vector suppression, and restriction of trade barriers in plant material. In this context, using Machine Learning (ML) technologies can help control pest pressures, while Deep Learning (DL) algorithms can detect spectral signatures in leaf reflectance caused by infection with over 90% accuracy.

Aim and methodology

This systematic review analyzes the application of ML for the early detection of Xfp. Academic databases (Scopus, PubMed, and ScienceDirect) were searched using keywords such as “Xylella fastidiosa,” “plant disease,” and “machine learning.” Only peer-reviewed studies published between 2015 and 2022 discussing the use of ML for Xfp or OQDS diagnosis in olives were selected. Those focused exclusively on unrelated pests or generic Artificial Intelligence (AI) applications were excluded. A total of 17 studies satisfied the inclusion criteria.

Results

ML enables an adaptive, data-driven, and efficient method of farming. The major input here is a review-based study that uses hyperspectral imagery technology and thermal data from Unmanned Aerial Vehicles and satellites. The most popular models applied are supervised ML algorithms and DL architectures. Yet, these analyses were conducted with small datasets or under controlled laboratory conditions without adequate validation at a large scale in the field, thus impacting the generalization of the results. Further barriers to entry include cost of data acquisition, farmer uptake, regulatory obstacles, and interoperability issues.

Conclusion

ML-enabled sensing technologies complement and supplement existing phytosanitary measures with precision agriculture support for crop health, water use, and Xfp detection. The success factors are early detection and strong field validation involving regulatory and farm-level decision-making frameworks.

Against the background of global warming, a scientific assessment of the spatiotemporal patterns of regional carbon emissions is crucial for achieving the "Dual Carbon" goals (carbon peak and carbon neutrality). Using counties in Jiangsu Province as a typical case study, a county-level carbon emission estimation model was constructed based on DMSP-OLS and NPP-VIIRS nighttime light data and the IPCC carbon emission coefficient method. The model was validated using energy consumption statistics from the China Carbon Accounting Database, showing a high goodness of fit (R² = 0.966) with statistical data and a mean relative error of 4.48%, indicating high reliability. On this basis, methods including spatial autocorrelation analysis and carbon emission economic contribution coefficient were employed to systematically reveal the spatiotemporal evolution characteristics of carbon emissions. Six indicators—Regional GDP, Industrial Structure, Total Population, Urbanization Rate, Energy Structure, and Energy Intensity—were selected to explore the driving factors of carbon emission expansion using the geographical detector technique, identifying both single-factor and interactive effects. The results demonstrate that between 2000 and 2019, carbon emissions in Jiangsu Province generally exhibited a spatial distribution pattern of "high in the south and low in the north," with high-value areas concentrated in the economic core zone of Southern Jiangsu, while the global spatial agglomeration effect showed a weakening trend. Analysis reveals that the level of economic development and industrial structure are the dominant factors driving the spatial heterogeneity of carbon emissions, with significant interactive enhancement effects observed between factors. Finally, considering the combined effects of market regulation and environmental policy, differentiated emission reduction strategies were proposed to provide a scientific basis for regional low-carbon transition and sustainable development.

The shift to sustainability and the circular economy (CE) in the construction industry is essential for reducing its environmental impact, especially in resource-intensive industries such as buildings. Prefabrication, especially modular construction, is gaining popularity in Germany because of its benefits, which include reduced on-site waste production and quicker assembly. It is supported by strong EU and national policies, such as the Circular Economy Act and the EU Circular Economy Action Plan. Studies on the practical implementation of the principles of the circular economy (CE) and the 10R model in the context of German modular construction are particularly scarce. However, emerging studies from other countries, such as Australia, have begun to explore these areas more extensively in recent years. The proposed systematic literature review (SLR) will be used to synthesize the available academic literature, industry reports, and case studies published between 2015 and 2025 to determine the most critical challenges and approaches related to the implementation of the 10R framework in modular construction. In accordance with PRISMA, extensive searches will be performed via Scopus, Web of Science, and German-specific databases, including the BMU reports. The literature retrieved will be subjected to thematic analysis to categorize the findings based on short-, medium-, and long-loop circular applications so that the operationalization of the principles of the circular economy in the modular construction environment can be structured. This study aims to address gaps in the existing literature to identify the barriers to integrating policy, technical, and industry awareness and suggest strategies for integrating them, including the design for disassembly (DfD), collaboration among stakeholders, and tracking materials with digital tools. Finally, it adds to both theory and practice by informing policy developments based on the National Circular Economy Strategy of Germany, capacity building, and future empirical research as a basis for facilitating the transformative adoption of CE in modular construction.

Phenol remediation from contaminated effluents presents a critical industrial challenge due to its acute toxicity even at trace concentrations [1-3]. Multi-walled carbon nanotubes (MWCNTs) are promising adsorbents for this purpose, given their high adsorption capacity and ease of separation [4]. This work presents a phenomenological and numerical analysis of mass transport coupled to phenol adsorption on MWCNTs (d_ext = 50 nm) parameterized with published experimental equilibrium data under neutral pH conditions at 298 K [1,4, 5]. The mathematical model incorporates effective pore diffusivity (D_e = 4.82 × 10⁻¹⁰ m²/s) derived from pore structure parameters and describes three distinct scenarios: (1) pure physical adsorption via modified Fick's Second Law, (2) kinetics incorporating 0.5-order reaction kinetics, and (3) parametric analysis of particle size (1–100 nm) and concentration sensitivity (1–5 mg/L). Numerical solutions establish a Thiele modulus of ϕ ≪ 1 across the tested range, indicating kinetically controlled mass transfer with effectiveness factor η = 1.0, and validate the theoretical dependence ϕ ∝ Cs⁻⁰·²⁵. During effluent polishing operations (reduction from 5 to 1 mg/L), relative diffusive resistance increases by 49.5%, necessitating proportional increases in contact time or adsorbent dosage. The nanoscale architecture of MWCNTs reduces diffusional limitations by approximately 10⁶ compared to macroscopic granular adsorbents, enabling significantly reduced contact times. This phenomenological analysis provides fundamental mass transport insights for optimizing phenol remediation systems using nano-adsorbents.

References

[1] Surkatti, R., Al-Zuhair, S. Microalgae cultivation for phenolic compounds removal. Environ Sci Pollut Res 25, 33936–33956 (2018). https://doi.org/10.1007/s11356-018-3450-8

[2] Abhilasha Rai, Aniket Sen, Biswajit Sarkar, Jitamanyu Chakrabarty, Bikash Kumar Mondal, Susmita Dutta; Phycoremediation of pollutants from secondary treated coke-oven wastewater using poultry litter as nutrient source: a cost-effective polishing technique. Water Sci Technol 1 November 2021; 84 (9): 2406–2421. doi: https://doi.org/10.2166/wst.2021.433

[3] Moraes, F. D. de, Figueiredo, J. S. L. de, Rossi, P. A., Venturini, F. P., & Moraes, G. (2015). Acute toxicity and sublethal effects of phenol on hematological parameters of channel catfish Ictalurus punctatus and pacu Piaractus mesopotamicus. Ecotoxicology and Environmental Contamination, 10(1), 31–36. https://doi.org/10.5132/eec.2015.01.05

[4] Abdel-Ghani, N. T., El-Chaghaby, G. A., & Helal, F. S. (2015). Individual and competitive adsorption of phenol and nickel onto multiwalled carbon nanotubes. Journal of advanced research, 6(3), 405-415. https://doi.org/10.1016/j.jare.2014.06.001

[5] Plugatyr, A., & Svishchev, I. M. (2011). Molecular diffusivity of phenol in sub-and supercritical water: application of the split-flow Taylor dispersion technique. The Journal of Physical Chemistry B, 115(11), 2555-2562. https://doi.org/10.1021/jp1107075