The increase in industrial production and the use of synthetic dyes has become one of the main sources of water pollution in recent decades. The textile industry, in particular, is responsible for discharging large volumes of wastewater with a high pollutant load, with estimates indicating that around 14,000 tons of dyes are released annually into the environment without proper treatment. These compounds exhibit high chemical stability and resistance to biodegradation, allowing them to accumulate in aquatic organisms and affect the entire food chain. Furthermore, they alter the physicochemical properties of water, such as pH and turbidity, and may contain toxic, mutagenic, or carcinogenic substances.

In this context, the development of sustainable wastewater treatment technologies has become essential to minimize environmental risks and preserve water resources. This study aimed to produce activated carbons (ACs) from Mozambican agricultural waste through chemical activation with potassium hydroxide (KOH), evaluating their efficiency in removing crystal violet (CV) dye from aqueous solutions. To optimize their adsorptive properties, ACs were simultaneously activated with KOH and a nitrogenous compound (urea) to increase porosity and specific surface area.

Three natural precursors were used, with a ratio of 1:2:1 (precursor: activating agent: urea). Kinetic adsorption tests were carried out at 298 K and pH 6 for 168 hours. Adsorption isotherms were determined using 10 mg of modified ACs added to 25 mL of CV solution (0–250 mg/L) under constant stirring at 20 rpm for 24 hours, ensuring equilibrium between the liquid and solid phases. The results showed high efficiency in removing the dye, with the sample prepared at a 1:2:1 ratio displaying the best adsorptive performance, a more porous structure, and a larger surface area. In contrast, the 1:2:0.5 ratio presented a lower adsorption capacity, likely due to reduced incorporation of nitrogen functional groups in the material matrix.

Pollution from micro- and nanoplastics currently represents one of the main environmental challenges, raising concerns both for its ecological consequences and for the potential risks to human health. After two decades of data collection since the first appearance of the term “microplastic” in the scientific literature, research is moving toward a new direction—that of assessing ecological and human health risks. In this perspective, a rising interest is converging on the use of indices, which may represent an effective tool for describing environmental quality in a clear and straightforward manner.

This contribution, based on the systematic review of 316 papers collected from the Web of Science database, aims to examine the use of indices for environmental risk assessment from both an editorial perspective (when the first publication dates back to, how the topic has evolved over time, and which publishers and journals have shown the greatest interest) and a technical point of view (which and how many indices have been proposed to date, which environmental matrices have been considered, and which geographical areas have received the most attention). Furthermore, what limitations does each index present, and how can they be improved? The goal is to gather and summarize all information on the topic, which to date remains somewhat fragmented, and propose a roadmap to guide researchers and practitioners through an informed, accurate, and standardized use of indices for ecological risk assessment of microplastic pollution.

Fruit and vegetables are among the food groups with the highest post-harvest losses, with an estimated 40% of production discarded worldwide. This organic waste significantly contributes to greenhouse gas emissions, particularly methane, during decomposition, emphasising the need for sustainable and circular strategies to valorise resources. This study aimed to develop a sustainable method for producing antimicrobial peptides (AMPs) from fruit peel waste using genetically modified Saccharomyces cerevisiae expressing the Ethanol Red TDH1 (ER TDH1) gene and to evaluate their potential against microbial pathogens.

Waste peels of mango, pineapple, banana, and apple were processed into must. The musts underwent acid hydrolysis, followed by alcoholic fermentation with S. cerevisiae ER TDH1. After fermentation, peptides <10 kDa were extracted from the cell-free supernatant by ultrafiltration and tested against microbial pathogens, including E. coli, P. aeruginosa, S. aureus, and C. albicans. Glucose, fructose, and ethanol levels were monitored throughout. For peptide production comparison, alcoholic fermentation of a synthetic must was performed, yielding higher ethanol (14 g/L) than fermentation of fruit must (3 g/L). The <10 kDa peptide fraction from fruit must showed strong inhibition of S. aureus and C. albicans (MIC = 1.47 mg/mL), while synthetic must peptides performed better against E. coli and P. aeruginosa (MIC = 1.47 mg/mL). AMPs derived from fruit waste via fermentation show promising antimicrobial activity, particularly against Gram-positive bacteria and yeast, highlighting their potential as sustainable, natural antimicrobial agents for pharmaceutical or food product applications, while contributing to circular economy principles by transforming underutilized biomass into high-value bioactive compounds.

Anthropogenic gadolinium, mainly from gadolinium-based contrast agents (GBCAs) used in magnetic resonance imaging, is increasingly recognised as a persistent contaminant in aquatic environments. These chelated compounds are excreted largely unmetabolized and pass through conventional wastewater treatment systems, leading to detectable anomalies in rivers, estuaries, groundwater, and even tap water. Their high stability ensures conservative transport over large spatial and temporal scales. Still, environmental transformation processes may release toxic-free Gd³⁺ ions, raising concerns about ecological impacts, such as sorption to sediments and bioaccumulation. Despite these risks, Gd anomalies serve as valuable hydrogeochemical tracers, enabling the tracking of wastewater plumes, groundwater–surface water interactions, and urbanisation pressures. This dual role—emerging pollutant and useful tracer—has placed anthropogenic Gd under increasing scientific and regulatory scrutiny, yet it remains largely unregulated in water policy.

Addressing this gap, the present study provides the first Portuguese survey of anthropogenic Gd through a multi-basin sampling campaign across five transition aquatic systems: the River Mondego, River Sado, and River Mira (fluvial), and the Ria de Aveiro and Lagoa de Albufeira (lagoon). Through a multi-basin sampling campaign, rare earth element signatures were analysed across five hydrographic basins to establish baseline anthropogenic Gd concentrations, identify potential hotspots associated with urban and hospital effluents, and evaluate the implications of its presence for both water management and environmental health.

Results reveal marked spatial variability in anthropogenic Gd, ranging from 0.32 to 16.9 ng/L, with the highest anomalies detected downstream of densely populated and hospital-influenced areas (Gd/Gd* > 1.5). In contrast, more pristine regions exhibited background signatures (Gd/Gd* < 1.5). These findings not only establish a baseline for anthropogenic Gd concentrations in Portugal but also highlight its dual role: as a promising management tool for tracing wastewater pathways, and as an emerging contaminant with potential ecological implications.

In many regions, including the Kingdom of Saudi Arabia, municipal solid waste is still landfilled without energy or material recovery, resulting in environmental degradation and economic losses. This study evaluates the feasibility and economic potential of integrating composting of organic food waste (OFW) into a circular economy framework, using the City of Jeddah as a case example. The analysis quantifies the financial and environmental benefits of diverting OFW from landfills to a composting facility, including savings from avoided tipping fees, carbon credit gains from reduced methane emissions, and revenues from compost sales and its nutrient substitution value (carbon, nitrogen, phosphorus, and potassium). OFW generation in Jeddah is projected to rise to 1.30 Mton by 2030 due to rapid population growth and urbanization, providing the capacity to produce approximately 0.27–0.32 Mton of compost annually between 2015 and 2030. The proposed system not only mitigates ecological impact but also contributes substantial economic value, with estimated compost sales revenues of MSAR 284–341, environmental savings of MSAR 728–875, and fertilizer replacement benefits of MSAR 87–105 over the study period. By 2030, the composting strategy demonstrates the potential to deliver a net contribution of MSAR 1321 to the national economy. These findings highlight composting as a viable circular economy solution capable of closing material loops, reducing environmental burdens, and generating sustained economic returns for Saudi Arabia’s waste management sector.

The utilization of microalgae for renewable biofuel production offers a promising alternative to fossil fuels mainly because of their rapid growth and high lipid content. Moreover, cultivating microalgae can help capture carbon dioxide and recycle nutrients, especially when integrated into waste management systems. However, environmental conditions significantly affect the productivity and chemical composition of algal biomass. Among these, the harvest season plays a major role, affecting the physiological conditions of the cells and the accumulation of energy-rich compounds. Understanding how seasonal changes affect the biofuel potential is essential for improving production efficiency and ensuring stable large-scale operations.

In this study, we evaluate how the harvesting season affects the yield and composition of biofuels obtained from naturally occurring microalgae grown in an open raceway pond at a biogas producing facility in Sauquillo de Boñices (Soria, Spain). The carbon dioxide from the biogas upgrading and the nutrients from the digestate liquids were used to stimulate microalgae growth. The algal species primarily consisted of Chlorella sp., Scenedesmus sp., and Ankistrodesmus sp. Samples were collected during four distinct seasons and processed under variable drying conditions. Oil extraction was carried out using the Soxhlet method, and the oils were converted to fatty acid methyl esters (FAMEs) through esterification and transesterification. Our findings show that microalgae collected in winter contained the highest lipid levels and energy yields, while samples from warmer months resulted in lower-quality biofuels due to oxidative degradation and limited lipid accumulation. These observations highlight the importance of seasonal control and integrated biorefinery approaches for achieving efficient and sustainable microalgae-based biofuel production.

Wastewater treatment plants (WWTPs) can serve as hubs for converting waste into energy, thereby supporting a city's energy needs. Sewage sludge can be converted into valuable products through thermal processes. In gasification, energy-rich syngas is produced, which can be further valorized to generate electricity. However, the use of air introduces nitrogen as a diluent, thereby reducing the energy density. Integrating electrolyzers for hydrogen production into the process offers an added advantage: the use of oxygen as a gasification agent, thereby reducing dilution. The present work assesses the simulation of a conventional WWTP using Superpro Designer V13. Using pure oxygen in the gasification unit reduces the thermal energy requirements of the process. It increases the energy content by 4% when the system is operated under a CO2 atmosphere and a 25% equivalence ratio (ER: 4.0) for both cases. Water electrolysis is integrated as an energy storage system; therefore, the scenarios analyzed assumed intermittent hydrogen production. This document highlights the importance of advancing research on the use of reclaimed water for hydrogen production, as well as the efficient integration of processes to reduce the energy and water footprints of technologies supporting a green transition.

Life is a race of survival within the environment, where every species depends on others through complex ecological interdependence. Yet, human civilisation has increasingly reshaped natural systems for comfort and progress, often disrupting the balance that sustains biodiversity, climate, and health. Urbanisation and industrial growth create artificial ecosystems that consume vast resources and emit pollutants back into the environment.

This study examines how human development can maintain full living standards while reducing environmental imbalance. It focuses on the carbon and nitrogen cycles as indicators of ecosystem stability and evaluates how urban design affects these fluxes.

A model city (“Flux City”) was developed to simulate a fully supplied urban environment with 100% provision of food, water, power, housing, and waste services. Changes in carbon and nitrogen fluxes were analysed against natural baseline values to quantify human impact. Supporting examples from deforestation in the Amazon, fertilizer-driven greenhouse gas emissions, acid rain in industrial zones, and ocean oxygen decline were also considered to contextualise the findings within global environmental patterns.

Burning of fossil fuels increased from 0.6 to 7.5 × 10⁹ g C y⁻¹, reflecting industrial and transport energy demand. Plant assimilation declined ~18% (163 → 134 × 10⁹ g C y⁻¹), and soil carbon inputs fell ~17%, indicating vegetation loss and soil sealing. Industrial nitrogen fixation rose from 0 to 102 × 10⁶ g N y⁻¹, while leaching and runoff grew >3 times, signaling eutrophication risk. Despite a 100% urban supply, ecosystem resilience decreased, and atmospheric CO₂ rose sharply.

Maintaining human needs without degrading the environment requires integrated solutions: electrification, low-carbon materials, precision agriculture, nutrient recovery, and urban greening. Sustainable survival demands partnership, not dominance over the environment.

ASEAN nations such as Malaysia, the Philippines, and Thailand represent a globally significant nexus of biodiversity and ecological vulnerability. This posits that a fundamental gap exists within the higher education institutions (HEIs) of these nations. Despite the charted policy in the workforce to prepare for green jobs, many ASEAN HEIs often fail to equip both current and future graduates with the interdisciplinary competencies required to tackle complex ecological challenges, along with a strong foundation in biological sciences. This research proposes the Applied Bio-Sustainability Praxis (ABP) model, a novel curriculum model grounded in Mezirow's Transformative Learning Theory. The model provides a structured methodology for HEIs to systematically integrate advanced biological sciences with key sustainability domains, including environmental assessment, circular economics, and biodiversity policy. The research uses a multi-level validation approach that includes a comparative study of the curriculum and semi-structured interviews with prominent scholars in the three countries. Through such triangulation of data, the study aims to define the ABP model as a versatile higher education template of re-engineering biological science education. Empirical research points to a trend of greater education establishments displaying an aura of environmental worry, a kind of greenwashing, as opposed to taking the radical, more systemic, and profound alterations that would be necessary to integrate ESD meaningfully. It is agreed by most high-ranking leaders in the education field that successful ESD requires an interconnected, multidisciplinary, and holistic approach that is not added as an option or siloed curriculum, but instead is embedded in the heart of other disciplines, including biology.

Efficient water management is essential for sustaining vegetation in the arid environment of the United Arab Emirates (UAE), where high temperatures and limited freshwater resources intensify the need for optimized irrigation strategies. This study develops a remote-sensing-based monitoring framework to assess water use efficiency (WUE) across the sparsely vegetated landscape of the Al Ain in the UAE. The vegetation of Al Ain is characterized by date palm cultivation and xerophytic species that are physiologically adapted to the desert, wadi, and mountainous environments. Multi-source satellite datasets—including 30 m vegetation indices from Landsat and Sentinel-1 and 1-km evapotranspiration (ET) estimates from the Simplified Surface Energy Budget (SSEBop)—were integrated to quantify spatiotemporal patterns in vegetation productivity and water fluxes. Vegetation greenness and productivity were evaluated using the Normalized Difference Vegetation Index (NDVI) and Radar Vegetation Index (RVI), while ET data captured seasonal variations in soil evaporation and transpiration. Water use efficiency (WUE), expressed as the ratio of GPP to ET, served as a metric for evaluating biomass production relative to water consumption under hyper-arid conditions. Time-series analyses revealed marked seasonal dynamics in NDVI, RVI, GPP, and ET associated with rainfall pulses and irrigation activities. Spatial mapping highlighted variability in vegetation performance and identified zones with potential for improved water-use optimization. The findings demonstrate the value of Earth-observation-driven analyses in characterizing vegetation responses to extreme precipitation events and irrigation practices. The proposed monitoring tool provides a practical foundation for advancing sustainable irrigation planning, enhancing vegetation carbon uptake, and promoting long-term water resource sustainability in Al Ain, UAE.