Pavement construction relies heavily on natural aggregates and conventional stabilizers such as Portland cement (PC) and lime, contributing to resource depletion, high energy demand, and significant greenhouse gas emissions. Geopolymerization, the alkaline activation of aluminosilicate materials, offers a more sustainable alternative. Mine tailings (MT), abundant mining by-products rich in silica and alumina, are attractive geopolymer precursors, although their reuse is constrained by variable composition and potential toxicity. In mining-intensive countries like South Africa, copper, cassiterite, and gold MT represent promising resources. This review critically synthesizes current knowledge on the physicochemical properties, mechanical performance, and environmental implications of geopolymerized MT in pavement applications. Unlike previous reviews that consider MT or geopolymers in isolation, it establishes a pavement-engineering–driven framework linking MT characteristics, geopolymer chemistry, and pavement performance requirements across laboratory, environmental, and field scales. The reviewed evidence indicates that MT-based geopolymers can achieve higher strength and superior durability than PC or lime-stabilized bases while reducing CO2 emissions by up to 80
To review the current advances, persistent challenges, and future prospects of methanol fuel cell technologies, thereby supporting the transition toward low-carbon energy systems. This is a comprehensive review that analyzes recent global progress across key aspects of methanol fuel cell technology. The focus areas include catalyst development, membrane innovation, performance optimization, and system integration. Recent advances in electrocatalysts, nanostructured membranes, and hybrid system designs have substantially enhanced the efficiency, durability, and operational flexibility of methanol fuel cells. This progress has enabled their expansion in transportation, portable electronics, stationary power, and industrial energy generation. This review offers a holistic overview of the current state-of-the-art and identifies critical limiting factors, such as methanol crossover, limited long-term durability, and high production costs, that continue to constrain commercialization. It emphasizes the need for coordinated, multidisciplinary efforts in materials science and system engineering, alongside favorable policies, to accelerate adoption and position methanol fuel cells as an integral component of the future renewable-energy landscape.
Nanofertilizers represent an emerging class of smart agro-inputs designed to enhance nutrient use efficiency, crop productivity, and environmental sustainability. Unlike conventional fertilizers, they consist of nanoscale nutrient carriers or particles (1–100 nm) that enable targeted delivery, controlled nutrient release, and improved uptake by plants. Their higher surface-area-to-volume ratio enhances nutrient solubility and mobility in the rhizosphere, reducing fertilizer losses through leaching, volatilization, and runoff. Nanofertilizers such as nano-nitrogen, nano-phosphorus, nano-potassium, micronutrient nano-chelates, polymeric nanocarriers, and carbon-based nanofertilizers have demonstrated significant potential in improving plant physiological responses, photosynthetic activity, and yield. In addition to enhancing crop productivity, nanofertilizers improve soil fertility by stimulating beneficial microbial populations, promoting enzymatic activity, and supporting long-term soil health. Their application aligns with precision agriculture through integration with remote sensing technologies and site-specific nutrient management systems. However, challenges such as potential nanoparticle toxicity, bioaccumulation in edible crops, limited field-scale validation, lack of regulatory guidelines, and high production costs remain barriers to large-scale adoption. This review summarizes recent advancements in nanofertilizer synthesis, mechanisms of action, application strategies, and environmental interactions, along with associated risks and future prospects to ensure safe and sustainable agricultural intensification.
Chlorinated paraffins (CPs), complex polychlorinated alkanes, are persistent organic pollutants (POPs) of growing concern. They are used as flame retardants, plasticizers, and lubricants, and enter agroecosystems via wastewater irrigation, sewage sludge, atmospheric deposition, and industrial runoff, exhibiting strong sorption, long half-lives, and bioaccumulative potential. While short-chain CPs (SCCPs) are regulated under the Stockholm Convention, medium- and long-chain CPs (MCCPs, LCCPs) are increasingly detected in soils, sediments, and crops but remain poorly categorized for toxicity and environmental fate. Evidence indicates that CPs can alter soil microbial diversity, inhibit enzymatic activity, disrupt nutrient cycling, and accumulate in plants, posing risks of food-chain transfer and human exposure. However, significant knowledge gaps persist regarding their long-term ecotoxicological impacts, degradation and transformation processes, and interactions with soil organic matter that govern their mobility, persistence, and bioavailability. This review discusses the existing literature on CP occurrence, fate, and ecological effects in agricultural environments, emphasizing analytical techniques and monitoring approaches for assessing soil-plant-human exposure, and identifies key research needs. Addressing these gaps is essential for improving risk assessment, guiding regulatory development, and protecting soil health, crop productivity, and food safety. CPs represent a “silent contaminant” in agriculture, threatening soil health, crop productivity, and food safety. Future research should integrate advanced detection methods, pilot-scale remediation strategies, and comprehensive risk assessments to inform policy, protect vulnerable populations, and safeguard sustainable agricultural production.
Balancing energy security, energy equity, and environmental sustainability has become increasingly challenging as economies pursue low-carbon growth amid climate risk and persistent disparities in access to modern energy. Although entrepreneurship is widely recognized as a driver of innovation, its role in addressing the energy trilemma remains contested. This study examines whether, and under what conditions, entrepreneurship contributes to resolving the energy trilemma, using panel data for 64 countries from 2011 to 2022. Drawing on the World Energy Council's trilemma indices, World Bank entrepreneurship and macroeconomic indicators, and OECD-DAC climate finance data, the analysis employs random-effects models to capture both within- and between-country variation. The results show that entrepreneurial activity is robustly associated with improved energy security and energy equity, alongside more modest gains in environmental sustainability. Innovation capacity strengthens these relationships, while foreign direct investment and climate finance exhibit uneven effects, tending to support system-level and environmental outcomes more than inclusive access. Regulatory quality emerges as a critical enabling condition that significantly amplifies the positive impact of entrepreneurship across the energy trilemma. Overall, the findings provide cross-country evidence that entrepreneurship functions as both an innovation conduit and a decentralizing force in energy transitions, underscoring the importance of predictable regulation and better-targeted climate finance for access-oriented clean energy solutions.
