The escalating environmental challenges posed by waste rubber tyres (WRTs) necessitate innovative solutions to address their detrimental effects on the geoenvironment. Thus, the knowledge about the recent advancements in material recovery from WRTs, emphasising their utilisation within the framework of the United Nations Sustainable Development Goals (SDGs) and the circular economy principles, is the need of the hour. Keeping this in mind, various techniques generally used for material recovery, viz., ambient, cryogenic, waterjet, and so on, which unveil innovative approaches to reclaiming valuable resources (viz., recycled rubber, textiles, steel wires, etc.) from WRTs and various devulcanisation techniques (viz., physical, chemical, and microbial) are elaborated in this paper. In parallel, the paper explores the utilisation of the WRTs and recovered materials, highlighting their application in geotechnical and geoenvironmental engineering development projects while addressing the necessary environmental precautions and associated environmental risks/concerns. This paper incorporates circular economy principles into WRTs utilisation and focuses on achieving SDGs by promoting resource efficiency and minimising their environmental impact.

This study explores the mechanical properties and synergistic mechanisms of silty sand modified with guar gum (GG) and polypropylene fiber (PP fiber) through a series of unconfined compressive strength (UCS) tests, direct shear tests, and direct tensile tests. The test results reveal that the unconfined compressive strength (UCS) of silty sand can be dramatically improved by incorporating GG, boosting its strength by up to 23 times compared to the natural soil. Adding PP fiber further enhances the UCS and effectively mitigates brittle failure. GG dominates the increase in shear strength by enhancing cohesion, while the PP fiber optimises the shear stability by increasing the internal friction angle. The shear strength of the GG-PP fiber-enhanced soil can be boosted by 235% compared to natural soil. The synergistic effect of GG and PP fibers enables the tensile strength of the improved silty sand to reach 122.75 kPa, representing a 34.15% increase compared to soil with only GG incorporated. However, if the fiber content is too high (> 0.5%), the tensile strength will decrease due to increased porosity. The study found that GG enhances the cohesion between soil particles through hydrated gel, and the PP fiber inhibits crack propagation and improves ductility through the bridging effect. The two form a bonding-bridging synergistic system, which significantly optimises the mechanical properties of the soil. This combined improvement scheme has both high strength and high ductility and can replace traditional inorganic cementitious materials, providing new ideas and methods for the application of silty sand in roadbed engineering, slope reinforcement, and other fields.

United Nations General Assembly declared that 2023 will be celebrated as the International Year of Millets. Millets are a group of coarse grains from the Poaceae family that offer numerous benefits that align with various United Nations Sustainable Development Goals (UN SDGs). This review explores diverse contributions of millet cultivation, consumption, and value addition with UN SDGs. The millets help in combating hunger by providing economical sources of essential nutrients and diversifying diets, improving health through mitigating malnutrition and diet-related diseases. Millet's lower water demand and resilience to climatic stress help in sustainable water management. Millets reduce the risks associated with monoculture farming and promote sustainable agricultural practices. Similarly, millet plants need few chemical fertilizers, and the ecological damage associated with these plants is minimized. Millets can prevent soil degradation and conserve biodiversity. They can adapt to diverse cropping systems and support sustainable land practices. Millet cultivation reduces inequalities by empowering smallholder farmers and maintaining economic balance. The cultivation and trading of millets promote partnerships among governments, NGOs, and businesses for sustainable development. The ability of millet to contribute to poverty reduction, hunger alleviation, health improvement, environmental sustainability, and economic development makes millet a sustainable choice for a better world.

Engineered nanomaterials (ENMs) have aroused extensive interest in agricultural, industrial, and medical applications. The integration of ENMs into the agricultural systems aligns with the principles of United Nations' sustainable development goals (SDGs), circular economy (CE) and bio-economy (BE) principles. This approach offers excellent opportunities to enhance productivity and address global climate change challenges. The revelation of the adverse effects of nanomaterials (NMs) on various organisms and ecosystems, however, has fueled the debate on 'Nano-paradox' leading to emergence of a new research domain 'Nanotoxicology'. ENMs have shown different interactions with biological and environmental systems as compared to their bulk counterparts. They bioaccumulate in organisms, soils, and other environmental matrices, move through food chains and reach higher trophic levels including humans ultimately resulting in oxidative stress and cellular damage. Understanding nano-bio interactions, the mechanism of gene- and cytotoxicity, and associated potential hazards, is therefore, essential to mitigate their toxicological outputs. This review comprehensively examines the cyto- and genotoxicity mechanisms of ENMs in biological systems, covering aspects such as their entry, uptake, cellular responses, dynamic interactions in biological environments their long-term effects and environmental risk assessment (ERA). It also discusses toxicological assessment methods, regulatory policies, strategies for toxicity management/mitigation and future research directions in nanotechnology, all within the context of SDGs, CE, promoting resource efficiency and sustainability. Navigating the nano-paradox involves balancing the benefits of nanomaterials with concerns about nanotoxicity. Prioritizing thorough research on above facets can ensure sustainability and safety, enabling responsible harnessing of nanotechnology's transformative potential in various applications including mitigating global climate change and enhancing agricultural productivity.

This research investigates the stabilization of infinite slopes in the Lesser Himalayan region using nano-silica (NS), employing analytical, numerical, and experimental techniques. The findings demonstrate significant improvements in slope stability, including an 800.3% increase in soil cohesion, a 320% rise in the factor of safety (FOS), and a 75% reduction in pore water pressure. These enhancements ensure the stability and safety of slopes in vulnerable terrains. This study aligns with multiple United Nations' Sustainable Development Goals (SDGs): fostering resilient infrastructure and innovation (SDG 9), enhancing community safety (SDG 11), supporting climate adaptation strategies (SDG 13), conserving land resources (SDG 15), and promoting sustainable material use (SDG 12). By addressing environmental challenges and advancing sustainable geotechnical solutions, this work contributes significantly to global efforts towards resilience and sustainability.

Ozone depletion, global warming, soil degradation, etc., could be, to a great extent, instrumental in making our Earth an unsafe place. Therefore, to prevent further damage, Article 6 of the United Nations Framework Convention on Climate Change (UNFCCC) emphasizes spreading awareness among the members of the planetary community to protect the planet. The study aims to identify teaching pedagogies that can effectively develop awareness and responsibility among university youth for a sustainable future. The study adopts an exploratory triangulation approach and uses three instruments: a closed-ended questionnaire, a focus group interview, and a comparative performance of control and experimental groups. Fifty-one faculties from two government universities of Saudi Arabia: Qassim University, Qassim, and Prince Sattam bin Abdulaziz University, Alkharj along with 47 students pursuing conversation courses at Level Three in Prince Sattam University participated in the study. JASP 0.9 open-source software was used for statistical analysis. The results revealed that constructivist inquiry-based approaches promoted sustainable development education.

Cutting is a fundamental machining method extensively utilized across various fields, including mechanical engineering, agriculture, forestry, biomedical instrumentation, mineral exploration, and extraterrestrial missions. However, during cutting operations, tools are exposed to high temperatures and friction, which result in diminished cutting efficiency, reduced tool life, and compromised workpiece quality. Advances in bionics are gradually mitigating these challenges. Bionic design provides rich, reliable, and efficient prototypes that enhance tool performance while promoting environmentally friendly, harmonious, and sustainable tool development. In the bionic optimization of cutting tools, the selection of appropriate bionic prototypes and models is crucial. However, the complexity and ambiguity inherent in bionic prototype functions impede the development and widespread adoption of bionic tools. This paper initially focuses on the classification of bionic tools, subsequently proposing five categories of bio-inspired design elements and topological models from the perspective of bioinspired cutting tools. The second discusses the applications, advantages, and cutting performance of five types of bionic tools, with an emphasis on both the biomimetic optimization of the tool body and non-tool bodies. These tools are designed by emulating the diverse biological characteristics exhibited by various organisms. Additionally, the underlying mechanisms of the five categories of bionic tools, as well as the corresponding optimization strategies, are explored. Finally, this paper summarizes research on bionic tools and analyzes the current opportunities and challenges they face. In summary, compared to traditional tools, bionic tools demonstrate superior performance in energy efficiency, friction reduction, wear resistance, lubrication, extended service life, and multifunctionality. This offers valuable insights for researchers involved in the design and development of cutting tools.

Climate change and land degradation (LD) are some of the most critical challenges for humanity. Land degradation (LD) is the focus of the United Nations (UN) Convention to Combat Desertification (UNCCD) and the UN Sustainable Development Goal (SDG 15: Life on Land). Land degradation is composed of inherent and anthropogenic LD, which are both impacted by inherent soil quality (SQ) and climate. Conventional LD analysis does not take into account inherent SQ because it is not the result of land use/land cover change (LULC), which can be tracked using remote sensing platforms. Furthermore, traditional LD analysis does not link anthropogenic LD to climate change through greenhouse gas (GHG) emissions. This study uses one of the indicators for LD for SDG 15 (15.3.1: Proportion of land that is degraded over the total land area) to demonstrate how to account for inherent SQ in anthropogenic LD with corresponding GHG emissions over time using the state of Arizona (AZ) as a case study. The inherent SQ of AZ is skewed towards low-SQ soils (Entisols: 29.3%, Aridisols: 49.4%), which, when combined with climate, define the inherent LD status. Currently, 8.6% of land in AZ has experienced anthropogenic LD primarily because of developments (urbanization) (42.8%) and agriculture (32.2%). All six soil orders have experienced varying degrees of anthropogenic LD. All land developments in AZ can be linked to damages from LD, with 4862.6 km2 developed, resulting in midpoint losses of 8.7 x 1010 kg of total soil carbon (TSC) and a midpoint social cost of carbon dioxide emissions (SC-CO2) of $14.7B (where B = billion = 109, USD). Arizona was not land degradation neutral (LDN) based on an increase (+9.6%) in the anthropogenic LD overall and an increase in developments (+29.5%) between 2001 and 2021. Considering ongoing climate change impacts in AZ, this increase in urbanization represents reverse climate change adaptation (RCCA) because of the increased population. The state of AZ has 82.0% of the total state area for nature-based solutions (NBS). However, this area is dominated by soils with inherently low SQ (e.g., Entisols, Aridisols, etc.), which complicates efforts for climate change adaptation.

The massive accumulation of waste seashells, waste sludge and waste glass not only occupies a large amount of land resources, leading to a shortage of land resources, but also causes serious soil-water-air composite pollution over a long period of time with the role of the surrounding environment, which poses a serious hazard to the ecological environment and public health. In this study, the effect patterns of waste glass powder (WGP) on the workability, mechanical properties, microstructure and carbon emission of seashell powder calcined sludge cement (SCSC) slurries prepared using waste sludge and waste seashells as supplementary cementitious materials in place of part of the cement clinker were investigated. The hydration process and microstructure of the materials were characterized by heat of hydration tests, thermogravimetry (TG-DTG), infrared Fourier transform (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that the addition of WGP improved the fluidity of SCSC slurries and reduced the shear stress of SCSC slurries without changing the flow pattern of SCSC slurries, and all the slurries conformed to the power law model. The compressive strength of SCSC slurries increased by 25.26 % with 5 % WGP addition. The CO2 emissions per cubic meter of SCSC slurries were reduced by 4.43 %, 8.81 %, 13.5 % and 18.23 % for WGP additions of 5 %, 10 %, 15 % and 20 %, respectively. These results can provide a new way for the efficient resource utilization of waste seashells, waste sludge and waste glass, and reduce the CO2 emission during the cement production process, promoting the clean production of cement.

Mining plays a central role in the global economy, making a substantial contribution to export earnings. Nevertheless, implementing sustainable mining practices that prioritise environmental responsibility during extraction remains a major challenge. In response, governments around the world have instituted policies, with the primary aim of promoting sustainable mining practices and preserving the ecosystem for future generations. Unfortunately, despite these efforts, mining operations continue to cause substantial ecological damage, marked by the transformation of landscapes and the fragmentation of ecosystems. Although regulations exist for the rehabilitation of areas degraded by mining activities, many technical aspects, particularly in relation to open-pit mining, remain poorly defined. In this article, we propose an in-depth look at a 'green' approach rooted in reclamation through revegetation-based techniques to address this critical issue. Although there are challenges such as species selection and harsh environmental conditions, revegetation and remediation techniques for reclamation offer many benefits, including soil enrichment, habitat restoration and promoting the recovery of local biodiversity. In addition, emerging technologies, such as nanomaterials, have demonstrated their effectiveness in improving soil fertility. They enable effective and long-term rehabilitation of soils disturbed by mining activities. Despite the considerable environmental impact associated with mining, the implementation of these innovative techniques promises to produce positive results and make a significant contribution to the sustainable development of the mining sector. By adopting environmentally friendly practices and constantly improving reclamation strategies, the mining industry can strive to reduce its ecological footprint and ensure a more sustainable future for itself and the surrounding ecosystems.