Search Results (133)

Bangladesh generates approximately 3000 tons of plastic waste daily, and high mismanagement leads to substantial discharge into soils, rivers, and oceans. Limited research exists on plastic pollution along Cox’s Bazar in southeastern Bangladesh, with no studies spanning the entire coast; this study provides the first comprehensive assessment of the full coastline. This study investigates the abundance, types, and distribution of macro-, meso-, and microplastics in sediments from 23 stations covering Tourism, Active, and Less Active areas. Plastics were classified by size, shape, color, and polymer composition using stereomicroscopy and Fourier Transform Infrared Spectroscopy (FTIR), while spatial patterns of microplastic polymers were analyzed using Inverse Distance Weighted (IDW) interpolation. A total of 11,558 plastic particles were identified, with microplastics dominating (409.04 particles/m²), followed by mesoplastics (60.7 particles/m²) and macroplastics (32.8 particles/m²). Expanded polystyrene (EPS) and fragments were the most prevalent shapes, while transparent-white particles dominated in color. Polystyrene (PS), polypropylene (PP), and polyethylene (PE) comprised over 95% of polymers. IDW mapping highlighted Tourism, urban, and industrial zones as microplastic hotspots, with higher abundances in tourism areas. These findings provide a baseline for monitoring coastal plastic pollution and emphasize improved plastic management and recycling, contributing globally to understanding contamination in rapidly urbanizing, tourism-driven developing regions. Full article

With the advancement of construction development, urban renewal, and urbanization, engineering appraisal and structural reinforcement will become crucial tasks in the construction industry, thus presenting both significant challenges and long-term responsibilities. The concept of “partial strengthening and replacement composite shear walls without support roof” refers to a structural system that utilizes the existing load-bearing capacity of RC shear walls. In this method, high-performance materials are used to locally remove and replace critical load-bearing sections of the wall to be strengthened, resulting in a “composite shear wall” structure composed of both strengthened replacement areas and non-replaced sections. This study proposes the concept of composite shear walls, conducts simulation analysis and exploratory research on their bearing performance, and explores engineering applications based on engineering examples. The research conclusions include the following: Compared to only one batch of replacement reinforcement, partial strengthening and replacement in batches can significantly improve the bearing performance of composite shear walls. The use of steel-reinforced concrete for local strengthening and replacement can significantly improve the bearing performance of composite shear walls, and the magnitude of the improvement in bearing performance decreases with the increase in the initial vertical stress level of the components. The overall structural stress condition after local strengthening and replacement reinforcement is good, and its vertical and horizontal bearing capacity can meet the original design requirements (after reinforcement, the vertical bearing capacity of the overall structure increased by about 6.3% compared to the original design, and the horizontal ultimate bearing capacity is about 1.4 times larger compared to the elastic–plastic “large earthquake” effect of the original design). Compared with conventional replacement methods, the unsupported-roof local reinforcement replacement method has the advantages of using high-performance materials, reducing reinforcement engineering, minimizing resource waste, and simplifying construction procedures, and has good application prospects. Full article

The municipal solid waste recycling industry has become a rapidly growing emerging industry. Its carbon emissions account for 1/10 of the urban carbon emissions, which cannot be ignored. It is highly important for cities to achieve the goals of peak carbon and carbon neutrality and to strive for space for economic and social development. Taking Beijing as an example, using the life cycle analysis method, this paper systematically combines the historical changes in the characteristic structure of municipal solid waste. On this basis, the amount and structural characteristics of carbon emissions and their evolution are calculated, the achievements of municipal solid waste treatment in Beijing are comprehensively evaluated, and the space for further emission reduction in the future is estimated. The following conclusions are drawn: (1). Since the implementation of waste classification treatment, carbon emissions in Beijing have decreased by 22.9%. (2). Carbon emissions from plastic and paper waste from municipal solid waste have become the main source of carbon emissions from waste treatment. (3). There is still more than 2.6 × 10⁶ t of carbon emission reduction space for municipal solid waste treatment in Beijing in the future. On the basis of the calculation results, several suggestions are proposed. Full article

Plastic waste in river systems represents a major pathway of marine pollution, with rivers estimated to contribute up to 80% of the plastic entering the ocean. This study introduces a deep learning framework with preprocessing for automated detection and tracking of floating plastic waste (macroplastics) in the urban canals of the Chao Phraya River, Thailand. Unlike previous approaches that rely on site-specific retraining or model modification, our method employs a YOLO-based detection model integrated with DeepSORT (Deep Simple Online and Realtime Tracking). The model, initially trained on laboratory flume images, was adapted to real river conditions through a three-step preprocessing pipeline comprising skew correction, background removal, and object region extraction. Experiments on 2000 canal images demonstrated that preprocessing improved the mean Average Precision (mAP) from 0.74 to 0.85, with notable gains for categories such as foam and paper. Testing with a more advanced YOLO architecture further enhanced accuracy, indicating that preprocessing and model upgrades are complementary. These findings suggest that reliable detection and quantification of floating waste can be achieved without retraining. The proposed framework provides a scalable and cost-effective solution for monitoring in data-limited regions, contributing to efforts to mitigate riverine and marine plastic pollution. Future work will address the remaining limitations, as detection performance is still influenced by strong reflections, motion blur, and occlusion, occasionally resulting in missed detections. Full article

Rapid urbanization in developing regions presents a critical challenge to the provision of affordable housing. This systematic review, conducted following the PRISMA 2020 guidelines, analyzed 91 studies (2013–2024) from Scopus and Google Scholar to identify cost-effective materials and innovative techniques suitable for the developing context. Findings reveal that achieving affordability in developing regions requires a holistic approach that integrates material innovation with human capacity building. The analysis of critical success factors (CSFs) in the Rumah Unggul Sistem Panel Instant (RUSPIN) system from Indonesia and the Recycled Plastic Formwork (RPF) system from South Africa exemplifies this integration. Both systems show high potential for scalability and technological transfer using local materials and labor training. The review also highlights that materials commonly used in developed countries (e.g., autoclaved aerated concrete, expanded polystyrene, and light steel gauge framing) face adoption barriers in developing regions due to challenges related to supply chains, industry capacity, and regulatory frameworks. Conversely, locally available materials (e.g., earth, bamboo, and recycled waste) require ongoing research to enhance their availability and structural performance. Ultimately, achieving affordable housing depends on an integrated approach that combines locally sourced materials, innovative construction techniques, and the strategic application of critical success factors. Full article

The overconsumption of plastic packaging has alarming repercussions on the environment, notably through waste accumulation in public spaces and clogged drains. This study identifies factors driving plastic proliferation, analyzes their impacts, and proposes strategies for sustainable waste management. A cross-sectional design combined document review, field observations, and interviews with 156 households and 24 informants. Descriptive statistics characterized consumption patterns and service access. Impacts were assessed through litter hotspots, blocked drains, flood-prone points, and reported health risks. Households used five to six plastic bags daily, while collection coverage remained below 50%, sustaining persistent leakage. Findings reveal excessive reliance on plastics, shaped by technical, social, and institutional gaps, including weak segregation and limited pre-collection. Agoè-Nyivé 4, a fast-growing peri-urban commune within Greater Lomé, faces limited services but high consumption, making it a relevant case for rapidly growing municipalities. Yet the population often adopts counterproductive practices, hampering responsible waste management. A policy mix is outlined: expanding pre-collection and door-to-door services, integrating informal collectors, and targeted community sensitization. Without urgent interventions, plastic leakage will intensify environmental degradation, flooding, and health risks. The study recommends integrated policy measures to curb single-use dependence and foster a local circular economy. Full article

The environmental impact of companion animals has received little scientific attention compared to that of livestock, even though the global dog population is rapidly increasing, particularly in urban areas. This review addresses the overlooked contribution of dogs to environmental emissions, focusing on feces, urine, packaging waste, and other care-related by-products. The current knowledge from livestock research provides useful analogies for understanding nutrient excretion and gaseous emissions from dog feces, and data on nitrogen and phosphorus inputs highlight their potential to pollute soil and water. We also examine the role of plastic waste from food packaging, waste bags, and accessories, which can degrade into microplastics, and discuss recent developments in biodegradable materials. Evidence shows that owner choices—such as diet composition, protein sources, and product selection—directly affect the environmental pawprint of dogs. Mitigation strategies include optimizing diets to reduce nutrient excretion, applying feed additives developed for livestock, and improving waste management through composting or the use of emission-reducing amendments. In conclusion, dogs should no longer be viewed merely as individual household companions but as a population with a measurable environmental pawprint. Including dogs in emission reporting systems would provide a more accurate basis for mitigation policies and sustainable urban planning. Full article

Waste valorization in construction materials offers a promising pathway to reducing environmental burdens while promoting circular resource strategies in the built environment. This study develops a novel composite mortar formulated with sustainable materials and alternative aggregates, namely polyethylene terephthalate (PET) particles recovered from post-consumer plastic waste and bottom ash from thermal power generation. Natural pumice was incorporated to improve the lightness and the thermal insulation, with cement serving as the binder. The mix design was systematically optimized using the Taguchi method to enhance performance while minimizing carbon emissions. The resulting mortar, produced at both laboratory and small-scale commercial levels, demonstrated favorable technical properties: dry density of 1.3 g/cm³, compressive strength of 5.96 MPa, thermal conductivity of 0.27 W/(m*K), and water absorption of 16.1%. After exposure to 600 °C, it retained 60.6% of its strength and exhibited only a 10.1% mass loss. These findings suggest its suitability for non-load-bearing urban components where sustainability, thermal resistance, and durability are essential. The study contributes to global sustainability goals, particularly Sustainable Development Goal (SDG) 11, 12, and 13, by illustrating how waste valorization can foster resilient construction while reducing the environmental footprint of cities. Full article

Microplastic (MP) pollution in urban areas is a growing global concern due to its health risks and environmental effects. This study investigates the sources, spatial distribution, and health risks of MPs in road dust across industrial, capital city, and peri-urban areas of Bangladesh. Street dust samples were collected from 15 heavily congested traffic sites across Dhaka and its surrounding areas. The samples were analyzed using fluorescence microscopy and Fourier Transform Infrared (FTIR) spectroscopy to identify MP types and their morphological characteristics. We have identified six types of polymers, including Polyvinyl alcohol (PVA), Polyethylene (PE), Polypropylene (PP), Polystyrene (PS), Low-Density Polyethylene (LDPE) and High-Density Polyethylene (HDPE), with industrial areas exhibiting the highest levels of MPs followed by capital city and peri-urban zones. PP was the most prevalent MP polymer, with the highest level in industrial areas (14.1 ± 1.7 MPs/g), followed by capital city (9.6 ± 1.92 MPs/g) and peri-urban areas (7.2 ± 1.56 MPs/g). Principal Component Analysis (PCA) identified traffic emissions, industrial activities, and mismanaged plastic waste as the primary sources of MPs. Health risk evaluations indicated that children are more susceptible to MP exposure through ingestion and inhalation, with industrial areas posing the highest carcinogenic risk. The findings underscore the pressing demand for better waste management systems and stricter regulatory measures to mitigate MP pollution and safeguard public health in urban environments. Addressing these challenges is essential to reduce the growing threat of MPs and their long-term effects on ecosystems and human well-being. Full article

Microplastic pollution is an escalating environmental and public health issue. Defined as plastic particles less than 5 mm in size, microplastics have been found in oceans, rivers, food, drinking water, air, and even human tissues. While scientific research on microplastics has expanded significantly, public understanding and behavioral change remain limited. This literature scan synthesizes global findings on public awareness, perceptions, and responses to microplastics, drawing from surveys, focus groups, and online behavioral data collected by existing studies. It explores the following: (1) general knowledge and perceived environmental and health risks; (2) trust in scientific and governmental sources; (3) willingness to adopt behavioral changes; (4) attitudes toward policy and corporate responsibility. Public concern is high, especially regarding marine life and food safety, but varies across populations based on education, socioeconomic status, and media exposure. Despite growing concern, psychological distance and persistent knowledge gaps hinder meaningful action. Communication strategies such as school programs, media campaigns, and eco-labels show mixed success, while regulatory interventions like plastic bags or microbead bans are more effective when supported by clear public messaging. This literature scan highlights the need for interdisciplinary collaboration to close the knowledge–behavior–policy gap and strengthen public engagement, particularly in urban settings where consumption and waste generation are concentrated. Full article

Driven by environmental concerns and aligned with the principles of the circular economy, urban plastic waste—including packaging materials, disposable items, non-functional objects, and industrial scrap—is increasingly being collected, recycled, and marketed as a potential substitute for virgin polymers. However, the use of recycled polymers introduces uncertainties that can significantly affect both the durability and the further recyclability of the resulting products. This paper demonstrates how spectroscopic analysis in the mid-infrared (MIR) and near-infrared (NIR) regions can be applied well beyond the basic identification of the main polymeric component, typically performed during the sorting stage of recycling processes. A detailed interpretation of spectral data, based on well-established correlations between spectroscopic response and material structure, enables the classification of recycled polymers according to specific physicochemical properties, such as chemical composition, molecular architecture, and morphology. In this context, infrared spectroscopy not only provides a reliable comparison with the corresponding virgin polymer references but also proves particularly effective in assessing the homogeneity of recycled materials and the reproducibility of their properties—factors not inherently guaranteed due to the variability of input sources. As a case study, we present a robust protocol for determining the polypropylene content in recycled polyethylene samples. Full article

Waste cooking oil (WCO), a significant urban waste stream, presents untapped potential for synthesizing high-value materials. This study introduces an innovative “epoxidation-hydrolysis-blending” strategy to conveniently transform WCO into a highly flexible, photocurable elastomer suitable for 3D printing. Initially, WCO is converted into WCO-based hydroxy fatty acids (WHFA) via epoxidation and hydrolysis, yielding linear chains functionalized with multiple hydrogen-bonding sites. Subsequently, blending WHFA with hydroxyethyl acrylate (HEA) yields a novel photocurable WHFA/HEA elastomer. This elastomer exhibits excellent dimensional accuracy during vat photopolymerization 3D printing. Within the WHFA/HEA system, WHFA acts as a dual-functional modifier: its flexible alkyl chains enhance conformational freedom through plasticization while serving as dynamic hydrogen-bonding cross-linking sites that synergize with HEA chains to achieve unprecedented flexibility via reversible bond reconfiguration. Mechanical testing reveals that the optimized WHFA/HEA elastomer (mass ratio 1:3) exhibits ultra-high flexibility, with an elongation at break of 1184.66% (surpassing pure HEA by 360%). Furthermore, the elastomer demonstrates significant weldability (44.23% elongation retention after 12 h at 25 °C), physical reprocessability (7.60% elongation retention after two cycles), pressure-sensitive adhesion (glass interface adhesion toughness: 32.60 J/m²), and notable biodegradability (14.35% mass loss after 30-day soil burial). These properties indicate broad application potential in flexible electronics, biomedical scaffolds, and related fields. This research not only pioneers a low-cost route to multifunctional photocurable 3D printing materials but also provides a novel, sustainable solution for the high-value valorization of waste cooking oil. Full article

The present article examines the relationship between the changing residential net floor area of residential units in Warsaw, driven by ongoing urban growth, and the spatial requirements for household municipal waste collection. Analyzing 20 years from 2003 to 2023 across 18 districts of Warsaw, this article examines how the interplay between building morphology, demographic structure, and municipal waste generation influences the spatial and infrastructural requirements for separate collection. The study panel regression and volume simulations were applied to assess these dynamics. The results demonstrate that the number of residents per unit is the strongest predictor of waste generation, while the effect of floor area is less robust but still relevant. Waste generation per unit increased by 20% during the study period, accompanied by a sevenfold rise in plastics and a nearly eightyfold increase in biowaste, which together impose growing spatial burdens on households and collection infrastructure. The study emphasizes the significance of integrating waste infrastructure planning with housing design, considering the urban areas’ heterogeneous and evolving nature (identified at the district level). In the transition to a circular economy, the results highlight the need for locally sensitive strategies that link everyday household waste management with systemic urban sustainability goals. Full article

Post-consumer plastic waste poses increasing challenges in urban areas, where recycling heavily relies on consumer cooperation. In Japan, two recycling routes for post-consumer plastic waste from households exist, the municipal recycling route and the retailer recycling route, with the latter requiring more voluntary effort. This study aims to explore the diversity of consumers’ cooperative behaviors in Japan’s post-consumer plastic waste recycling system, with a focus on the retailer route. We conducted an online survey with 758 respondents from Sendai, Kawasaki, and Kyoto in urban Japan, using a structured questionnaire based on the knowledge–attitude–practice (KAP) framework. K-means clustering was conducted to identify behaviorally distinct consumer groups. Three clusters were revealed: Fully Engaged Consumers, Knowledge-Driven Consumers, and Passively Engaged Consumers. These groups exhibited distinct differences in cooperative recycling behaviors and socio-demographic characteristics. Our findings demonstrate the heterogeneity of consumer cooperation and underscore the importance of targeted strategies. By focusing on the retailer recycling route and consumer segmentation, this study addresses key gaps in Japan’s research on urban plastic waste. The results provide a theoretical and empirical foundation for differentiated policy-making, ultimately supporting the transition to a more sustainable and circular economy in post-consumer plastic waste recycling in urban Japan. Full article

The Anthropocene, marked by rapid and extensive environmental changes, poses distinct evolutionary pressures and opportunities for species adaptation. Insects, among the most diverse and resilient taxa, exhibit notable dietary plasticity and the ability to convert low-value biomass—such as agro-industrial and urban waste—into usable nutrients. This review explores how these traits serve as adaptive strategies, enabling insects to thrive and expand into novel, human-altered habitats. We examine the evolution of insect nutritional requirements and how alternative diets influence physiological, behavioral, and reproductive traits, ultimately enhancing resilience to anthropogenic stressors. The capacity of insects to metabolize diverse substrates not only supports their role in food security and circular economy initiatives but also provides valuable insights into detoxification pathways and metabolic flexibility in environments rich in xenobiotics. By synthesizing key studies, we highlight the pivotal role insects play in redefining ecosystem functions under human influence. This review underscores the intersection of nutritional and evolutionary biology in understanding insect success in the Anthropocene, emphasizing the importance of nutritional knowledge for both ecological research and applied insect farming systems. Full article