Environmental Challenges最新文献

The identification of environmental impacts through Life Cycle Assessment (LCA) has become a prevalent approach in recent years. However, the utilization of software tools for LCA analysis poses challenges, particularly in terms of cost, time consumption, and complexity, especially for industries operating in emerging economies. Despite these challenges, such industries are compelled to adhere to new policies and regulations when exporting products to European countries. This paper delves into the implementation of a comprehensive approach to identify the environmental impact of the product lifecycle in the textile industry, with a specific focus on recognizing circular economic potential to mitigate environmental impacts. The methodology employed includes value chain analysis, environmental impact identification, lifecycle thinking to pinpoint sustainability hotspots, prioritization of these hotspots, and identification of potential circular economic approaches to alleviate associated impacts. The paper presents a case study applying this approach to the textile industrial sector. By scrutinizing the intricacies of circular economy frameworks, the study provides insights into the challenges and opportunities associated with transitioning towards a more sustainable and circular textile industry. The findings aim to contribute valuable knowledge to global endeavors in achieving environmentally friendly practices within the textile and apparel sector.

Incorporating technology into construction projects is highly important to achieve success. One of the critical technologies is robotics, but it faces significant barriers in terms of implementing it in the construction sector. Existing research focuses on the benefits of robotics in terms of construction management. Besides this, there is limited known study that simultaneously focuses on overcoming the barriers and their impact on success in construction projects. This research was aimed at evaluating the barriers faced in the implementation of robotics in construction and determining their impact on success. A quantitative research design was followed, starting with the identification of possible challenges from the literature, performing the pilot survey, conducting the exploratory factor analysis (EFA), and performing structural equation modeling (SEM). The results produced a structural model involving barriers and their relation to construction success with a significant positive relation value of B = 0.87. Positive implications are formulated in relation to managerial and theoretical expectations of future robotics implementation in construction projects.

Szigetköz—a large island of the Danube in Hungary—is attracting a new wave of interest in water-related regional development projects from the public and private sectors alike. The revived interest in the Szigetköz floodplain area, which has historically endured the adverse effects of large-scale water management initiatives, draws attention to the necessity for careful consideration and the active involvement of local stakeholders in the decision-making process.

In our research, we conducted various stakeholder engagement activities, including interviews, questionnaires, and workshops. These activities helped define the problems and objectives of each stakeholder group. Through collaborative consultations, we gathered over 100 proposed water related development project ideas. Additionally, to address key issues in project development and selection, we evaluated the integrative potential of each proposed project, considering the number of distinct water management issues it addressed. We also assigned an attitude score to each project, derived from the diverse objectives of various stakeholder groups, and analysed these quantities using a multiple-criteria analysis.

This paper details a novel approach to assess and rank the proposed water-related regional development project ideas based on the calculated integrative potential and attitude scores. The goal was to prioritise and further develop these proposed projects to benefit Szigetköz and its surrounding areas.

Main results of the study have shown the average project scored between 0.33–0.50 in integrative potential out of a maximum of 1.00 For positive attitude score the average was between 0.28–0.43, out of a maximum of 1.00 while for the negative attitude score the average project scored between -0.14–0.00 out of a minimum of -1.00.

The ranking of projects that was based on these scores, highlighted three types of proposed projects that need to be further developed in different ways. The top-ranked positive attitude integrative projects need cost-benefit calculations involving all ecosystem services to justify their economic sustainability. Top-ranked opposing attitude integrative projects need conflict resolution to be socially sustainable. Finally, project ideas that scored low on integrative potential need to be developed to make use of blue-green infrastructure, and circular economical advancements to foster their environmental sustainability.

The expansive soil under investigation has caused damage to lightweight structures due to its swelling and shrinkage characteristics in response to changing moisture content. The study aims to assess the impact of municipal solid waste (MSW) fly ash on the engineering properties of subgrade expansive soils and its influence on pavement structure deformation. The influence of municipal solid waste fly ash on expansive soils was evaluated using laboratory tests and finite element methods. The Abaqus software was used to investigate the effects of MSW fly ash on pavement structure deformation. The input parameters employed for this analysis were elastic modulus, Poisson ratio, load, contact area dimension, and pavement layer thickness. To mitigate this issue, MSW fly ash was used as a stabilizing agent at varying percentages (5 %, 10 %, 15 %, 20 %, 25 %, and 30 % of the dry mass of the soil sample).According to the AASHTO soil classification, the soil is classified as A-7, has a high free swell, a low soaked CBR value, and a high soaked CBR swell, and does not meet the ERA manual standard for subgrade materials. The laboratory tests shown several improvements in the engineering properties of expansive soil when MSW fly ash were mixed. These improvements included a reduction of soaked CBR swelling, free swell index, plasticity index, specific gravity, optimum moisture content. Additionally, the maximum dry density and soaked CBR values increased. Numerical analysis using Abaqus software focused on vertical deformation of the pavement structure. The results showed that as the percentage of MSW fly ash in form 0 % to 25 % of soil dry weight, the vertical deformation of the pavement structure decreased from 0.84 mm to 0.67 mm. This demonstrates that the addition of MSW fly ash reduced the deformation of expansive sub-grade soil and improved the engineering qualities of pavement structure. In conclusion, the study revealed that the use of MSW fly ash as stabilizing agent effectively reduced the deformation of expansive subgrade soil and improved the engineering qualities of pavement structure.

The Madeira River presents higher sediment flux in relation to others Amazonian rivers, contributing approximately 45 % of the sediment load to the entire Amazon Basin, that is also the region with the largest untapped hydroelectric potential. The implementation of Jirau and Santo Antonio Dams on Madeira River in Brazil created large run-of-the-river hydroelectric complex, and assessment of silting became an important issue to estimate the actual impact on sediment connectivity and on operation of the reservoir. This paper presents data of the morphology and stratigraphy of a portion of Jirau Reservoir, between the Jirau Rapids and the levees close to the Jirau Dam, in the period of February 8th to February 15th, 2022. The data were obtained by Multibeam Echo Sounder and High-Resolution Seismic Reflection. The results obtained by analysing reservoir bed morphology helped identify regions prone to siltation. The run-of-the-river Jirau Reservoir seems to have had minimal sediment retention since start of operations, as observed in seismic profiles. The suspended sediment concentration map of the study area collected for the year 2021, obtained within a parallel study based on satellite images, showed that the distribution on the surface of the reservoir correlates with the geophysical results, supporting our findings and suggesting the need for joint utilization of geophysical and remote sensing techniques.

While urban trees provides significant ecosystem services, the impact of increasing urbanization and population on their carbon sequestration potential remains relatively underexplored in interior sprawling cities, highlighting a critical research gap amid growing urban environmental challenges. Although existing studies suggest a strongly correlation between urban forest cover and carbon sequestration, this study aims to investigate how the urban demography factors influence land cover and carbon sequestration across cities with low, medium, and high population densities. Using the i-Tree Canopy tool, we sampled 18,814 random points to estimate city land cover and carbon sequestration in Arkansas, interior state of the US. Results from the principal component analysis revealed that 74% of the variation in a city's land cover among population density classes is attributed to tree and soil cover percentages. The mean annual (1.40 ± 0.08 T ha^-1) and total carbon sequestration rates (35.30 ± 5.57 T ha^-1) were significantly higher in the areas with low population density due to a higher average tree cover percentage (46%). Carbon sequestration rate was negatively associated with land cover types such as impervious surfaces like buildings (r = -0.44), roads (r = -0.28), grass cover (r = -0.46), and impervious other (r = -0.53). The log-linear model with scaled variables suggested that factors such as city's size and tree cover has positive influence urban trees' annual and total carbon sequestration, while spatial distribution and per capita income negatively affect these ecosystem befits in growing cities, regardless of population density. Travel time within city may have negative impact, while decadal population change may positively impact on carbon sequestration alongside management effort. Valuing this potential urban forest carbon sequestration for emerging carbon market could provide monetary benefits to the urban communities, city managers, and policymakers, enabling the development of effective urban forest management strategies in the context of urban climate change.

The urban climate has undergone significant changes due to rapid population growth, leading to a decline in vegetation cover and an increase in land surface temperature (LST). This study aims to assess the influence of land use land cover (LULC) changes on LST in four major urban areas in southwestern Ethiopia, namely Jimma, Bonga, Mattu and Nekemte, during the period from 2002 to 2024. To investigate the impact of LULC dynamics on LST, 30 m spatial resolution images from Landsat were utilized, including Thematic Mapper (TM) for the year 2002 and Landsat Operational Land Imager (OLI) and Thermal Infrared (TIRS) for the years 2014 and 2024. Over the past 22 years, the mean LST has increased by 2.81 °C, 2.94 °C, 3.37 °C, and 3.96 °C for Bonga, Nekemte, Mattu, and Jimma, respectively. The increase in LST can be attributed to various factors, but one of the primary reasons is linked to the rapid urbanization and decrease in forest cover. Changes in LULC triggered by rapid urbanization significantly influences LST in major cities. The results highlight the increment of impervious surface and the decline in vegetation cover as key factors contributing to the upward trend in LST. The results indicate that urban centers with less vegetation cover experienced higher LST compared to their surroundings. The results of this study indicate the necessity of effective urban planning to increase vegetation cover through urban greenery and parks to mitigate the increasing trends of LST, which can improve urban thermal comfort levels.

Lead (Pb) and cadmium (Cd) are trace elements known for their potential harm to plants. Their toxicity can lead to increased oxidative harm, disturbance in plant metabolism, and deformation in plant structure. Biochar (BC), when utilized as a soil amendment, demonstrates effectiveness in mitigating the toxicity of these heavy metals in polluted soils. To investigate the effects of BC made from sunflower residues on reducing Pb- and Cd-induced stresses in mung bean (Vigna radiata L. Wilczek), a factorial experiment was conducted based on a completely randomized design with three replications in greenhouse conditions. The factors included Pb at three levels (0, 100, and 200 mg kg^-1 as Pb (NO₃)₂), Cd at three levels (0, 10, and 20 mg kg^-1 soil as Cd (NO₃)₂), and BC at three levels (0, 1, and 3 % by weight). The results showed that Pb and Cd-induced stresses reduced all growth characteristics, such as shoot and root dry weights and the number of active root nodules. Maximum soluble sugars (0.46 mg kg^-1) and proline content (44.7 µmol g^-1) were observed in 200 mg kg^-1 of Pb and 20 mg kg^-1 of Cd treatment without BC. Also, the application of BC reduced the concentration of Pb and Cd in the shoot by 19.1 % and 13.8 %, respectively, and increased all growth traits. Therefore, the application of BC made from sunflower residues is recommended as a promising and environmentally friendly approach to improves Pb and Cd-induced stress in mung beans.

A robust and cost-effective pilot solar-powered membrane bioreactor (MBR) with downstream granular activated carbon (GAC) filter hospital wastewater treatment was developed for the Lubaga hospital in Kampala, Uganda. The MBR-GAC pilot included a 25 m² ultrafiltration (UF) module, a 100 kg GAC filter, 20 photovoltaic panels totaling 7 kW_p and a 3.55 kWh supercapacitor energy storage unit to produce non-potable and reusable water for toilet flushing, cleaning and irrigation. The pilot operated with 43% clean energy autonomy with grid and diesel generator backup for power outages of more than 1 hour. The MBR pilot produced an average flux of 10–15 L m^–2 h^–1 with 50% total organic carbon (TOC) removal. The nitrification, denitrification and filtration tanks were separated to achieve a nitrification of 80% and denitrification of 20%. The removal of typical hospital pharmaceutical residues that could not be reduced by the MBR increased to approximately 90% after the downstream GAC filter was upgraded. The removal efficiency of the GAC decreased to approximately 25% at 4,290 bed volume (BV). The significant increase of 75% in the removal efficiency of diclofenac in the MBR was attributed to the acclimation of the activated sludge. The quality of the treated wastewater from the pilot plant was sufficient for reuse by irrigation of the hospital garden, toilet flushing and cleaning. Finally, the study discussed ways to optimize the design and operation of the plant. The pilot is scalable to be replicated elsewhere and adapted in an efficient and cost-effective manner in sub-Saharan countries in Africa.

Smog has emerged as a pressing environmental issue in Lahore, Pakistan, exacerbating health problems and threatening agricultural productivity. This is comprehensively examined, the mechanisms contributing to smog formation in Lahore, highlighting the interplay of industrial emissions, vehicular pollution, crop residue burning, and atmospheric conditions. The review further explores the multifaceted impacts of smog on agriculture, highlighting decreased crop yields, soil degradation, and adverse effects on agricultural workers' health and productivity. Moreover, the health ramifications of prolonged exposure to smog are delineated, encompassing respiratory illnesses, cardiovascular diseases, and exacerbation of pre-existing conditions, particularly affecting vulnerable populations. The study consolidates current research findings and identifies knowledge gaps, emphasizing the need for interdisciplinary approaches to tackle the smog crisis effectively. Strategies for mitigating smog pollution are discussed, encompassing policy interventions, technological innovations, and public awareness campaigns. By providing a comprehensive overview of the complexities surrounding smog formation, agricultural repercussions, and public health implications, these findings underscore the urgency of adopting sustainable practices and implementing stringent regulations to combat smog pollution in Pakistan.