International Journal of Environmental Research最新文献

In the era of digitalization and under the context of "dual carbon", The green attributes of the digital economy have attracted attention, and it is worth exploring whether it can reduce carbon emissions. This paper uses inter-provincial data from 2011 to 2021 to examine whether the digital economy will play a positive role in carbon reduction. The findings are as follows: (1) There is a significant negative effect of digital economy development level on carbon emission intensity. (2) In the mediation test section, it is verified that the digital economy can reduce carbon emission intensity by optimizing the industrial structure, promoting the transformation of the energy consumption structure, improving green technology innovation, and optimizing the allocation of resources. (3) The article includes government intervention and human capital as moderating variables, and the results show that Human capital has a positive moderating effect between digital economy and carbon emission intensity, while government intervention has a negative moderating effect. (4) Digital economy has threshold effect on carbon emission intensity. (5) The influence of digital economy on carbon emission intensity shows a heterogeneous relationship between regions and factor endowments. The carbon emission reduction of digital economy in western and northeastern regions is more significant, and the abundance or scarcity of capital, labor and technology factors have different impacts on the carbon emission reduction effect of digital economy. At the same time, it further analyzes the influence of the difference of local government behavior. This paper argues that provinces and cities should strengthen the construction of digital economy, and at the same time should promote the coordinated development of digital economy among regions, which is important to achieve carbon emission reduction.

In this paper, using a direct current (DC) corona discharge with a bee-slot wire-barrel construction, the degrading efficiency of non-methane hydrocarbons (NMHCs) was examined in terms of cooking temperature, duct gas flow rate, and discharge voltage. The amount of NMHCs produced was investigated under each condition of cooking temperature of 80–120 °C and cooking oils of soybean oil, peanut oil, canola oil and lard. When soybean oil was used as the cooking fume at a cooking temperature of 200 °C, the largest concentration of NMHCs was formed. In the degradation experiment, it was found that the corona discharge treatment effect was very good, which was proportional to the discharge voltage and inversely proportional to the cooking temperature and gas flow rate, and the treatment effect was the best when the discharge voltage was 34 kV, the cooking temperature was 120 ℃ and the gas flow rate was 25 m/s, the degradation rate reached 91.40%, and the degradation could meet the national emission standards. Meanwhile, the degradation mechanism of phenanthrene, anthracene and pyrene, which are more toxic and have larger concentration in the cooking fume, was analyzed. Furthermore, response surface optimization experiments were also conducted, and the best combination of the optimized factors was 34 kV input voltage, 127.7 °C cooking temperature, and 0.011 s treatment time.

Research on urban fabric has long been a focus of interest for researchers and planners. In response to the automobile-centric design of cities, approaches such as Complete Streets have emerged to create accessible, people-centric environments by integrating various transportation modes. The study is to understand how complete street design strategies influence the connectivity and integration of the urban fabric, focusing on Haft-e-Tir Square in Tehran as a case study. Employing space syntax methodology, the current layout and a design proposal based on Complete Street strategies for the square had analysed to reveal the impact of this planning and design principle on the city’s urban fabric. The result uncovers how Complete Street hold promise in improving urban functionality and elevating the life quality. The design proposal’s interventions proved that by prioritizing pedestrians, cyclists, motorists, and transit riders, the level of safety, walkability, liveability, and environmental sustainability of the area can improve. Moreover, the findings showed a considerable reduction in the pedestrian and traffic congestion, resulting in supports for local businesses and improved urban functionalities. By contributing to the ongoing discourse on Complete Streets and its impact on shaping urban environments, this research is paving the way for future studies in this area.

Abstract

To completely replace Portland cement for mine backfilling, MSWI fly ash (FA) and solid metallurgical wastes (ground granulated blast furnace slag, steel slag and flue gas desulphurisation gypsum) were used to prepare fly ash-slag-based binder (FBB). The effect of FA content on the hydration and Pb stabilization mechanisms of the FBB was investigated. When a small amount (15%) of FA was added to FBB, hydration product formation and compressive strength were inhibited during early curing (7 d). However, the additional Ca²⁺, SO₄²⁻ and OH⁻ carried by FA could partially promote the formation of ettringite, so that the compressive strength of 28 d was comparable to that of the treatment without FA addition (32.5 MPa). When a high amount of FA (30%) was added, the hydration process was strongly inhibited throughout the entire curing period, and the leaching concentration of Zn (1052 μg/L) exceeded the limits of the GB/T 30760–2014 standard (1000 μg/L). Pb²⁺ was also found to replace Ca²⁺ in ettringite to form insoluble Pb-ettringite and Pb₂(SO₄)O precipitates, resulting in remarkable Pb stabilisation in system. Therefore, if the amount of FA incorporated is appropriate, the use of FA as an additional cementitious material for mine backfilling is an ideal method for recycling FA.

Graphical Abstract

Dujiangyan Irrigation District is the largest irrigation district in China. To understand heavy metal pollution and its potential hazards, the contents and distribution of typical heavy metals in rivers, soils and plant samples from 19 sites were studied and their ecological risks and health risks were evaluated. The results showed that the concentrations of nine heavy metals in the river water did not exceed the safe values (GB 3838-2002). They showed a trend of the highest in the middle reaches followed by the upstream and downstream areas, and the concentration in the dry season (winter) was higher than that in the wet season (summer). The average values of heavy metals in the soil were 0.3–3.08 times the background values in Chengdu. The highest average enrichment factor was Cd (7.52). The Nemerow pollution index indicated that the quality of the river water was at a clean level. However, the heavy metals in the soil at sites B1 and B3 were at a heavy pollution level. The potential ecological hazard index also showed that Cd in the soils of the study area at sites B1 and B3 was very highly hazardous and 26% of the sample area was at a highly hazardous level. The cumulative carcinogenic health risks due to total heavy metals exceeded the safety limits for both children and adults. Furthermore, the risks were higher in children than in adults. This study provides theoretical support for dealing with heavy metal pollution in the irrigation district.

Microplastics (MPs) and nanoplastics (NaPs) in coastal regions, particularly in sediments, have gained increasing attention. However, in Türkiye, research on sediment pollution by MPs and NaPs is still limited. To fill this knowledge gap, the distribution, composition, and ecological impact of MPs and NaPs were investigated for the first time in the literature over a one-year period at three sampling stations on the south coast of Istanbul. The average total particle concentration was 1364.17 ± 600.51 particles.kg⁻¹ dw sediment. Most of the MPs detected in the sediments were in the form of fibers with a size of 100–250 µm and were black and transparent. The study found that NaPs accounted for only 17%, 13.8% and 11.8% of the particles collected at stations S₁, S₂ and S₃, respectively. According to the FTIR results, polyethylene and polyethylene terephthalate were the most abundant compared to polypropylene, polyamide and other polymers. The hazard index was classified as level V with a value of 17,261. This classification emphasizes the urgent need for further comprehensive studies on the risk assessment of MPs and NaPs. Scanning electron microscopy results showed microorganisms on the particle surface, indicating the MP-associated passing-through mechanism. Moreover, energy dispersive spectroscopy detected several unexpected elements such as Nb, Sr, Mo, Bi, Ta and Rn on MP and NaP surfaces. The results indicate that MP and NaP pollution in Istanbul’s coastal sediments may pose a major risk to the environment through the leaching of inherent/adsorbed elements and therefore requires future investigation.

Energy efficiency leads to the sustainable utilization of energy resources by adopting efficient technology, which is a decisive factor for environmental sustainability. This study proposed both renewable and non-renewable energy types to measure energy efficiency and environmental sustainability in China. Furthermore, this study adds technology as an auxiliary factor for energy efficiency and sustainability to resource efficiency. Therefore, the study espouses the N-ARDL technique for asymmetric short and long run positive–negative shocks from 1985 to 2020. The asymmetric outcomes indicate that the positive and negative effects of economic growth and positive technological innovation shocks assist in mitigating carbon secretions, whereas technological innovation is not environmentally efficient during negative shocks. Simultaneously, energy efficiency is measured using both renewable and non-renewable energy factors. The positive shock in coal consumption is alarming for environmental efficiency, whereas its negative shock efficiently mitigates carbon secretions and assists environmental sustainability. However, both positive and negative shocks related to renewable energy are environmentally friendly and support environmental efficiency in China. Therefore, renewable energy is considered an energy-efficient source during asymmetric shocks, whereas non-renewable energy is only efficient during negative shocks, suggesting the sustainable utilization of coal resources. Furthermore, resource rents are inefficient during positive shocks and cause environmental deprivation, whereas they are environmentally efficient during negative shocks. These findings suggest that the Chinese government should take steps to improve environmental monitoring and enhance transparency. Further, Fintech projects under green growth and energy initiatives need further improvements to gain energy as well as resource and environmental efficiency.

• Resource rents during negative shock is considered as resource-efficient and environmentally efficient.

• Energy efficiency is measured by both renewable and non-renewable energy factors.

• The positive shock in coal consumption is alarming for environmental efficiency, while its negative shock is efficiently mitigating carbon secretions.

• Renewable energy’s is considered an energy-efficient source and both positive and negative shocks are environmental-led and support environmental efficiency in China.

• Findings illustrate that positive-negative effect of economic growth and positive technological innovation shock assist in mitigating carbon secretions.

Inadequate solid waste management (SWM) can cause environmental contamination and health risks. Minimizing the health risks from SWM practices requires the identification of linkages between potential sources of exposure, environmental transport pathways, and adverse health outcomes. A safety planning approach can represent an innovative tool for reducing such risks. In previous research, we introduced the solid waste safety plan (SWSP) concept, only focusing on the health risk ranking assessment matrix. Here, we demonstrate the application of the SWSP framework in a case study of the municipal landfill of Novi Sad, Serbia. We identify potential hazards and assessed the likelihood and severity for them, using a combination of quantitative and semi-quantitative approaches to estimate risk levels for each identified hazard. Hazards deemed high and very high risks for the community and workers include groundwater contamination from leachate, airborne contaminants from combustion and non-combustion processes, and worker injuries associated with waste combustion. Control measures for each are identified, together with a corresponding cost analysis. Adding a final top cover to the landfill and introducing a collection, transport, and treatment system for the biogas would address hazards presenting high health risks but are also among the highest costs. While we demonstrate the approach and utility of an SWSP in a research context, future work is needed to assess the use of the SWSP by local communities or SWM utilities.

Climate change has caused fundamental changes in the pattern of rainfall worldwide. Climate change can alter precipitation patterns, consequently intensifying the frequency and severity of flash floods in specific regions, including Iran. It is important for communities to be prepared for these events and to take steps to mitigate their impact. Full control or damage management of the resulted floods through structural measures is not always feasible due to economic, technological, environmental and social limitations. Therefore, often non-structural measures play an important role in reducing probable damages and casualties. The significance of advanced systems for both short- and long-term flood forecasting cannot be overstated. In this article, short-term flood prediction model is discussed using Ensemble Prediction Systems (EPSs) Machine Learning algorithms (ML) and HEC-HMS hydrological model. Also, in order to achieve high accuracy in the assessment of flood-damaged areas, remote sensing techniques have been used. The results show that the use of EPS improves the speed and accuracy of the daily prediction model (R² = 0.8). Also, with the use of Sentinel-1 radar satellite images and the simultaneous use of supervised learning algorithms, a suitable estimate of the evaded area has been made for seven selected floods in the Kan basin, which is a mountainous region in the north of Tehran, in 2015–2022 period.