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Assessing and building climate change resilience of farming systems in Tunisian semi-arid areas Texte intégral
2021
Ben Nasr, Jamel | Chaar, Hatem | Bouchiba, Fadoua | Zaibet, Lokman
The agricultural sector plays a strategic role in the Tunisian economy, particularly in rural areas. Resilience and adaptation to climate change are the main challenges facing this sector. This paper aims to analyze climate change resilience of agricultural production systems in Tunisian semi-arid areas and to propose options for policy interventions. A path Structural Equation Model (SEM) was used to predict the resilience of these systems using the partial least squares method (PLS). Results show that farming systems in Tunisian semi-arid areas remain threatened against negative impact of climate change since 80% of farms in the sample have shown low resilience levels. The most important determinants of agricultural systems’ resilience are farmers’ income and access to food, adaptive capacity, and access to productive and non-productive assets. Results indicate also that integrated systems, income diversification, along with cooperation and collective action are the key options to enhance resilience of rural households and farming systems. It is recommended to raise awareness of stakeholders and decision-makers about climate change challenges and to develop integrated approaches to better engaging with local stakeholders and institutions in adaptation programs and strategies development.
Afficher plus [+] Moins [-]Extracting cadmium in the presence of salt: a study on three poplar clones under controlled conditions Texte intégral
2021
Capuana, Maurizio | Bianchi, Elisabetta | Cencetti, Gabriele | Colzi, Ilaria | Gonnelli, Cristina
This study aimed at determining the cadmium phytoextraction potential of three Populus alba L. clones cultivated in the presence of increasing sodium chloride concentrations. Plantlets of a commercial and two autochthonous poplar clones were grown in perlite with nutrient solution enriched in CdSO₄ (50 and 100 μM) and NaCl (25 and 50 mM), administered either alone or in combination. The three clones showed significant variation not only in cadmium and salt tolerance, accumulation and content, but also in the effect of the interaction between the two elements on these parameters. The toxic effect of Cd and salt excess on plants was mutually exacerbated by the presence of both. Even though the outcome of the joint treatment was always a decrease in shoot Cd or Na accumulation, the three clones showed variation in the extent of such reduction. Evaluating the total element content per plant shoot, the fast-growing commercial clone displayed the highest phytoextraction potential for Cd and Na, either alone or in mixture. Our results demonstrated for the first time that the Cd response in presence of salt can vary in the different clones.
Afficher plus [+] Moins [-]Interaction between meteorological parameters and COVID-19: an ecological study on 406 authorities of the UK Texte intégral
2021
Sarmadi, Mohammad | Rahimi, Sajjad | Evensen, Darrick | Kazemi Moghaddam, Vahid
Understanding the factors affecting COVID-19 transmission is critical in assessing and mitigating the spread of the pandemic. This study investigated the transmissibility and death distribution of COVID-19 and its association with meteorological parameters to study the propagation pattern of COVID-19 in UK regions. We used the reported case and death per capita rate (as of November 13, 2020; before mass vaccination) and long-term meteorological data (temperature, humidity, precipitation, wind speed, and visibility) in 406 UK local authority levels based on publicity available secondary data. We performed correlation and regression analysis between COVID-19 variables and meteorological parameters to find the association between COVID-19 and independent variables. Student’s T and Mann–Whitney’s tests were used to analyze data. The correlation and regression analyses revealed that temperature, dew point, wind speed, and humidity were the most important factors associated with spread and death of COVID-19 (P <0.05). COVID-19 cases negatively correlated with humidity in areas with high population density, but the inverse in low population density areas. Wind speeds in low visibility areas, which are considered polluted air, may increase the spread of disease (r=0.42, P <0.05) and decrease the spread in high visibility areas (r=−0.16, P <0.05). Among low (T <10°C) and high (T >10°C) temperature areas, the average incidence rates were 2056.86 (95% confidence interval (CI): 1909.49–2204.23) and 1446.76 (95% CI: 1296.71–1596.81). Also, COVID-19 death per capita rates were 81.55 (95% CI: 77.40–85.70) and 69.78 (95% CI: 64.39–75.16) respectively. According to the comprehensive analysis, the spread of disease will be suppressed as the weather warms and humidity and wind speed decrease. Different environmental conditions can increase or decrease spread of the disease due to affecting spread of disease vectors and by altering people’s behavior.
Afficher plus [+] Moins [-]The combined chemical and mechanical modifications of cigarette: a novel methodology to reduce harmful effects Texte intégral
2021
Kollati, Prudhvi Ravikumar | Mohapatra, Soumya Sanjeeb
Without hindering the taste, making a cigarette less harmful by reducing the percentage of toxic and carcinogenic compounds in the smoke of the cigarette is a challenging task for the current generation of researchers. In the current work, by implementing mechanical, chemical and combined modification techniques, the above stated is tried to mitigate. In addition to the above, the optimum suction pressure, burning time and the number of puffing are also determined. Mechanical modification technique considers filter to cigarette ratio and filter design as the controlling parameters. The mathematical calculation reveals that puffing should stop when the cigarette length reaches 0.15 times of its original length. Furthermore, it is also identified that the concentrations of suspended solids and droplets in the smoke decrease significantly (separation efficiency = 56.81%) if the cigarette to filter ratio is maintained at 2.32. In case of chemical modification, by using various types of adsorbents such as charcoal and Zeolite 13X, the harmful effects are further reduced. These processes depict significant reduction in harmful effect (separation efficiency up to 62.1%) by showing the decrement in the suspended solids and droplets in the smoke due to the adsorption on the active sites of adsorbents. In case of combined modification, the achieved separation efficiency is 66.51%. For the experimentation, an experimental setup fitted with artificial lungs was used.
Afficher plus [+] Moins [-]Emergency hospital admissions for cardiovascular diseases attributed to air pollution in Tehran during 2016-2019 Texte intégral
2021
Sepandi, Mojtaba | Akbari, Hamed | Naseri, Mohammad Hassan | Alimohamadi, Yousef
The burden of five main air pollutants, including CO, O3, NO2, SO2, and PM2.5, on the emergency department visits (EDVs) during January 2016–December 2019 due to all cardiovascular diseases was assessed in Tehran by using a time-series model. The pollutants data were collected from Iran Department of Environment including 10 air pollution monitoring stations for the period of our study. Cumulative relative risk and attributable number/fraction were calculated for each pollutants by a Quasi-Poisson time-series regression and distributed lag non-linear model (DLNM). The maximum lag was set to 14 days because harvesting effect is more likely happened during few days. We used percentile 25 as reference value in order to calculate cumulative relative risk and attributable fraction. About 69,000 patients with cardiovascular symptoms have been admitted into the hospital during 4 years. The cumulative relative risk during the 14 days was 1.13 (1.01, 1.26), 1.15 (1.02, 1.29), and 1.08 (1.01, 1.18) for CO, NO2, and PM2.5, respectively. The numbers attributed to all values of CO were more than others; about 3800 EDVs were significantly attributed to CO, of which over 3000 were significantly attributed to high values of the pollutant. Low values of all pollutants were, not surprisingly, responsible for low number of EDVs. PM2.5, CO, and NO2 were responsible to considerable attributable number of EDVs. Our study emphasizes the need for local authorities to establish a program to reduce the air pollution in Tehran.
Afficher plus [+] Moins [-]A methodology for the technical-economic analysis of municipal solid waste systems based on social cost-benefit analysis with a valuation of externalities Texte intégral
2021
Medina-Mijangos, Rubí | De Andrés, Andrés | Guerrero-Garcia-Rojas, Hilda | Seguí-Amórtegui, Luis
Countries face a serious problem due to the generation and management of higher volumes of waste. Large-scale production of waste has promoted the establishment of various operations (collection, transport, treatment and disposal) for its management. When a MSW management system is implemented, it can generate different impacts or consequences (internal or external impacts). Generally, external impacts (social and environmental impacts) are not reflected in MSW economic analysis or taken into consideration in decision-making processes in regard to MSW management options. For this reason, the objective of this paper is present a methodology with which is viable to conduct the technical-economic analysis of municipal solid waste management projects based on social cost-benefit analysis (sCBA) as it considers internal and external impacts. Its main objectives are to determine the total benefits (the difference between revenues and costs) generated by a project and to reduce uncertainty and risk of investing in particular MSW management system. Finally, a case study was carried out to verify the validity of the methodology through analysis and valuation of different impacts of a light packaging waste and bulky waste facility. Through the application of the methodology, it has been possible to visualize that this facility is viable operationally (BP = 42.94 €/ton) as economically (BT = 87.73 €/ton).
Afficher plus [+] Moins [-]Electrochemical degradation of psychotropic pharmaceutical compounds from municipal wastewater and neurotoxicity evaluations Texte intégral
2021
Bosio, Morgana | de Souza-Chaves, Bianca Miguel | Saggioro, Enrico Mendes | Bassin, João Paulo | Dezotti, Márcia W. C. | Quinta-Ferreira, Maria Emília | Quinta-Ferreira, Rosa M.
Contaminants of emerging concern (CECs) are released daily into surface water, and their recalcitrant properties often require tertiary treatment. Electrochemical oxidation (EO) is often used as an alternative way to eliminate these compounds from water, although the literature barely addresses the neurotoxic effects of residual by-products. Therefore, this study investigated the performance of EO in the removal of five CECs (alprazolam, clonazepam, diazepam, lorazepam, and carbamazepine) and performed neurotoxicity evaluations of residual EO by-products in Wistar rat brain hippocampal slices. Platinum-coated titanium (Ti/Pt) and boron-doped diamond (BDD) electrodes were studied as anodes. Different current densities (13–75 A m⁻²), pH values (3–10), electrolyte dosages (NaCl), and matrix effects were assessed using municipal wastewater (MWW). The drugs were successfully degraded after 5 min of reaction for both the Ti/Pt and BDD electrodes when a current density of 75 A m⁻² was applied. For Ti/Pt and BDD, neutral and acidic pH demonstrated better CEC removal performance, respectively. Compound degradation using MWW achieved 40% removal after 120 min for Ti/Pt and ranged between 33 and 52% for the BDD anode. For Ti/Pt, neurotoxicity studies using MWW indicated a decrease in reactive oxygen species (ROS) signals. However, when an artificial cerebrospinal fluid (ACSF) medium was reapplied, the signal recovered and increased to a value above the baseline, indicating that cells recovered part of their normal activity but remained in a different condition. For the BDD anode, the treated MWW did not cause significant ROS production variations, suggesting that he EO was effective in eliminating the toxicity of the treated solution.
Afficher plus [+] Moins [-]Air quality in cabin environment of different passenger cars: effect of car usage, fuel type and ventilation/infiltration conditions Texte intégral
2021
Tolis, Evangelos I. | Karanotas, Tilemachos | Svolakis, Grigoris | Panaras, George | Bartzis, John G.
Despite that commuters spend only 5.5% of their time in cabin vehicles, their exposure to harmful air pollutants, originated from the vehicle itself, and traffic emission is considered significant. In this study, two passenger cars with different type of fuels were investigated in terms of air quality and thermal comfort of their cabin. Investigation was performed in the city of Kozani, Northern Greece. Moreover, air samples near the exhausts were taken, in order to compare concentration of compounds found indoors. Twelve volatile organic compounds and CO₂ were measured inside the cabin when the cars were stopped, when idle and when they were cruising in medium and heavy traffic roads, under various ventilated conditions. Thermal comfort was investigated while driving the cars through the city traffic. Results showed that the air around the diesel exhaust is less affected by emissions from the engine compared to LPG fuel. This is reflected to the TVOC measured into the cabin. Results also revealed that the air quality of a diesel fuel moving car with open windows is only affected by the traffic emissions from neighbouring vehicles, while for the car with LPG fuel, the self-pollution from its own exhaust might contribute together with the outdoor air.
Afficher plus [+] Moins [-]Research progress in bioremediation of petroleum pollution Texte intégral
2021
Yang, Yong | Zhang, Zhan-Wei | Liu, Rui-Xia | Ju, Hai-Yan | Bian, Xue-Ke | Zhang, Wan-Ze | Zhang, Chuan-Bo | Yang, Ting | Guo, Bing | Xiao, Chen-Lei | Bai, He | Lu, Wen-Yu
With the enhancement of environmental protection awareness, research on the bioremediation of petroleum hydrocarbon environmental pollution has intensified. Bioremediation has received more attention due to its high efficiency, environmentally friendly by-products, and low cost compared with the commonly used physical and chemical restoration methods. In recent years, bacterium engineered by systems biology strategies have achieved biodegrading of many types of petroleum pollutants. Those successful cases show that systems biology has great potential in strengthening petroleum pollutant degradation bacterium and accelerating bioremediation. Systems biology represented by metabolic engineering, enzyme engineering, omics technology, etc., developed rapidly in the twentieth century. Optimizing the metabolic network of petroleum hydrocarbon degrading bacterium could achieve more concise and precise bioremediation by metabolic engineering strategies; biocatalysts with more stable and excellent catalytic activity could accelerate the process of biodegradation by enzyme engineering; omics technology not only could provide more optional components for constructions of engineered bacterium, but also could obtain the structure and composition of the microbial community in polluted environments. Comprehensive microbial community information lays a certain theoretical foundation for the construction of artificial mixed microbial communities for bioremediation of petroleum pollution. This article reviews the application of systems biology in the enforce of petroleum hydrocarbon degradation bacteria and the construction of a hybrid-microbial degradation system. Then the challenges encountered in the process and the application prospects of bioremediation are discussed. Finally, we provide certain guidance for the bioremediation of petroleum hydrocarbon-polluted environment.
Afficher plus [+] Moins [-]Estimation of microplastics in sediments at the southernmost coast of India (Kanyakumari) Texte intégral
2021
Sundar, Sajimol | Chokkalingam, Lakshumanan | Roy, Priyadarsi D. | Usha, Tune
Increasing urbanization and anthropogenic activities of the last couple of decades have left significant amounts of plastic debris in both coastal and marine ecosystems. In this study, we estimated the abundance of microplastics (particle size < 5 mm) in the beach sediments of southernmost India at Kanyakumari by collecting sediments from harbors, coastal fishing villages/residential beaches, tourist beaches, and undisturbed coastal areas along the Indian Ocean. We recovered 343 particles (67% fiber and 33% fragment) from eight different stations by evaluating 50 g dry sediments (d.s.) from each location. All of them were secondary microplastics and most of them (i.e., 331 out of 343 particles) were transparent. Tourist beaches had the highest concentration (150 particles/50 g d.s.), followed by the harbors (99 particles/50 g d.s.). The undisturbed beach contained the least amount of microplastics, representing only 4.3% of the total recovered particles. Our study relates the abundance of microplastics to different degrees of anthropogenic activities. Further research, however, is required to identify the mechanism that influenced their transport and deposition in the coastal sediments as well as to evaluate the possible interaction between microplastic particles and marine ecosystems.
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