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Resultados 4821-4830 de 6,441
Integrated model for estimating odor emissions from civil wastewater treatment plants Texto completo
2020
Ravina, Marco | Panepinto, Deborah | Mejia Estrada, Jheyson | De Giorgio, Luca | Salizzoni, Pietro | Zanetti, Mariachiara | Meucci, Lorenza
The objective of this research project was the design and development of an integrated model for odor emission estimation in wastewater treatment plants. The SMAT’s plant, the largest wastewater treatment facility in Italy, was used as a case study. This article reports the results of the characterization phase that led to the definition and design of the proposed conceptual model for odor emission estimation. In this phase, concentrations of odor chemical tracers (VOC, H₂S, NH₃) and odor concentrations were monitored repeatedly. VOC screening with GC-MS analysis was also performed. VOC concentrations showed significant variability in space and magnitude. NH₃ and H₂S were also detected at considerable concentrations. Results were elaborated to define a spatially variable linear relationship between the sum of odor activity values (SOAV) and odor concentrations. Based on the results, a conceptual operational model was presented and discussed. The proposed system is composed by a network of continuous measurement stations, a set of algorithms for data elaboration and synchronization, and emission dispersion modeling with the application of Lagrangian atmospheric models.
Mostrar más [+] Menos [-]Red beetroot extract mitigates chlorpyrifos-induced reprotoxicity associated with oxidative stress, inflammation, and apoptosis in rats Texto completo
2020
Albasher, Gadah | Albrahim, Tarfa | Alsultan, Nouf | Alfaraj, Saleh | Alharthi, Mada S. | Kassab, Rami B. | Abdel Moneim, Ahmed E.
The goal of our investigation is to evaluate the potential protective efficacy of red beetroot extract (RBR) against testicular toxicity produced by CPF in rats. CPF exposure decreased the weight of testis and the levels of luteinizing hormone, follicle stimulating hormone and testosterone. CPF impaired also the oxidative status in favor of pro-oxidant molecules in the testicular tissue. Additionally, CPF stimulated the production of pro-inflammatory cytokines and their gene expression. Concomitantly, an apoptotic cascade has been observed upon CPF intoxication. However, RBR administration protected the testis tissue through modulating the hormonal level, inhibiting the oxidative damage, inflammation and the apoptotic responses following CPF intoxication. The obtained data recommend the use of RBR to prevent CPF-induced testicular damage via antioxidant, anti-inflammatory, and anti-apoptotic pathways.
Mostrar más [+] Menos [-]Exploring the phytoremediation potential of Cynara cardunculus: a trial on an industrial soil highly contaminated by heavy metals Texto completo
2020
Capozzi, Fiore | Sorrentino, Maria Cristina | Caporale, Antonio Giandonato | Fiorentino, Nunzio | Giordano, Simonetta | Spagnuolo, Valeria
Metal uptake capacity and growth patterns of three cardoon cultivars (Sardo, Siciliano, and Spagnolo) were investigated for phytoremediation in a metal-contaminated soil. Metal concentrations after one and two growth rounds were measured in soil and plants by ICP-MS. Potentially and promptly available metal fractions were estimated by EDTA and ammonium nitrate. Plant weight, water and nitrogen content, and life span were considered as growth parameters. After the first growth cycle, a significant accumulation of all elements was observed in roots, whereas only Cd, Cu, Fe, Pb, and Sb were significantly translocated to the shoots. After the second growth cycle, a further significant increase, especially in roots, was observed in all cultivars and for all elements considered. High percentages of the potentially available fraction were found for As, Cd, Cu, Pb, and Sb. Metal concentrations in plants were far higher than the promptly available fraction, indicating an increase of metal bioavailability during culture rounds. A severe decrease of weight and life span was observed in Sardo and Siciliano grown on polluted soil, along with an increase in N content. The cultivar Spagnolo, harmonizing a high ability of metal uptake and tolerance, proved the most efficient cultivar in metal phytoremediation.
Mostrar más [+] Menos [-]The impact of neighborhood to industrial areas on health in Uzbekistan: an ecological analysis of congenital diseases, infant mortality, and lung cancer Texto completo
2020
Aripov, Timur | Blettner, Maria | Gorbunova, Irina
After political sovereignty, Uzbekistan’s industry is growing fast. However, no investigation was performed so far, to evaluate whether an environmental risk, associated with the industry, is also increasing. Our aim was to investigate whether the distance from factories, as a surrogate measurement for environmental exposure to community, has any influence on some health outcomes in communities of Uzbekistan. For this first investigation, we analyzed prevalence of congenital diseases, infant mortality, and incidence rates of lung cancer, as examples for diseases associated with environmental factors. As crude measurement for the association, we used correlation and regression analysis with the distance to the next factory or plant as explanatory variable. A regression analysis demonstrated an association between the three outcome variables, with the strongest negative correlation (r = − 0.48) and the highest determination power (r² = 0.23) for congenital diseases’ prevalence. For infant mortality and lung cancer incidence, descriptions and analyses demonstrated lower negative correlation of them with the distance and a lower predictive power of linear models. So, closer distance of the community to specific industrial plants can be considered an indirect factor of higher prevalence of congenital diseases in those communities. Prospective research is needed to further investigate whether the association between birth defects in a neighborhood of industrial plants is causal or due to confounding factors. A policy should consider a degree of known factors distribution in an environment and perform effective prevention of congenital diseases, in close communities.
Mostrar más [+] Menos [-]Relationship between economic growth and CO2 emissions: does governance matter? Texto completo
2020
Liu, Ximei | Latif, Chalid | Latif, Zahid | Li, Nan
The environmental stress due to massive CO₂ emissions is a critical issue for scholars and policymakers. Many studies have discussed various determinants of environmental pollution both from theoretical and empirical perspectives. However, how governance influences the nexus between economic growth and CO₂ emissions is rarely studied. Hence this study investigates the relationship between economic growth, governance and CO₂ emissions within the framework of the Environmental Kuznets Curve for five high CO₂ emission countries over 1996–2017. Empirical results from the panel data estimation methods reflect that measures of governance influence emission levels differently in high CO₂ emission countries. Overall, political, economic and institutional governance enhance environmental quality. According to the results, provision of good governance needs to exercise effective measures to enhance and protect environmental quality.
Mostrar más [+] Menos [-]Spatial patterns and interspecific relationships of two dominant cushion plants at three elevations on the Kunlun Mountain, China Texto completo
2020
Zhao, Rui–ming | Zhang, Hua | An, Li–zhe
One of the most important ecological processes is the formation of interspecific relationships in relation to spatial patterns among alpine cushion plants in extreme environmental habitats. However, such relationships remain poorly understood. Here, we examined the spatial patterns of alpine cushion plants along an altitudinal gradient of environmental severity and the interspecific relationship between two cushion species (Thylacospermum caespitosum and Androsace tangulashanensis) on the eastern Kunlun Mountain of China. Our results showed that the two species were highly aggregated within a distance of 2.5–5 m at the mid (S2) altitude, whereas they were randomly distributed at the low (S1) and high (S3) altitudes. A positive spatial interaction between the two species was observed over shorter distances at the mid (S2) altitude, and the spatial patterns were related to the size of individuals of the two species. Moreover, the impact of A. tangulashanensis on T. caespitosum (RIIT. cₐₑₛₚᵢₜₒₛᵤₘ) was negative in all the study plots, and a positive impact of T. caespitosum on A. tangulashanensis (RIIA. ₜₐₙgᵤₗₐₛₕₐₙₑₙₛᵢₛ) was only observed at the mid (S2) altitude. Together, these results demonstrated that the spatial patterns of these two cushions varied with environmental severity, since the outcome of the interactions were different, to some extent, at the three altitudes. Plant size is the main factor affecting the spatial correlation and interspecific relationship between two cushions. Therefore, its potential influence should be considered when discussing interspecific relationships among cushions and their community construction at small scales in alpine ecosystems.
Mostrar más [+] Menos [-]Multi-criteria decision-making using GIS-AHP for air pollution problem in Igdir Province/Turkey Texto completo
2020
Şahin, Fatma | Kara, Mehmet Kazım | Koc, Ahmet | Sahin, Gökhan
Today, environmental problems are increasing and threatening nature and human health. Air pollution is at the top of this threat. Air, the main source of life, is indispensable for humans and living things. Therefore, air pollution causes mass results. Many air pollution studies and many solution techniques have been proposed in the literature to deal with the air pollution problem. In this study, it is called analytical hierarchy process (AHP) and geographic information systems (GIS), which is one of the multi-criteria decision making methods used in the investigation of air pollution in Iğdır city center and its four districts: Tuzluca, Iğdır Central, Karakoyunlu, and Aralik. In this study, spatial analysis of the pollutant parameters using the GIS-AHP technique was performed with the help of the data obtained from Iğdır Weather Monitoring Stations. By determining the pollutant parameters, pollution distribution maps were created, and station-based statistics were evaluated with dynamic mapping. For the first time, 15 parameters of weather and topographic features were used. Based on this result, it is obvious that Iğdır center is the worst place in the air pollution problem for GIS-AHP method. It varies for 15 parameters using GIS-AHP, compared with the review of locations on a daily basis. The aim of this study is primarily to investigate possible places of air pollution. Also, by comparing the results of two methods, GIS and AHP, more accurate results are given.
Mostrar más [+] Menos [-]Scaling up renewable energy in Africa: measuring wind energy through econometric approach Texto completo
2020
Abbas, Qaiser | Khan, Abdul Razzaq | Ahmed, Bashir | Alemzero, David Ajene | Sun, Huaping | Iram, Robina | Iqbal, Nadeem
Wind energy continues to make inroads in Africa due to falling costs and technological advancements. Most African countries are planning, exsiccating and connecting their renewable energy projects with national grid system with giving high propriety to energy security, sustainable energy consumption and low carbon emission. Many policies have been enacted by countries to promote the scaling up of wind energy and renewable energy in particular, across the globe. However, these policies have mixed effects on the deployment of wind energy. For this purpose, current study used panel data and fixed effects model for 17 African countries with wind installed generation capacity to determine the driver of wind energy development on the African continent between 2008 and 2017. The variables were grouped into three thematic areas: policy, socioeconomic, and country-specific factors. After conducting the analysis, socioeconomic variables (GDP, CO₂, energy use) and energy security variables (energy import, electricity consumption) have significant effects in determining the scaling up of wind energy in Africa. However, the policy variables of FITs, licensing during, and Tax did not have significant effects on wind energy capacity addition for the case of Africa. This study adds to the drivers of nascent wind energy deployment literature in Africa. This study suggests that set of effecitive policies are deem necessary to scale up wind energy in Africa.
Mostrar más [+] Menos [-]Upcycling spent brewery grains through the production of carbon adsorbents—application to the removal of carbamazepine from water Texto completo
2020
Sousa, Andreia F. C. | Gil, María Victoria | Calisto, Vânia
Spent brewery grains, a by-product of the brewing process, were used as precursor of biochars and activated carbons to be applied to the removal of pharmaceuticals from water. Biochars were obtained by pyrolysis of the raw materials, while activated carbons were produced by adding a previous chemical activation step. The influence of using different precursors (from distinct fermentation processes), activating agents (potassium hydroxide, sodium hydroxide, and phosphoric acid), pyrolysis temperatures, and residence times was assessed. The adsorbents were physicochemically characterized and applied to the removal of the antiepileptic carbamazepine from water. Potassium hydroxide activation produced the materials with the most promising properties and adsorptive removals, with specific surface areas up to 1120 m² g⁻¹ and maximum adsorption capacities up to 190 ± 27 mg g⁻¹ in ultrapure water. The adsorption capacity suffered a reduction of < 70% in wastewater, allowing to evaluate the impact of realistic matrices on the efficiency of the materials.
Mostrar más [+] Menos [-]Characterization of binding interaction of triclosan and trypsin Texto completo
2020
Wang, Xiaofang | Hui, Hongjie | Yu, An | Jiang, Ziyang | Yu, Hongyan | Zou, Luyi | Teng, Yue
Triclosan (TCS), a broad-spectrum antibacterial agent, exhibits a high exposure in the environment. However, the residual TCS in the environment poses a potential risk to human health. In this study, spectroscopic methods, molecular docking and animal experiment were conducted to completely understand the interaction between trypsin and TCS. The formation of the TCS-trypsin complex was spontaneously achieved through hydrogen bonds and Van der Waals forces with a binding constant (Kₐ) between 10³ and 10⁴ L mol⁻¹. In addition, the trypsin activity in fish intestine was inhibited by TCS exposure, revealing the potentially negative effects of TCS on metabolism. The results might be explained by changes in the conformation of the trypsin, inducing the content of unordered coil increasing significantly (from 36.2% to over 80%). This work provides useful information for assessing the toxicity of TCS at the molecular level.
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