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New insight into monitoring degradation products during the TiO2-photocatalysis process by multivariate molecular spectroscopy 全文
2017
Stets, Sandra | do Amaral, Bianca | Bach, Larissa | Nagata, Noemi | Peralta-Zamora, Patricio G.
This study focuses on the feasibility of a spectroscopic multivariate method for monitoring the concentration of phenol and its main degradation products during heterogeneous photocatalysis. Phenolic compounds were chosen as model to evaluate the degradation process due to their toxicity and persistence in the environment and also their well-known degradation pathway. The predictive capability of the multivariate method developed by partial least squares regression (PLSR) over the spectral range of 200–350 nm was satisfactory, allowing mean predicted errors below 5.0 % in the simultaneous determination of the target compounds using six latent variables and smoothing spectra. Suitable results were reported for the simultaneous determination of hydroquinone, resorcinol, pyrocatechol, and p-benzoquinone in accordance to the chromatographic method. Characteristics such as simplicity, low cost, and fast data acquisition are remarkable in this procedure, which makes it appropriate for this type of analytical control.
显示更多 [+] 显示较少 [-]Climate change mitigation: the potential of agriculture as a renewable energy source in Nigeria 全文
2017
Elum, Z.A. | Modise, D.M. | Nhamo, G.
Energy is pivotal to the economic development of every nation. However, its production and utilization leads to undesirable carbon emissions that aggravate global warming which results in climate change. The agriculture sector is a significant user of energy. However, it has the potential to be a major contributor to Nigeria’s energy supply mix in meeting its energy deficit. More so, in the light of current and impending adverse effects of climate change, there is a need to contain GHG’s emissions. This paper focuses on bioenergy utilization as a climate change mitigation strategy and one that can, through effective waste management, enhance sustainable economic development in Nigeria. The paper employed a critical discourse analysis to examine the potential of the agricultural sector to provide biofuels from energy crops and other biomass sources. We conclude that Nigeria can reduce its GHG emissions and greatly contribute to global climate change mitigation while also alleviating its energy supply deficit if the agricultural and municipal wastes readily available in its towns and cities are converted to bioenergy. Such engagements will not only promote a clean and healthy environment but also create jobs for economic empowerment and a better standard of living for the people.
显示更多 [+] 显示较少 [-]Emissions analysis on diesel engine fuelled with cashew nut shell biodiesel and pentanol blends 全文
2017
Devarajan, Yuvarajan | Munuswamy, Dinesh babu | Nagappan, BeemKumar
The present work is intended to investigate the emission characteristics of neat cashew nut shell methyl ester (CNSME100) by adding pentanol at two different proportions and compared with the baseline diesel. CNSME100 is prepared by the conventional transesterification process. CNSME100 is chosen due to its non-edible nature. Pentanol is chosen as an additive because of its higher inbuilt oxygen content and surface to volume ratio which reduces the drawbacks of neat CNSME100. Emission characteristics were carried out in single cylinder naturally aspirated CI engine fuelled with neat cashew nut shell methyl ester (CNSME), cashew nut shell methyl ester and pentanol by 10% volume (CNSME90P10), cashew nut shell methyl ester and pentanol by 20% volume (CNSME80P20), and diesel. This work also aims to investigate the feasibility of operating an engine fuelled with neat methyl ester and alcohol blends. Experimental results showed that by blending higher alcohol to neat cashew nut shell methyl ester reduces the emissions significantly. It is also found that the emission from neat methyl ester and pentanol blends is lesser than diesel at all loads.
显示更多 [+] 显示较少 [-]Concentrations and chemical forms of heavy metals in the bulk atmospheric deposition of Beijing, China 全文
2017
Guo, Lanlan | Lyu, Yanli | Yang, Yanyan
This study aimed to investigate concentrations and mobility of selected metals (As, Cd, Cr, Co, Cu, Mn, Ni, Pb and Zn) contained in the bulk atmospheric deposition of Beijing, China, between March 2007 and February 2008, and to evaluate the metal deposition fluxes. Beijing endured heavy atmospheric deposited metal pollution with a deposition flux of 149.28 kg km⁻² year⁻¹ from nine metals studied, and a significant increasing trend was noted from metals studied during the past 23 years. High enrichment factors (EFs) of As, Zn, Pb, Cd, and Cu manifested their major anthropogenic sources. Among which, Cd and Pb require a consistent monitoring and to be strictly controlled regarding their high mobility and ecotoxicity. Furthermore, a declined metal concentration was observed in the bulk atmospheric deposition during spring, and long-transported crustal particles sourced from East Asian dust emission belt can reasonably account for this phenomenon.
显示更多 [+] 显示较少 [-]Health risk assessment of heavy metals in wheat using different water qualities: implication for human health 全文
2017
K̲h̲ān̲, Ẓafar Iqbāl | Kafīl, Aḥmad | Rehman, Sidrah | Siddique, Samra | Bashir, Humayun | Zafar, Asma | Sohail, Muhammad | Ali, Salem Alhajj | Cazzato, Eugenio | De Mastro, Giuseppe
In the recent years, the use of sewage water for irrigation has attracted the attention of arid and semi-arid countries where the availability of fresh water is poor. Despite the potential use of sewage water in crop irrigation as effective and sustainable strategy, the environmental and human risks behind this use need to be deeply investigated. In this regard, an experiment was carried out under field conditions in Nursery, University College of Agriculture Sargodha, to evaluate the possible health risks of undesirable metals in wheat grains. Wheat variety Sarang was cultivated and irrigated with different combinations of ground (GW) and sewage water (SW). The concentrations of heavy metals (Cr, Cd, Ni, and Pb) and trace elements (Cu, Zn, and Fe) in wheat grains as well as in soil were determined. Moreover, the pollution load index (PLI), accumulation factor (AF), daily intake of metals (DIM), and health risk index (HRI) were calculated. Results showed that the concentration trend of heavy metals was Pb<Cr<Cu<Ni<Cd<Zn<Fe and Cr<Cu<Pb<Cd<Ni<Fe<Zn in soil and wheat, respectively. Among metals, Cd concentration in wheat exceeded the permissible limits regardless water quality, whereas Pb concentration in grain was within the acceptable levels as suggested by World Health Organization, when 100 % of SW was used for irrigation. Similar observation was reported for Cd concentration in the soil when wheat was irrigated with 100 % SW. In comparison to soil, the edible part of wheat presented lower concentration of all studied metals, except for Zn which was much higher compared to the tested soil samples. The higher concentration of Zn was responsible for increasing the DIM of Zn where, in average, the highest value was reported, particularly in 75 % SW treatment. This was reflected also in HRI where the maximum value was reported for Zinc under the same treatment. Higher value of HRI for wheat cultivated on polluted soils suggested that appropriate management of cultivated area is necessary for food safety and thus for public health. The results are expected to create awareness among the public on the safety of consuming food products grown in particular areas.
显示更多 [+] 显示较少 [-]Monitoring PAHs in the petrochemical area of Tarragona County, Spain: comparing passive air samplers with lichen transplants 全文
2017
Domínguez-Morueco, Noelia | Augusto, Sofia | Trabalón, Laura | Pocurull, Eva | Borrull, Francesc | Schuhmacher, Marta | Domingo, José L. | Nadal, Martí
The levels of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in 8 passive air samples (PAS) and 6 lichen transplants (Ramalina fastigiata) deployed for a period of 2 months in different zones of Tarragona County (Catalonia, Spain), an area with an important number of chemical and petrochemical industries. The accumulated amount of the sum of the 16 PAHs ranged between 1363 to 7866 ng/sample in air samples. The highest concentration was found in the neighborhood of Puigdelfí (village of Perafort), in the vicinity of a big oil refinery and well under the potential influence of the petrochemical emissions. In lichen samples, the sum of the 16 PAHs ranged between 247 and 841 ng/g (dry weight), being the greatest value also observed in Puigdelfí. Data on the levels and profiles of PAHs in both passive monitoring methods were compared. A significant positive linear correlation was found between the concentrations of low molecular weight PAHs in lichens and the amounts accumulated in passive air samples (R = 0.827, P < 0.05), being especially significant the correlation of 4-ring PAHs (R = 0.941, P < 0.05). These results strongly suggest that lichens can be used to monitor gas-phase PAHs, providing data that can be quantitatively translated into equivalents for air.
显示更多 [+] 显示较少 [-]Occurrence and geographic distribution of polycyclic aromatic hydrocarbons in agricultural soils in eastern China 全文
2017
Sun, Zhe | Liu, Jing | Zhuo, Shaojie | Chen, Yuanchen | Zhang, Yanyan | Shen, Huizhong | Yun, Xiao | Shen, Guofeng | Liu, Weiping | Zeng, E. Y. (Eddy Y.) | Tao, Shu
Polycyclic aromatic hydrocarbons (PAHs) in agricultural soils, eastern China, were studied through a collection of surface samples at 109 sites. The study covered US EPA priority pollutants but also several non-priority isomers including some dibenzopyrenes which are expected to have higher toxic potentials. The total PAH concentrations varied extensively from 8.8 to 3880 μg/kg, with a geometric mean of 158 μg/kg. There were significant differences in both the concentrations and composition profiles between the south and the north regions. The overall geographical distribution pattern was strongly influenced by both the per capita gross domestic product and soil organic carbon (SOC) content. The former is an indicator of anthropogenic emissions while soil SOC content is associated with the accumulative capacities of the soils. The sequestration mechanism is an important process controlling fates of PAHs in agricultural soil.
显示更多 [+] 显示较少 [-]A consumption value-gap analysis for sustainable consumption 全文
2017
Biswas, Aindrila
Recent studies on consumption behavior have depicted environmental apprehension resulting from across wide consumer segments. However, this has not been widely reflected upon the growth in the market shares for green or environment-friendly products mostly because gaps exist between consumers’ expectations and perceptions for those products. Previous studies have highlighted the impact of perceived value on potential demand, consumer satisfaction and behavioral intentions. The necessity to understand the effects of gaps in expected and perceived values on consumers’ behavioral intention and potential demand for green products cannot be undermined as it shapes the consumers’ inclination to repeated purchase and consumption and thus foster potential market demand. Pertaining to this reason, the study aims to adopt a consumption value-gap model based on the theory of consumption values to assess their impact on sustainable consumption behavior and market demand of green products. Consumption value refers to the level of fulfillment of consumer needs by assessment of net utility derived after effective comparison between the benefits (financial or emotional) and the gives (money, time, or energy). The larger the gaps the higher will be the adversarial impact on behavioral intentions. A structural equation modeling was applied to assess data collected through questionnaire survey. The results indicate that functional value-gap and environmental value-gap has the most adversarial impact on sustainable consumption behavior and market demand for green products.
显示更多 [+] 显示较少 [-]Cytotoxic effects of seven Tunisian hospital wastewaters on the proliferation of human breast cancer cell line MDA-231: correlation with their chemical characterization 全文
2017
Nasri, Emna | Machreki, Monia | Beltifa, Asma | Aroui, Sonia | Ghorbel, Asma | Saad, Amina | Feriani, Anouar | Borgi, Mohamed Ali | Ghazouani, Lakhdar | Sire, Olivier | Balcázar, José Luis | Mansour, Hedi Ben
Hospital wastewaters contain large amounts of pharmaceutical residues, which may eventually be discharged into the aquatic environment through wastewater treatment plants, raising the question of their impact on human and environmental health. This has prompted the launch of several monitoring studies into the most commonly administered compounds in urban wastewater. The aim of this study was, therefore, to explore the cytotoxic potential of wastewaters samples collected from seven hospitals in Tunisia. The physicochemical analyses showed a large fluctuation of certain parameters in the collected samples, such as chemical oxygen demand (ranged from 860 to 1720 mg L⁻¹), biochemical oxygen demand (ranged from 385 to 747 mg L⁻¹), total organic carbon (ranged from 256 to 562 g L⁻¹), total suspended solids (ranged from 905 to 1450 mg L⁻¹), conductivity (ranged from 3.31 to 7.14 μsm/cm), and turbidity (ranged from 100 to 480 NTU). The analysis using inductively coupled plasma mass spectrometry (ICP-MS) also showed that hospital wastewater contains high concentrations of Hg (ranged from 0.0024 to 0.019 mg L⁻¹). This could be explained by the variation of the activity and the services in certain hospitals compared to others. All hospital wastewater samples induced the proliferation of human breast cancer cell line MDA-231, even at low concentrations (20 μL/assay). Moreover, the maximum induction reached at the concentration of 60 μL/assay in wastewater samples from hospitals located in Monastir, Sidi Bouzid, Mahdia, and Sfax with percentages of induction up to 42.33, 14, 7.61, and 5.42%, respectively. These observations could be due to the presence of endocrine disrupting compounds (EDCs) in these wastewaters. Given this, our results evidenced the potential risk of these hospital effluents to environmental and public health.
显示更多 [+] 显示较少 [-]Dental enamel as biomarker for environmental contaminants in relevant industrialized estuary areas in São Paulo, Brazil 全文
2017
de Oliveira, Vera Lucia Ferreira | Gerlach, Raquel Fernanda | Martins, Lourdes Conceição | de Souza Guerra, Carolina | Frazão, Paulo | Braga, Alfésio Luis Ferreira | Pereira, Luiz Alberto Amador
Heavy metal contamination is a long-standing and very well-known public health problem, and its exposure can cause damage to several organs of human body, especially on the central nervous system of young children and teenagers. The aim of this article is to evaluate lead, cadmium, and manganese contamination in 125 children from 6 to 13 years old living in contaminated areas during the period from 2006 to 2009 (São Vicente, Cubatão Downtown, Bertioga and Cubatão Pilões/Água Fria). This estuary area is the most important example of environmental degradation by chemicals from industrial sources. This is a cross-sectional study through clinical examinations and dental enamel tests. All mothers from these children lived in the area since before the pregnancy. Lead, cadmium, and manganese levels (μg/g) were measured on dental enamel samples through graphite furnace atomic absorption spectrometry, searching for the occurrence of heavy metals. The mean lead concentrations were 139.48 μg/g in Cubatão Pilões/Água Fria, 170.45 μg/g in Cubatão Downtown, 213.52 μg/g in São Vicente, and 151.89 μg/g in Bertioga. The mean cadmium concentrations were 10.83 μg/g in Cubatão Pilões/Água Fria, 12.58 μg/g in Cubatão Downtown, 10.92 μg/g in São Vicente, and 14.57 μg/g in Bertioga. The mean manganese concentrations were 23.49 μg/g in Cubatão Pilões/Água Fria, 30.90 μg/g in Cubatão Downtown, 41.46 μg/g in São Vicente, and 42.00 μg/g in Bertioga. Dental surface enamel may be used as an efficient biomarker of past environmental exposure to lead, manganese, and cadmium which are associated to well-known sources of heavy metal contamination. The results suggest that the evaluated children were exposed to sources of lead, cadmium, and manganese since before their conceptions. Although Bertioga initially was chosen as a control area of this study, it was also was verified to have heavy metal contamination on examined children.
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