细化搜索
结果 2331-2340 的 4,308
Phytoremediation of fluoride with garden ornamentals Nerium oleander, Portulaca oleracea, and Pogonatherum crinitum 全文
2017
Khandare, Rahul V. | Desai, Shaileshkumar B. | Bhujbal, Sourabh S. | Watharkar, Anuprita D. | Biradar, Shivtej P. | Pawar, Pankaj K. | Govindwar, Sanjay P.
Nursery grown plants of Nerium oleander, Pogonatherum crinitum, and Portulaca oleracea were observed to remove fluoride up to 92, 80, and 73%, respectively, from NaF solution at the concentration of 10 mg L⁻¹ within 15 days. Concentration range of 10–50 mg L⁻¹ of fluoride revealed a constant decrease of removal from 92 to 51% within 15 days by N. oleander, while the biomass (one to five plants) showed enhancement in removal from 74 to 98% in 10 days. Translocation and bioaccumulation factors calculated after fluoride contents in roots and leaves of N. oleander, P. crinitum, and P. oleracea were 1.85, 1.19, and 1.43, and 9.8, 3.6, and 2.2, respectively. P . oleracea, P. crinitum, and N. oleander showed reductions in chlorophyll contents by 40, 57 and 25 and 8%, carbohydrates by 50, 44, and 16%, and proteins by 38, 53, and 15%, respectively. Activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) in the roots of P. oleracea, P. crinitum, and N. oleander were observed to be induced by 400, 383, and 500%; 80, 105, and 424%; and 153, 77, and 71%, respectively, while the leaves showed induction in SOD, CAT, and GPX activities by 550, 315, and 165%; 196, 227, and 243%; and 280, 242, and 184%, respectively. Results endorsed the superiority of N. oleander for fluoride removal over other plant species.
显示更多 [+] 显示较少 [-]Evaluating the efficiency of nuclear energy policies: an empirical examination for 26 countries 全文
2017
Gözgor, Giray | Demir, Ender
The decarbonization of the global economy is an urgent concern. As a potential solution, it can be important to understand the efficiency of nuclear energy policies. For this purpose, the paper analyzes whether there is a unit root in nuclear energy consumption in 26 countries and it uses the unit root tests with two endogenous (unknown) structural breaks. The paper finds that nuclear energy consumption is stationary around a level and the time trend in 25 of 26 countries and nuclear energy consumption contains a unit root only in France. The paper also discusses the potential implications of the findings.
显示更多 [+] 显示较少 [-]Alterations in soil microbial communities caused by treatments with penicillin or neomycin 全文
2017
Zhang, Qichun | Kang, Ouyang | Jabeen, Salma | Dick, Warren A.
Antibiotic residues in soils can lead to serious health risk and ecological hazards. In this study, the effects of penicillin and neomycin, two antibiotics widely used in animal production, were investigated on soil bacterial communities. Changes in the community structure were monitored using three 16S ribosomal DNA (rDNA) polymerase chain reaction-based approaches, including denaturing gradient gel electrophoresis (DGGE), amplified rDNA restriction analysis (ARDRA), and terminal-restriction fragment length polymorphism (T-RFLP) analysis. The prominent DGGE bands were excised from gels and sequenced, and the data indicated the prevalence of Gammaproteobacteria in the soils. The total soil bacterial community, including uncultured bacteria, exhibited a higher diversity than that of cultured bacteria. Some microbial strains were capable of surviving and even subsisting on penicillin or neomycin. We also observed toxic effects of the antibiotics on the indigenous soil bacterial communities since some genotypes disappeared after the treatments (e.g., Pseudomonas sp., Stenotrophomonas sp., Salinimonas, and uncultured Acinetobacter sp.). The implications of these findings are that the functions of soil bacterial communities may be negatively affected if key microbial community members are lost.
显示更多 [+] 显示较少 [-]Hexabromocyclododecane diastereomers in fish and suspended particulate matter from selected European waters—trend monitoring and environmental quality standard compliance 全文
2017
Rüdel, Heinz | Müller, Josef | Nowak, Jens | Ricking, Mathias | Klein, Roland | Kotthoff, Matthias
The brominated flame retardant hexabromocyclododecane (HBCD) was monitored in fish and sediment (from one lake) or suspended particulate matter (SPM; from five rivers) at European freshwater sites to study the effects of reduction measures implemented by HBCD producers and users in recent years. Bream (Abramis brama) were sampled annually between 2007 and 2013 in the rivers Götaälv/SE, Rhône/FR, Western Scheldt/NL, Mersey/UK, and Tees/UK and in Lake Belau/DE. Sediment/SPM was taken every second year between 2008 and 2014. HBCD was analyzed by LC/MS/MS allowing the determination of the alpha-, beta-, and gamma-diastereomers. For most sites, a decrease in ∑HBCD was observed in fish (e.g., in the Rhône and Western Scheldt by about 80 and 60%, respectively, with significantly decreasing trends, p < 0.01). In the Rhône, HBCD also decreased in SPM. At the sampling site in the Tees which was impacted by a former HBCD point source, fish HBCD levels decreased only after a major flood event in 2013. While fish data indicate a decline in environmental HBCD concentrations at most sites with diffuse emissions, SPM data were less conclusive. The European environmental quality standard for HBCD in fish of 167 μg kg⁻¹ wet weight was met by all fish samples in 2013.
显示更多 [+] 显示较少 [-]Effectiveness of waste prevention program in primary students’ schools 全文
2017
Zorpas, Antonis A. | Voukkali, Irene | Loizia, Pantelitsa
Even though reducing waste is at the top of the waste hierarchy, no real decoupling between waste generation and consumption has been demonstrated. Several waste directives had been published from EU, but they have only brought minor changes within the key objective of reducing waste generation. Most efforts have been targeted towards greater amounts of recycling and better management of waste disposal. While these are necessary and socially beneficial goals, they are not adequate for the achievement of long-term sustainability goals. The purpose of this study is to understand students’ knowledge, attitudes and behavioural changes in relation to the water plastic bottle of 500 ml. Understanding waste prevention behaviour (WPB) could enable schools’ principals, local authorities and committees as well as decision makers to design and implement more effective policies for reducing the amount of specific waste streams that is generated. Students in a daily base bring their own water containers of 500 ml or buy water from the school as they do not feel safe to use other sources of water. Nine hundred ninety-eight refilling stainless steel water refilling bottles (SSWRB–of 600 ml) were shared to the students in four primary schools. The results indicated that the students are presented with different behaviours from class to class for many reasons; most of them are related with what their parents believe, and how themselves or the synergies between them reacts and affected.
显示更多 [+] 显示较少 [-]Tools based on multivariate statistical analysis for classification of soil and groundwater in Apulian agricultural sites 全文
2017
Ielpo, Pierina | Leardi, R. (Riccardo) | Pappagallo, Giuseppe | Uricchio, Vito Felice
In this paper, the results obtained from multivariate statistical techniques such as PCA (Principal component analysis) and LDA (Linear discriminant analysis) applied to a wide soil data set are presented. The results have been compared with those obtained on a groundwater data set, whose samples were collected together with soil ones, within the project “Improvement of the Regional Agro-meteorological Monitoring Network (2004–2007)”. LDA, applied to soil data, has allowed to distinguish the geographical origin of the sample from either one of the two macroaeras: Bari and Foggia provinces vs Brindisi, Lecce e Taranto provinces, with a percentage of correct prediction in cross validation of 87%. In the case of the groundwater data set, the best classification was obtained when the samples were grouped into three macroareas: Foggia province, Bari province and Brindisi, Lecce and Taranto provinces, by reaching a percentage of correct predictions in cross validation of 84%. The obtained information can be very useful in supporting soil and water resource management, such as the reduction of water consumption and the reduction of energy and chemical (nutrients and pesticides) inputs in agriculture.
显示更多 [+] 显示较少 [-]Does static electric field from ultra-high voltage direct-current transmission lines affect male reproductive capacity? Evidence from a laboratory study on male mice 全文
2017
Wu, Sixia | Di, Guoqing | Li, Zhengguang
With the development of ultra-high-voltage direct-current (UHVDC) transmission technology and increase in transmission voltage, the issue of environmental static electric field (SEF) pollution is standing out and its possible health effects have caused much public attention. In this study, the effects of chronic exposure to SEF on reproductive capacity of male mice were investigated. Twenty Institute of Cancer Research (ICR) mice were exposed to SEF (56.3 ± 1.4 kV/m, 49 days) generated by a high-voltage device. Several biological end points related to spermatogenesis and testicular function were evaluated, including reproductive organ coefficients, sperm motility and morphology, serum testosterone level, and testicular histology. No significant differences were found between the SEF-exposed and sham-exposed groups at the end of the exposure period. However, further observation through transmission electron microscopy revealed cristae losses in mitochondria of spermatogenic cells after SEF exposure. Nevertheless, the mitochondria injury did not affect sperm motility, which might be explained from the perspective of energy supply. That is, most of the energy required for sperm movement is generated by glycolysis which occurs in the cytoplasm rather than oxidative phosphorylation which occurs in mitochondria. In conclusion, this study indicates that exposure to SEF (56.3 ± 1.4 kV/m, 49 days) has limited effects on male reproductive capacity.
显示更多 [+] 显示较少 [-]Sorption and desorption of silver ions by bentonite clays 全文
2017
Constantino, Leonel Vinicius | Quirino, Juliana Nunes | Monteiro, Alessandra Maffei | Abrão, Taufik | Parreira, Paulo Sérgio | Urbano, Alexandre | Santos, María Josefa
Anthropogenic activities have increased the concentration of metal species in the environment. The toxicity of silver ions to aquatic and terrestrial organisms has required monitoring by analytical methods, besides actions to promote its control as pollutant. Sorption and desorption processes are directly related to the mobility and availability of metal ions in the environment. In this context, clay minerals can be used for pre-concentration, removal and recovery of silver ions from aqueous solution. Herein, two bentonite clays (BaVC-1 and SWy-2) were characterised and applied to investigate the sorption and desorption of silver ions. Isotherms were fitted to the dual-mode Langmuir-Freundlich model to qualify and quantify sorption sites and evaluate the mobilisation process. The maximum sorption capacity was 743 and 849 meq kg⁻¹ for BaVC-1 and SWy-2, respectively. Hysteresis index (HI) and mobilisation factor (MF) suggest that the desorption of silver ions in BaVC-1 is about four times more conducive compared to that in SWy-2, although both materials have demonstrated a great potential for Ag⁺ pre-concentration from aqueous solutions.
显示更多 [+] 显示较少 [-]A multi-analytical approach for the assessment of the provenience of geological amber: the collection of the Earth Sciences Museum of Bari (Italy) 全文
2017
Werf, Inez Dorothé van der | Monno, Alessandro | Fico, Daniela | Germinario, Giulia | De Benedetto, Giuseppe Egidio | Sabbatini, Luigia
The Earth Sciences Museum of the University of Bari Aldo Moro (Italy) exhibits a wide collection of amber samples. These have been catalogued as Baltic amber (succinite), Sicilian amber (simetite), amber from New Jersey, Apennine amber and New Zealand copaline. However, some samples revealed to be erroneously classified as a consequence of incorrect information on the labels or in the museum catalogue. This may be due to historical forgeries, as is often the case of simetite, or to a possible exchange of samples that probably occurred during the displacement of the museum collection from the Central University Building to the Geo-environmental and Earth Sciences Department. In this study, all amber samples were systematically investigated with long wave UV rays, attenuated total reflectance (ATR), Fourier transform infrared (FTIR) spectroscopy and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) using on-line thermally assisted hydrolysis and methylation. The combined use of the latter two analytical techniques allowed for a complete characterisation of the ambers, whereas UV fluorescence showed to be of little value. The compositional data could be used for a better classification and valorisation of the amber samples of the museum collection. Two of the purported amber samples were shown to be copal, while four others are ambers but had been wrongly classified. Moreover, for some samples, it could be established that they had been subjected to treatment with a drying oil.
显示更多 [+] 显示较少 [-]A soil biotechnology system for wastewater treatment: technical, hygiene, environmental LCA and economic aspects 全文
2017
Kamble, Sheetal Jaisingh | Chakravarthy, Yogita | Singh, Anju | Chubilleau, Caroline | Starkl, Markus | Bawa, Itee
Soil biotechnology (SBT) is a green engineering approach for wastewater treatment and recycling. Five SBT units located in the Mumbai region were under consideration of which holistic assessment of two SBT plants was carried out considering its technical, environmental and economic aspects and was compared with published research of other three. LCA has been done to evaluate the environmental impacts of construction and operation phase of SBT. Chemical oxygen demand (COD) and biochemical oxygen demand (BOD) removal of more than 90% can be achieved using this technology. Also, the nutrient removal proficiency (nitrate, nitrite, ammoniacal nitrogen, TKN, total nitrogen and phosphates) of this technique is good. On the other hand, SBT has low annual operation and maintenance cost, comparable to land-based systems and lower than conventional or advanced technologies. From the life cycle impact assessment, the main contributors for overall impact from the plant were identified as electricity consumption, discharges of COD, P-PO₄ ³⁻ and N-NH₄ ⁺ and disposal of sludge. The construction phase was found to have significantly more impact than the operation phase of the plant. This study suggests plant I is not relatively as efficient enough regarding sanitation. SBT provides several benefits over other conventional technologies for wastewater treatment. It is based on a bio-conversion process and is practically maintenance free. It does not produce any odorous bio-sludge and consumes the least energy.
显示更多 [+] 显示较少 [-]