توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱A mathmatical Model for Cadmium Removal using A sulfate Reducing Educing Bacterium: Desulfovibrio alaskensis 6SR
اطلاعات انتشار: International Journal Of Environmental Research، هفتم،شماره۲، Spring ۲۰۱۳، سال
تعداد صفحات: ۱۲
In this work, an unstructured–type mathematical model was developed to simulatecadmium (Cd2+) removal by Desulfovibrio alaskensis 6SR, which is a recently described sulfate reducing bacterium, whose capacity for removing heavy metals are being studied. Three processes are considered in the model: 1) the sulfate reduction process, 2) the consumption of lactate as carbon source, and 3) the metal removal. The model was tested with different initial Cd2+ concentrations (50, 100, 170, and 190 mg\L), and it accurately predicted the behavior of experimental data with satisfactory correlation coefficients (R2>0.97). In addition, the model showed that the H2S productionrate and initial concentration of Cd2+ are key operating variables in a bioreactor. Desulfovibrio alaskensis 6SR was able to remove more than 99.9% of cadmium in a batch process, where the initial concentration was 170 mg\L. The model, applied to a continuous process, predicted a maximum Cd2+ removal of 99.1% with the same initial concentration. Also, the model predicted the inhibitory effect of initial Cd2+ concentrations above 190 mg\L. The mathematical model developed can be used foroptimization and control purposes.

۲Sewage Sludge Application in Mediterranean Agricultural soils: Effects of Dose on the Soil Carbon Cycle
اطلاعات انتشار: International Journal Of Environmental Research، هفتم،شماره۴، Autumn ۲۰۱۳، سال
تعداد صفحات: ۱۲
This work investigates the effect of the application rate and type of sludge throughout the soil carbon cycle in a semiarid Mediterranean agro–ecosystem. We study the two–year evolution of the various pools of soil organic and inorganic carbon and their influence on soil respiration. We applied three rates ( , 80 and 160 Mg\ha) of two types of sludge –aerobically and anaerobically digested sewage sludge– in a calcareous Mediterranean soil. The study area is located in the southeast of Madrid (Spain) and is characterised by a Mediterranean climate with a marked seasonal and daily contrast. We analysed soil organic carbon, CO2 emissions, organic carbon fractions, soluble carbon, and inorganic carbon forms. Measurements were madeat three times over two years, and bimonthly for organic carbon and CO2.The results show that sludge type and rateof applicationexerta significant influence throughout the soil carbon cycle. Aerobic sludge has a greater effect over the short–term. Anaerobic sludge treatment appears to have less effect on the cycle at the beginning of the amendment, but is prolonged over time, as the differences with untreated soil persist even after two years. The application of organic amendments in calcareous Mediterranean soils also modifies the inorganic carbon pools and greatly increases the soil soluble hydrogen carbonates. All of these results are reflected in the rates of soil CO2 emissions, with the highest values recorded in soils amended with aerobic sludge. Our data points to the advisability of a review of the European Union’s recommendations regarding sludge and agriculture. We propose includinga sludge stabilization process and recommended application ratesaccording to the effects on soil biogeochemical cycles.

۳Environmental Orientation as a Determinant of Innovation Performance in Young SMEs
نویسنده(ها): ، ، ، ، ، ، ، ، ، ، ، ، ، ، ،
اطلاعات انتشار: International Journal Of Environmental Research، هشتم،شماره۳، Summer ۲۰۱۴، سال
تعداد صفحات: ۸
The popular press, as well as most academic literature, claims that innovation activities areinherently linked to higher company performance. Successful innovations usually increase the firm’s market scope or reduce costs, helping firms to obtain superior benefits. Therefore, most innovations are developed with those objectives in mind. Environmental orientation is defined as the managerial recognition of the significance of the impact a company has on the environment, and the need to minimize such impact. Nowadays, environmental motivation for innovation is becoming more and more common as firms are more aware of the consequences of their activities and attempt to be socially responsible. However, most literature on innovation is focused on R&D and on large mature firms, practically neglecting small and medium sized Enterprises – SMEs–, as does the literature on corporate social responsibility. In this paper, we focus on a sample of 1337 start–up SMEs less than 10 years old, from which we obtained information regarding their innovation activities. Our results show that in comparison to cost–oriented innovations, environmental orientation in the development of innovations increases performance.

۴Application of Response Surface Methodology (RSM) for Culture Conditions and Biomass Production of Psychrophilic Microalgae Isolated from High Mountains Lake During the ice–free Season
نویسنده(ها): ، ، ، ، ، ، ، ، ، ، ، ، ، ، ، ، ، ، ، ،
اطلاعات انتشار: International Journal Of Environmental Research، هشتم،شماره۳، Summer ۲۰۱۴، سال
تعداد صفحات: ۱۴
Many studies on cold environments have been developed over the past two decades. High mountain freshwater presents high variability of nutrients and chemico–physical parameters, showing variations of pH, oxygen concentration, metals and temperature throughout the year. National Park of Sierra Nevada (Granada, Spain) (37°032 N 03°182 W), has almost 40 lakes that are reported to be both endemic and oligotrophic. However, very little information about their microbial diversity can be found in literature. In this work, a Response Surface Methodology (RSM) was used to find best nutritional conditions for the isolation of psychrophilic microalgae from La Caldera Lake. The results showed that best culture medium, was the Rodriguez–Lopez medium (RL); data were adjusted to a quadratic prediction model reporting a biomass concentration over 600 mg\L at 10 and 20ºC. In this paper, the diversity of culturable freshwater microalgae in the La Caldera Lake was observed by PCR using specific primers for eukaryotic 18S rRNA genes. Samples were taken in early July and late Agust, 2011. In July presence of strains belonging to the Eustigmatophyceae, Bacillariophyceae, Trebouxiophyceae, Chlorophyceae and Scenedesmaceae families were found. In August, only microalgae from the Eustigmatophyceae, Trebouxiophyceae, Chlorophyceae and Scenedesmaceae families were found. An individual culture of each isolated strain was carried out. Microalgae S21 had phylogenetic similitude with Chlorophyceae, and showed best growth being biomass concentration in RL 393.73 mg\L and 128.52 mg\L at 20ºC and 10ºC, respectively. Moreover, specific growth rates (μmax), 0.25\h and 0.13\h at 20ºC and 10ºC, respectively, were detected for strain S21.

۵TemporalTrends ofMetal Extractability in Calcareous soilsAffected by Soil Constituents andMetal Contamination Levels
نویسنده(ها): ، ، ، ، ، ، ، ، ، ، ،
اطلاعات انتشار: International Journal Of Environmental Research، نهم،شماره۱، Winter ۲۰۱۵، سال
تعداد صفحات: ۱۰
The role played by soil constituents in governing temporal trends of metal mobility in calcareous Mediterranean soils deserves special attention due to the particular soil and climate characteristics. Reactions occurring during the aging modify the metal mobility over time, and the rate of metal application and type of soil can be decisive in the outcome of aging reactions in soils. The aim of the present work was to investigate the role that both metal dose and soil constituents play in temporal trends of (potential) metal mobility in soils offering a natural gradient of carbonate and whose remaining soil constituents differed. Soil samples were spiked with a mixture of Cd, Cu, Pb and Zn at two levels and then left aging for 12 months incubation. Metals were extracted at different time intervals (1 day, 1, 3, 6 and 12 months) with one–step extraction methods to estimate immediate metal mobility (NaNO3) and potential metal mobility (diethylene triamine pentaacetic acid –DTPA–). At both levels of contamination, NaNO3–extractable Cd, Cu and Zn concentration values reached equilibrium within the period of incubation. Temporal trend of immediate metal mobility was governed by carbonate fraction for Cd and Cu and by the finest carbonate fraction for Zn. In the case of potential metal mobility, DPTA–extractable metal concentrations did not reach equilibrium within the incubation time. In this case, the combined action of carbonate, organic, Fe–oxide and clay fractions were decisive to define the different temporal trends observed for each metal and level.

۶Building Renewal in Low Income Housing Estates – A Brazilian Case Study (Text in Persian)
اطلاعات انتشار: Asian journal of civil engineering، چهاردهم،شماره۵، Oct ۲۰۱۳، سال
تعداد صفحات: ۲۶
This paper exposes a design methodology for building renewal, which is oriented towards adding sustainability, value, and flexibility. It considers environmental and economic feasibility based on embodied energy in materials, conventional budgets and hedonic price models. A process of design simulation was developed, focusing on a typical housing estate, in Porto Alegre, Brazil. The main results of which indicate that there is potential for increasing their value. Building renewal is a form of recycling and has influence on social, economic, and environmental issues. This work contributes to the discussion of alternatives to the low income housing deficit in Brazil.
نمایش نتایج ۱ تا ۶ از میان ۶ نتیجه