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251.
Merlin Aydın Hale Tozlu Sebnem Kemaloglu Ayse Aytac Guralp Ozkoc 《Journal of Polymers and the Environment》2011,19(1):11-17
In this study, the influence of alkali (NaOH) treatment on the mechanical, thermal and morphological properties of eco-composites
of short flax fiber/poly(lactic acid) (PLA) was investigated. SEM analysis conducted on alkali treated flax fibers showed
that the packed structure of the fibrils was deformed by the removal non-cellulosic materials. The fibrils were separated
from each other and the surface roughness of the alkali treated flax fibers was improved. The mechanical tests indicated that
the modulus of the untreated fiber/PLA composites was higher than that of PLA; on the other hand the modulus of alkali treated
flax fiber/PLA was lower than PLA. Thermal properties of the PLA in the treated flax fiber composites were also affected.
Tg values of treated flax fiber composites were lowered by nearly 10 °C for 10% NaOH treatment and 15 °C for 30% NaOH treatment.
A bimodal melting behavior was observed for treated fiber composites different than both of neat PLA and untreated fiber composites.
Furthermore, wide angle X-ray diffraction analysis showed that the crystalline structure of cellulose of flax fibers changed
from cellulose-I structure to cellulose-II. 相似文献
252.
F.P. Duval S. Quellec A. Trémier C. Druilhe F. Mariette 《Waste management (New York, N.Y.)》2010,30(4):610-619
Sludge from a slaughter-house wastewater plant, and mixtures of bulking agent (crushed wood pallet) and sludge were studied by Nuclear Magnetic Resonance (NMR). The NMR spin–spin relaxation (T2) and spin–lattice relaxation (T1) signals for sludge, wet crushed wood pallet and mixtures of sludge and bulking agent were decomposed into three relaxation time components. Each relaxation time component was explained by a non-homogeneous water distribution on a microscopic length scale and by the porosity of the material. For all samples, the T2 relaxation time value of each component was directly related to the dry matter content. The addition of wet crushed wood to sludge induced a decrease in the relaxation time, explained by water transfer between the sludge and the wood.Magnetic Resonance Imaging (MRI) and respirometric measurements were performed on sludge and wood mixtures. MR images of the mixtures were successfully obtained at different biodegradation states. Based on specific NMR measurements in an identified area located in the MRI cells, the results showed that grey levels of MR images reflected dry matter content. This preliminary study showed that MRI would be a powerful tool to measure water distribution in sludge and bulking agent mixtures and highlights the potential of this technique to increase the understanding of sludge composting. 相似文献
253.
R. Baciocchi G. Costa E. Lategano C. Marini A. Polettini R. Pomi P. Postorino S. Rocca 《Waste management (New York, N.Y.)》2010,30(7):1310-1317
This paper investigates the effects of accelerated carbonation on the characteristics of bottom ash from refuse derived fuel (RDF) incineration, in terms of CO2 uptake, heavy metal leaching and mineralogy of different particle size fractions. Accelerated aqueous carbonation batch experiments were performed to assess the influence of operating parameters (temperature, CO2 pressure and L/S ratio) on reaction kinetics. Pressure was found to be the most relevant parameter affecting the carbonation yield. This was also found to be largely dependent on the specific BA fraction treated, with CO2 uptakes ranging from ~4% for the coarse fractions to ~14% for the finest one. Carbonation affected both the mineralogical characteristics of bottom ash, with the appearance of neo-formation minerals, and the leaching behaviour of the material, which was found to be mainly related to the change upon carbonation in the natural pH of the ash. 相似文献
254.
255.
Patrick T.I. Lam Edwin H.W. Chan C.S. Poon C.K. Chau K.P. Chun 《Journal of environmental management》2010,91(3):654-661
Green specifications constitute one of the important elements in green construction. New sustainability requirements and changing priorities in construction management have spurred the emerging green specifications to a faster pace of development. A cross-sectional survey has been conducted in Hong Kong in 2007 to identify principal factors leading to the success of preparing green specifications. Based on extensive construction management literature, 20 variables concerning sustainable construction were summarized. Using the Mann–Whitney U-test, the subtle differences between stakeholders in specifying construction work have been detected even with the high consistency of the responses among the groups. Moreover, five independent factors for successful specification of green construction have been categorized by factor analysis. They are related to (1) green technology and techniques, (2) reliability and quality of specification, (3) leadership and responsibility, (4) stakeholder involvement, and (5) guide and benchmarking systems. Whilst the first and fourth factors are generally more important, different stakeholder groups have different emphases. The results of the survey have been validated against established principles. 相似文献
256.
A. Durán J.M. Monteagudo I. San Martín M. Aguirre 《Journal of environmental management》2010,91(9):1840-1846
The aim of this work was to study the mineralization of wastewater effluent from an integrated-gasification combined-cycle (IGCC) power station sited in Spain to meet the requirements of future environmental legislation. This study was done in a pilot plant using a homogeneous photo-Fenton oxidation process with continuous addition of H2O2 and air to the system.The mineralization process was found to follow pseudo-first-order kinetics. Experimental kinetic constants were fitted using neural networks (NNs). The NNs model reproduced the experimental data to within a 90% confidence level and allowed the simulation of the process for any values of the parameters within the experimental range studied. At the optimum conditions (H2O2 flow rate = 120 mL/h, [Fe(II)] = 7.6 mg/L, pH = 3.75 and air flow rate = 1 m3/h), a 90% mineralization was achieved in 150 min.Determination of the hydrogen peroxide consumed and remaining in the water revealed that 1.2 mol of H2O2 was consumed per each mol of total organic carbon removed from solution. This result confirmed that an excess of dissolved H2O2 was needed to achieve high mineralization rates, so continuous addition of peroxide is recommended for industrial application of this process.Air flow slightly improved the mineralization rate due to the formation of peroxo-organic radicals which enhanced the oxidation process. 相似文献
257.
Michael J. McFarland Glenn R. Palmer Arthur C. Olivas 《Journal of environmental management》2010,91(4):927-931
The US Environmental Protection Agency (EPA) has established EPA Reference Method 9 (Method 9) as the preferred enforcement approach for verifying compliance with federal visible opacity standards. While Method 9 has an extensive history of successful employment, reliance on human observers to quantify visible emissions is inherently subjective, a characteristic that exposes Method 9 results to claims of inaccuracy, bias and, in some cases, outright fraud.The Digital Opacity Compliance System (DOCS), which employs commercial-off-the-shelf digital photography coupled with simple computer processing, is a new approach for quantifying visible opacity. The DOCS technology has been previously demonstrated to meet and, in many cases, surpass the Method 9 accuracy and reliability standards (McFarland et al., 2006). Beyond its performance relative to Method 9, DOCS provides a permanent visual record of opacity, a vital feature in legal compliance challenges.In recent DOCS field testing, the opacity analysis of two hundred and forty one (241) regulated air emissions from the following industrial processes: 1) industrial scrubbers, 2) emergency generators, 3) asphalt paving, 4) steel production and 5) incineration indicated that Method 9 and DOCS were statistically equivalent at the 99% confidence level. However, a life cycle cost analysis demonstrated that implementation of DOCS could potentially save a facility $15,732 per trained opacity observer compared to utilization of Method 9. 相似文献
258.
Patrick C. Tobin Julie Van Stappen Laura M. Blackburn 《Journal of environmental management》2010,91(10):1991-1996
The introduction of non-native species has accelerated due to increasing levels of global trade and travel, threatening the composition and function of ecosystems. Upon arrival and successful establishment, biological invaders begin to spread and often do so with considerable assistance from humans. Recreational areas can be especially prone to the problem of accidental non-native species transport given the number of visitors that arrive from geographically diverse areas. In this paper, we examine camping permit data to the Apostle Islands National Lakeshore in northwestern Wisconsin, USA, from 1999 to 2007 relative to gypsy moth distribution, phenology and outbreak data. During this time, gypsy moth populations became established in this area ahead of the moving population front of the gypsy moth, suggesting anthropogenic introduction. The permit data revealed that the majority of visitors arrived from outside of the gypsy moth established area. However, there was a consistent yearly trend of visitors that arrived from areas of high gypsy moth populations and who arrived during the gypsy moth life stage (egg masses) most likely to be successfully introduced. Using available data on the gypsy moth and its relationship to camping permit data, we describe how recreational managers could optimize park strategies to mitigate unwanted introductions of the gypsy moth as well as develop analogous strategies for managing other biological invaders in recreational areas. 相似文献
259.
S. Mancebo Quintana B. Martín Ramos M.Á. Casermeiro Martínez I. Otero Pastor 《Journal of environmental management》2010,91(5):1087-1096
The aim of the present work is to design a model for evaluating the impact of planned infrastructures on species survival at the territorial scale by calculating a connectivity index. The method developed involves determining the effective distance of displacement between patches of the same habitat, simplifying earlier models so that there is no dependence on specific variables for each species. A case study is presented in which the model was used to assess the impact of the forthcoming roads and railways included in the Spanish Strategic Infrastructure and Transport Plan (PEIT, in its Spanish initials).This study took into account the habitats of peninsular Spain, which occupies an area of some 500,000 km2. In this territory, the areas deemed to provide natural habitats are defined by Directive 92/43/EEC. The impact of new infrastructures on connectivity was assessed by comparing two scenarios, with and without the plan, for the major new road and railway networks. The calculation of the connectivity index (CI) requires the use of a raster methodology based on the Arc/Info geographical information system (GIS). The actual calculation was performed using a program written in Arc/Info Macro Language (AML); this program is available in FragtULs (Mancebo Quintana, 2007), a set of tools for calculating indicators of fragmentation caused by transport infrastructure (http://topografia.montes.upm.es/fragtuls.html).The indicator of connectivity proposed allows the estimation of the connectivity between all the patches of a territory, with no artificial (non-ecologically based) boundaries imposed. The model proposed appears to be a useful tool for the analysis of fragmentation caused by plans for large territories. 相似文献
260.
Maria A. García-Valiñas Roberto Martínez-Espiñeira Francisco González-Gómez 《Journal of environmental management》2010,91(12):2696-2706
Using information on a basic or “lifeline” level of domestic water use obtained from a water demand function based on a Stone–Geary utility function, a minimum water threshold of 128 m3 per household per year was estimated in a sample of municipalities in Southern Spain. As a second objective, water affordability indexes were then calculated that relate the cost of such lifeline to average municipal income levels. The analysis of the factors behind the differences in that ratio across Andalusian municipalities shows that the relative cost of purchasing the lifeline appears inversely related to average income levels, revealing an element of regressivity in the component of water tariffs affecting the least superfluous part of the household’s consumption. The main policy recommendation would involve redesigning water tariffs in order to improve access for lower income households to an amount of water sufficient to cover their basic needs. The proposed methodology could be applied to other geographical areas, both from developed and from developing countries, in order to analyze the degree of progressivity of the water tariffs currently in effect and in order to guide the design of more equitable regulatory policies. 相似文献