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1.
Journal of Polymers and the Environment - Polymer fractions from a biological matrix have been well-characterized by vibrational spectroscopy, XPS, CP/MAS 13C NMR, MALDI-TOF mass...  相似文献   

2.
Wastewater contains varieties of carbonaceous and nitrogenous compounds that undergo complicated biodegradation processes in wastewater treatment plants. How these different compounds are degraded by activated sludge in aerobic conditions is still a mystery. Researchers have been trying to interpret it using the oxygen uptake rate (OUR) derived from the respirograms of respective substrates. Several models have been proposed to interpret the substrate removal mechanisms using the experimental observations. Have we succeeded in understanding the messages by activated sludge correctly using these models? In this paper, the distinctive nature of the respirograms when activated sludge is fed with different substrates and the biokinetic models that have been developed to explain the substrate removal mechanisms using derived OUR profiles are reviewed. In addition, a sensitivity study was conducted on the recently evolved simultaneous storage and growth model to investigate the influence of key parameters on OUR profiles during the biodegradation process.  相似文献   

3.
Vinyl 2010 — nearing the target date   总被引:1,自引:1,他引:0  
For almost 10 years, Vinyl 2010 has provided original approaches to technical, environmental, and political problems relating to poly(vinyl chloride) (PVC) material cycles and waste management. On the one hand, PVC has outstanding qualities in a wide range of applications; on the other hand, concerns about potential impacts attributed to production, additives, and waste management led to calls for PVC-specific regulations and mandatory substitution in certain applications. Considering the entire life cycle of PVC products, the industry proposed a comprehensive set of measures rendering production cleaner, eliminating controversial additives, and promoting responsible management of waste, favoring recycling. Vinyl 2010 can now be regarded as a highly successful example of applying voluntary commitments instead of the more usual command and control approach from regulatory authorities.  相似文献   

4.
This paper examines the merits and the perverse effects of quality of service regulation in the performance of urban waste services when implemented alone and compares the performance of different economic regulatory methods. By means of a productivity analysis, we investigate the influence of a five-year period of regulation on the performance of Portuguese urban waste utilities using an unbalanced panel data for the period 2001-2008. Different non-parametric methods were applied to estimate the productivity change, all leading to similar outcomes. We observed a tendency of productivity decline in the urban waste utilities and concluded that in spite of the unequivocal improvements in the quality of service induced by sunshine regulation, more should be done as far as economic regulation is concerned. We also found that the use of sunshine regulation together with low incentive economic regulatory methods is not positive, leading to overinvestment rather than to value for money.  相似文献   

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Journal of Material Cycles and Waste Management - In Japan, recycled concrete aggregate (RCA) and recycled-aggregate concrete (RAC) are standardized in the Japanese Industrial Standards (JIS) A...  相似文献   

7.
Journal of Polymers and the Environment - Nowadays, there is a need to obtain eco-friendly materials, especially plastics that are responsible for most of the environmental pollution. In this...  相似文献   

8.
There is increasing concern about landfilling of biodegradable wastes. Therefore, biological treatment processes such as composting and biogasification have been considered as alternative strategies for managing those wastes. In this work, life cycle assessment was employed to compare the environmental impacts of landfilling, composting, and biological treatment of municipal solid waste in S?o Paulo City, Brazil. Energy consumption, recovered resources, and emissions to air and water were quantified and analyzed in terms of their potential contribution to global warming, acidification, and nutrient enrichment impact. The results demonstrated that processes that require high levels of energy consumption, such as wastewater treatment, play an important role in the outcome of environmental impact potentials. It was found that the landfilling of all waste is generally the worst strategy from an environmental point of view. However, significant reductions in the resulting impacts can be accomplished through biogasification and composting of the biodegradable fraction. Regarding composting, the application of a biofilter for gas treatment reduced significantly the gaseous emissions.  相似文献   

9.
Journal of Material Cycles and Waste Management - The dry climate of the Qinghai–Tibet Plateau causes the rapid loss of moisture in composting piles, which affects dynamics of the composting...  相似文献   

10.
The coastal region affected by the Exxon Valdez oil spill, although a beautiful and sensitive maritime wilderness with bountiful fish and wildlife, was not a pristine environment in 1989. Prior to the spill, Prince William Sound and the northern Gulf of Alaska region had experienced extensive human impacts from the commercial fur trade, commercial sea-mammal hunting, commercial fishing, logging, mining and introduced exotic species including foxes, Sitka black-tailed deer and hatchery-reared pink salmon. The spill occurred in a scenic area that was (and is) paradoxically both the source of subsistence food for local residents and the scene of extensive natural resource exploitation.Contrary to media sound bites and news headlines, the Exxon Valdez oil spill did not destroy a pristine wilderness. The Russian and American fur traders, commercial whalers and commercial fishermen, miners, loggers, fox farmers and military construction crews had transformed the region long before March 24, 1989. The Exxon Valdez spill was an important chapter in the history of human impacts to the area’s maritime ecosystem, but it was not, as many continue to claim, the mother of all environmental impacts in the region.  相似文献   

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Performance results obtained from a 6200 ton demonstration-scale anaerobic bioreactor, constructed on the Pacara Pintada Landfill in Tucumán, Argentina, are described. The operational aspects over a 30-month period for the Tucumán bioreactor demonstrate the ability to maintain the bioreactor in the mesophilic range, with the result that the generation and collection of the biogas has been maintained at accelerated rates with a rate constant of approximately 0.5 year(-1). Field measurements of metal concentrations in leachate indicated significant attenuation over time. Refuse subsidence, measured over a 28-month period, ranged from 4% to 19%, with an average of 11% subsidence across the Tucumán cell.  相似文献   

13.
This article deals with a methodology for the design of routes for the "bin to bin" (BTB) collection of paper and cardboard waste (PCB) from small businesses, as well as with the new location and calculation of the number of containers needed in the streets for both commercial and non-commercial use due to the large amount of PCB deposited in them. This study was carried out in five shopping areas of the city of Leganés (Community of Madrid, Spain). One of the characteristics of the area is a high density of population and urban traffic. The tool used is the Geographical Information System (GIS-Arc-View). With it we can generate PCB points of high population density in commercial streets based on territorial analysis. We placed the special routes and the new container locations within a distance of 60 m of these collection points (CPT). The system calculates and optimizes six routes according to different urban restrictions. Finally, we provided service to 59% of the shops, which generate almost 82% of the PCB waste, using 160 min per day to collect 1027 kg of high quality PCB. If we compare the system with the system in place previously, we can conclude that the "bin to bin" (BTB) system improves the quality of the PCB in the containers, avoiding overflow and reducing the percentage of rejected material.  相似文献   

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Important reactive minerals are commonly created during in situ groundwater remediation activities; for example, iron sulfides formed during enhanced reduction approaches can abiotically degrade many chlorinated solvents. However, cost-effective tools to evaluate these treatment processes in field applications are limited and the collection of samples to evaluate in situ mineral formation is costly due to drilling requirements. The new passive Min-Trap sampler is a simple and cost-effective tool that can directly measure the formation of reactive minerals in situ without the need for additional drilling or soil core collection. The methods presented here describe how Min-Traps deployed in conventional monitoring wells can measure reactive minerals and how these minerals can be identified through commercially available analytical methods. Several examples are presented that show how Min-Traps can be used to characterize the rate and spatial variability of reactive mineral precipitation and these data may support operation and optimization decisions.  相似文献   

16.
Journal of Material Cycles and Waste Management - E-waste is becoming a concern due to its toxic content and serious pollution effect. Many studies have focused on the detrimental impacts of...  相似文献   

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18.
We are presenting here a multi-isotope approach (δ13C and δ18O of CO2; δ13C and δD of CH4) to assess (i) the level(s) of methane oxidation during waste biodegradation and its migration through a landfill cover in Sonzay (France), and (ii) its contribution to the atmospheric CO2 levels above the surface. The isotope approach is compared to the more conventional mass balance approach. Results from the two techniques are comparable and show that the CH4 oxidation under the landfill cover is heterogenous, with low oxidation percentages in samples showing high biogas fluxes, which was expected in clay covers presenting fissures, through which CH4 is rapidly transported. At shallow depth, more immobile biogas pockets show a higher level of CH4 oxidation by the methanotrophic bacteria. δ13C of CO2 samples taken at different heights (from below the cover up to 8 m above the ground level) were also used to identify and assess the relative contributions of its main sources both under the landfill cover and in the surrounding atmosphere.  相似文献   

19.
This work aims at analyzing the energy efficiency of the chemical recycling process of polylactic acid (PLA) and its sustainability from an environmental point of view. The results show that the production of lactic acid from chemical depolymerization of PLA is preferable, from an energy point of view, to the production of lactic acid by glucose fermentation. The study also shows that the environmental footprint of the analyzed process is larger than that of the PLA mechanical recycling.  相似文献   

20.
This paper describes the present situation of waste incineration in Europe and discusses the problems faced in the future when the Directives of the European Community will be implemented on waste management. As an example, the status of thermal waste treatment in Germany is dealt with in detail. A point addressed is that public acceptance of incineration can only be increased if the public is aware of the conditions governing waste avoidance and recycling and if these conditions are actually realized. This means, prior to incineration, recyclable or compostable materials should be separated, and only then can the remaining amounts of wastes be treated before being deposited. The main aim of the treatment process is to reduce the hazard potential posed by waste and to meet the landfill requirements laid down in the German Technical Instructions for Municipal Waste.  相似文献   

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