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641.
The aim of this research activity is to investigate the environmental impact of different thermal treatments of waste electric and electronic equipment (WEEE), applying a life cycle assessment methodology. Two scenarios were assessed, which both allow the recovery of bromine: (A) the co-combustion of WEEE and green waste in a municipal solid waste combustion plant, and (B) the staged-gasification of WEEE and combustion of produced syngas in gas turbines. Mass and energy balances on the two scenarios were set and the analysis of the life cycle inventory and the life cycle impact assessment were conducted. Two impact assessment methods (Ecoindicator 99 and Impact 2002+) were slightly modified and then used with both scenarios. The results showed that scenario B (staged-gasification) had a potentially smaller environmental impact than scenario A (co-combustion). In particular, the thermal treatment of staged-gasification was more energy efficient than co-combustion, and therefore scenario B performed better than scenario A, mainly in the impact categories of "fossil fuels" and "climate change". Moreover, the results showed that scenario B allows a higher recovery of bromine than scenario A; however, Br recovery leads to environmental benefits for both the scenarios. Finally the study demonstrates that WEEE thermal treatment for energy and matter recovery is an eco-efficient way to dispose of this kind of waste. 相似文献
642.
Castrillón L Fernández-Nava Y Marañón E García L Berrueta J 《Waste management (New York, N.Y.)》2009,29(2):761-766
Cattle manure from a dairy farm was treated in order to reduce its pollution potential. The manure came from a farm with 120 cows kept in stables in a free stall barn. As pretreatment, the manure is usually filtered on the farm using a screw press separator with a 0.5 mm mesh. Approximately 70% of the total filtered volume passes through the screen, thus constituting the liquid fraction. This fraction, with a composition of around 64,500 mg COD/l, 5770 mg total-N/l and 800 mg total-P/l, was subjected to centrifugation followed by a two-step biological treatment (anoxic-aerobic) to reduce organic matter (COD), nitrogen and phosphorus compounds. Centrifugation led to the following removal efficiencies: 35% total solids, 60% COD, 75% total phosphorus and 20% total nitrogen (mainly organic nitrogen). With the subsequent anoxic-aerobic treatment, average removal efficiencies of 85% for COD, 90% for total phosphorus and 75% for total nitrogen were achieved. 相似文献
643.
Machado SL Carvalho MF Gourc JP Vilar OM do Nascimento JC 《Waste management (New York, N.Y.)》2009,29(1):153-161
This paper deals with the use of simplified methods to predict methane generation in tropical landfills. Methane recovery data obtained on site as part of a research program being carried out at the Metropolitan Landfill, Salvador, Brazil, is analyzed and used to obtain field methane generation over time. Laboratory data from MSW samples of different ages are presented and discussed; and simplified procedures to estimate the methane generation potential, Lo, and the constant related to the biodegradation rate, k are applied. The first order decay method is used to fit field and laboratory results. It is demonstrated that despite the assumptions and the simplicity of the adopted laboratory procedures, the values Lo and k obtained are very close to those measured in the field, thus making this kind of analysis very attractive for first approach purposes. 相似文献
644.
Aging and compressibility of municipal solid wastes 总被引:2,自引:0,他引:2
The expansion of a municipal solid waste (MSW) landfill requires the ability to predict settlement behavior of the existing landfill. The practice of using a single compressibility value when performing a settlement analysis may lead to inaccurate predictions. This paper gives consideration to changes in the mechanical compressibility of MSW as a function of the fill age of MSW as well as the embedding depth of MSW. Borehole samples representative of various fill ages were obtained from five boreholes drilled to the bottom of the Qizhishan landfill in Suzhou, China. Thirty-one borehole samples were used to perform confined compression tests. Waste composition and volume-mass properties (i.e., unit weight, void ratio, and water content) were measured on all the samples. The test results showed that the compressible components of the MSW (i.e., organics, plastics, paper, wood and textiles) decreased with an increase in the fill age. The in situ void ratio of the MSW was shown to decrease with depth into the landfill. The compression index, Cc, was observed to decrease from 1.0 to 0.3 with depth into the landfill. Settlement analyses were performed on the existing landfill, demonstrating that the variation of MSW compressibility with fill age or depth should be taken into account in the settlement prediction. 相似文献
645.
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647.
The general public, government regulators, and environmental organizations are increasingly demanding industries to reduce their environmental impacts and report progress. This in turn resulted in numerous requirements for reporting environmental data. Environmental assessments are a useful tool in gathering and documenting this data. The assessments also assist decision makers to quantify impacts of their activities and plan for appropriate mitigation measures. There are different types of environmental assessments, each having specific purpose(s) and addressing specific audience(s). This paper gives an overview of common environmental concerns associated with oil and gas industry and shares insights on types of environmental assessments that are widely used. It discusses general methodologies to define the scope, approach, measurement standards, and reporting. Potential challenges encountered in conducting these assessments in an international arena and under a wide variety of regulatory requirements are addressed. Practical approach in execution of these assessments is described here, and strategy in dealing with the challenges is presented. 相似文献
648.
Mario C.R. Vidal Paulo V.R. Carvalho Marcello S. Santos Isaac J.L. dos Santos 《Journal of Loss Prevention in the Process Industries》2009,22(4):516-527
This article aims to describe the characteristics of collective working situations in complex systems – especially those in nuclear power plants – related to common forms of cooperation, in order to improve systems resilience. In addition, we will try to detail some aspects of collective working situations, emphasizing the differences between various forms of control. The similarities between work activities (multi-addressed messages, linkage to regulation, central and peripheral information) are nonetheless exposed. We conclude by proposing a contribution to support systems design, thus facilitating cooperation in teamwork activities. 相似文献
649.
Govil PK Sorlie JE Murthy NN Sujatha D Reddy GL Rudolph-Lund K Krishna AK Rama Mohan K 《Environmental monitoring and assessment》2008,140(1-3):313-323
Studies on quantitative soil contamination due to heavy metals were carried out in Katedan Industrial Development Area (KIDA),
south of Hyderabad, Andhra Pradesh, India under the Indo-Norwegian Institutional Cooperation Programme. The study area falls
under a semi-arid type of climate and consists of granites and pegmatite of igneous origin belonging to the Archaean age.
There are about 300 industries dealing with dyeing, edible oil production, battery manufacturing, metal plating, chemicals,
etc. Most of the industries discharge their untreated effluents either on open land or into ditches. Solid waste from industries
is randomly dumped along roads and open grounds. Soil samples were collected throughout the industrial area and from downstream
residential areas and were analysed by X-ray Fluorescence Spectrometer for fourteen trace metals and ten major oxides. The
analytical data shows very high concentrations of lead, chromium, nickel, zinc, arsenic and cadmium through out the industrial
area. The random dumping of hazardous waste in the industrial area could be the main cause of the soil contamination spreading
by rainwater and wind. In the residential areas the local dumping is expected to be the main source as it is difficult to
foresee that rain and wind can transport the contaminants from the industrial area. If emission to air by the smokestacks
is significant, this may contribute to considerable spreading of contaminants like As, Cd and Pb throughout the area. A comparison
of the results with the Canadian Soil Quality Guidelines (SQGL) show that most of the industrial area is heavily contaminated
by As, Pb and Zn and local areas by Cr, Cu and Ni. The residential area is also contaminated by As and some small areas by
Cr, Cu, Pb and Zn. The Cd contamination is detected over large area but it is not exceeding the SQGL value. Natural background
values of As and Cr exceed the SQGL values and contribute significantly to the contamination in the residential area. However,
the availability is considerably less than anthropogenic contaminants and must therefore be assessed differently. The pre-
and post-monsoon sampling over two hydrological cycles in 2002 and 2003 indicate that the As, Cd and Pb contaminants are more
mobile and may expect to reach the groundwater. The other contaminants seem to be much more stable. The contamination is especially
serious in the industrial area as it is housing a large permanent residing population. The study not only aims at determining
the natural background levels of trace elements as a guide for future pollution monitoring but also focuses on the pollution
vulnerability of the watershed. A plan of action for remediation is recommended. 相似文献
650.
Schaefer CE do Amaral EF de Mendonça BA Oliveira H Lani JL Costa LM Fernandes Filho EI 《Environmental monitoring and assessment》2008,140(1-3):279-289
The relationships between soils attributes, soil carbon stocks and vegetation carbon stocks are poorly know in Amazonia, even
at regional scale. In this paper, we used the large and reliable soil database from Western Amazonia obtained from the RADAMBRASIL
project and recent estimates of vegetation biomass to investigate some environmental relationships, quantifying C stocks of
intact ecosystem in Western Amazonia. The results allowed separating the western Amazonia into 6 sectors, called pedo-zones:
Roraima, Rio Negro Basin, Tertiary Plateaux of the Amazon, Javari-Juruá-Purus lowland, Acre Basin and Rondonia uplands. The
highest C stock for the whole soil is observed in the Acre and in the Rio Negro sectors. In the former, this is due to the
high nutrient status and high clay activity, whereas in the latter, it is attributed to a downward carbon movement attributed
to widespread podzolization and arenization, forming spodic horizons. The youthful nature of shallow soils of the Javari-Juruá-Purus
lowlands, associated with high Al, results in a high phytomass C/soil C ratio. A similar trend was observed for the shallow
soils from the Roraima and Rondonia highlands. A consistent east–west decline in biomass carbon in the Rio Negro Basin sector
is associated with increasing rainfall and higher sand amounts. It is related to lesser C protection and greater C loss of
sandy soils, subjected to active chemical leaching and widespread podzolization. Also, these soils possess lower cation exchangeable
capacity and lower water retention capacity. Zones where deeply weathered Latosols dominate have a overall pattern of high
C sequestration, and greater than the shallower soils from the upper Amazon, west of Madeira and Negro rivers. This was attributed
to deeper incorporation of carbon in these clayey and highly pedo-bioturbated soils. The results highlight the urgent need
for refining soil data at an appropriate scale for C stocks calculations purposes in Amazonia. There is a risk of misinterpreting
C stocks in Amazonia when such great pedological variability is not taken into account. 相似文献