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961.
962.
Effects of Acidification and its Mitigation with Lime and Wood Ash on Forest Soil Processes: A Review 总被引:6,自引:0,他引:6
Lundström U. S. Bain D. C. Taylor A. F. S. van Hees P. A. W. 《Water, Air, & Soil Pollution: Focus》2003,3(4):5-28
Anthropogenic acid deposition causes forest soil acidification and perturbation of the soil forming processes. The impact of soil acidification on tree growth is discussed in view of the role of mycorrhizal fungi in weathering and nutrient uptake. A review has been carried out of experiments involving treatments of forest soil by lime and wood ash, where soil properties and soil solution composition have been investigated. Results from these experiments in Europe and North America are summarized. In general, the content of C in the mor layer decreased as a result of treatment due to higher microbial activity and soil respiration as well as increased leakage of DOC. In addition, the content of N in the mor layer, in general, decreased after treatment and there are occasional peaks of high NO3concentrations in soil solution. In nearly all reviewed investigations the pH of the deep mineral soil solution decreased and Al, SO4and NO3concentrations increased after treatment. These effects are probably due to the high ionic strength and increased microbial activity as a consequence of the treatments. In the soil, pH, CEC and base saturation increased in the upper horizons, but decreases in the upper mineral soil are also reported. In general, there was no increase in tree growth as a result of these treatments. The positive effects of the treatments on soil processes and tree growth are therefore questionable. In view of these conclusions, an investigation was carried out on the soil and soil solution chemistry and the role of mycorrhizal fungi in a spruce stand treated with two doses of lime and another treated with lime/ash in southern Sweden. The results of this investigation is reported in this volume. 相似文献
963.
964.
The purpose of research was to test the effectiveness of a prototype of a turning machine and to evaluate the feasability of a farm-scale composting process of the solid fraction of swine manure. A qualitative evaluation of the process and final product was made by monitoring the following parameters: process temperature, oxygen concentration inside the biomass, gaseous emissions (CH4, CO2, NH3, N2O), respiration index, humification index, total and volatile solids, carbon and nitrogen, pH and microbial load. The prototype proved to be very effective from a technical-operational point of view. The composting process exhibited a typical time-history, characterised by a thermophilic phase followed by a curing phase [Chiumenti, A., Chiumenti, R., Diaz, L.F., Savage, G.M., Eggerth, L.L., Goldstein, N., 2005. Modern Composting Technologies. BioCycle-JG Press, Emmaus, PA, USA]. Gas emissions from compost the windrow were more intense during the active phase of the process and showed a decreasing trend from the thermophilic to the curing phase. The final compost was characterized by good qualitative characteristics, a significant level of humification [Rossi, L., Piccinini, S., 1999. La qualità agronomica dei compost derivanti da liquami suinicoli. (Agronomic quality of swine manure compost). L'informatore Agrario 38, 29-31] and no odor emissions. This method of managing manure represents an effective, low cost approach that could be an interesting opportunity for swine farms. 相似文献
965.
P.-A. Dastous J. Nikiema G. Soreanu L. Bibeau M. Heitz 《Water, Air, & Soil Pollution: Focus》2008,8(3-4):275-285
This study presents the experimental results obtained during long-term operation of two biofilters treating two alcohols:
methanol and ethanol. The biofilters used for this purpose were previously packed with a compost material made from tobacco
processing residues. The alcohols concentrations tested lay between 0.40 and 3.20 g/m3 for methanol, and 0.55 and 5.05 g/m3 for ethanol. The empty bed residence time in each biofilter was 60 s. Biofilter inlet loads of less than 190 and 300 g/m3/h for the methanol and ethanol additions respectively, were thereafter evaluated. In addition, the concentrations of nutrient
nitrogen were also varied, from 0.1 to 2.0 g-N/l and from 0.3 to 11.3 g-N/l for the ethanol and the methanol, respectively.
The results thus obtained have made it possible to select the optimal nitrogen concentrations which, for the cases examined,
turn out to be 0.3 g-N/l and between 2 and 3.8 g-N/l for the ethanol and methanol substrates, respectively. The maximum elimination
capacities obtained in this study were 82 and 150 g/m3/h, respectively for the methanol and ethanol cases. It was therefore concluded that, for a readily biodegradable compound
such as ethanol, the nitrogen requirement is substantially lower than that needed for the methanol degradation, the latter
appearing to be more difficult to degrade biologically under similar operating conditions. The production rate of the co-product
carbon dioxide during methanol and ethanol biofiltration was also investigated. Also, a good correlation was found to exist
between the temperature and the conversion achieved in the biofilter. 相似文献
966.
Chun Wai Lee Dennis G. Tabor Kenneth A. Cowen 《Journal of Material Cycles and Waste Management》2008,10(1):38-45
The performance of four dioxin emission monitors, including two long-term sampling devices, the Dioxin-MonitoringSystem (DMS)
and AMESA (the adsorption method for sampling dioxins and furans), and two semireal-time continuous monitors, the resonance
ionization with multimirror photon accumulation time-of-flight mass spectrometer (RIMMPA-TOFMS) and the jet resonance-enhanced
multiphoton ionization (jet-REMPI) system were tested. A package boiler burning a simulated chlorinated hazardous waste was
used for a total of nine tests. Reference samples were collected during each test and analyzed for polychlorinated dibenzodioxins
and dibenzofurans (PCDDs/Fs) using gas chromatography mass spectrometry. The PCDD/F concentrations of the reference samples
measured by EPA Method 23 ranged from 0.9 to 6.0 ng toxic equivalence (TEQ)/dry standard cubic meter. The relative accuracies
achieved by DMS, AMESA, and jet-REMPI varied from 22.6% to 78.2%, with 100% data completeness. The RIMMPA-TOFMS produced no
quantifiable results due to various difficulties associated with the instrument during the testing. The two long-term samplers
were easy to install and operate and provided a cumulative, averaged emission for the sampling period. The operations of the
two semi-real-time continuous monitors were relatively complex, but one of them provided on-site, real-time data for PCDD/F
emissions from measurement of a TEQ correlative indicator compound. This article summarizes results from the individual Environmental
Technology Verification reports for the four dioxin monitors.
This work was presented, in part, at the Fourth International Conference on Combustion, Incineration/Pyrolysis and Emission
Control (i-CIPEC) 相似文献
967.
The monitoring of the odor annoyance generated by a landfill area is difficult, since it is a multi-area-sources problem, with a discontinuous odor emission. This paper proposes an adaptation of the method of sniffing team campaigns to the particular case of fresh waste odors. The method is based on the field determination of odor perception points, followed by data processing with a bi-Gaussian-type model, adapted to handle the odors. In a first step, field observers delineate the region in which odor impact is experienced and then the emission rate is manipulated in a dispersion model until the predicted size of the impact zone matches that observed in the field. In a second step the adjusted emission rate is entered into the model to calculate the percentiles corresponding to the average annoyance zone. The originality of the proposed method is the introduction of all observation points and of all recorded meteorological data into the model. The paper discusses the method limitations and the errors induced on the results, i.e. the odor emission rate and the percentile lines (or iso-concentration lines) which are used to describe the odor concentrations on a map of the surroundings of the plant. The proposed method proves to be reliable for diffuse sources, such as landfill areas. The obtained results are coherent with other results found in the literature with other techniques. 相似文献
968.
P. G. Bradley 《Resources Policy》1987,13(4)
The petroleum industry has traditionally generated substantial revenues for governments. Where governmental power is divided, as in federations like Canada and Australia, a junior level of government normally collects royalties while the senior level levies a variety of imposts (income tax, export duties, excises on production). The combination of recent sharp reductions in prices, more price volatility and an era of freer markets has subjected existing tax and royalty systems to severe strain and has shifted attention to the design of fiscal systems that are more profit- sensitive. For the royalty element, interest focuses on net value royalties (NVRs). This paper deals with the nature and problems of NVRs. It proceeds by looking first at the application of resource rent royalties in Australia. It then focuses on recent megaproject royalty arrangements in Alberta and evaluates the degree to which Alberta's current royalty system is profit- sensitive. Problems associated with NVRs are discussed in the fourth section; concluding remarks are made in the last section. 相似文献
969.
C. Stoate A. Bldi P. Beja N.D. Boatman I. Herzon A. van Doorn G.R. de Snoo L. Rakosy C. Ramwell 《Journal of environmental management》2009,91(1):22-46
The impacts of agricultural land use are far-reaching and extend to areas outside production. This paper provides an overview of the ecological status of agricultural systems across the European Union in the light of recent policy changes. It builds on the previous review of 2001 devoted to the impacts of agricultural intensification in Western Europe. The focus countries are the UK, The Netherlands, Boreal and Baltic countries, Portugal, Hungary and Romania, representing a geographical spread across Europe, but additional reference is made to other countries. Despite many adjustments to agricultural policy, intensification of production in some regions and concurrent abandonment in others remain the major threat to the ecology of agro-ecosystems impairing the state of soil, water and air and reducing biological diversity in agricultural landscapes. The impacts also extend to surrounding terrestrial and aquatic systems through water and aerial contamination and development of agricultural infrastructures (e.g. dams and irrigation channels). Improvements are also documented regionally, such as successful support of farmland species, and improved condition of watercourses and landscapes. This was attributed to agricultural policy targeted at the environment, improved environmental legislation, and new market opportunities. Research into ecosystem services associated with agriculture may provide further pressure to develop policy that is targeted at their continuous provisioning, fostering motivation of land managers to continue to protect and enhance them. 相似文献
970.
Picazo-Tadeo AJ Gómez-Limón JA Reig-Martínez E 《Journal of environmental management》2011,92(4):1154-1164
This paper assesses farming eco-efficiency using Data Envelopment Analysis (DEA) techniques. Eco-efficiency scores at both farm and environmental pressure-specific levels are computed for a sample of Spanish farmers operating in the rain-fed agricultural system of Campos County. The determinants of eco-efficiency are then studied using truncated regression and bootstrapping techniques. We contribute to previous literature in this field of research by including information on slacks in the assessment of the potential environmental pressure reductions in a DEA framework. Our results reveal that farmers are quite eco-inefficient, with very few differences emerging among specific environmental pressures. Moreover, eco-inefficiency is closely related to technical inefficiencies in the management of inputs. Regarding the determinants of eco-efficiency, farmers benefiting from agri-environmental programs as well as those with university education are found to be more eco-efficient. Concerning the policy implications of these results, public expenditure in agricultural extension and farmer training could be of some help to promote integration between farming and the environment. Furthermore, Common Agricultural Policy agri-environmental programs are an effective policy to improve eco-efficiency, although some doubts arise regarding their cost-benefit balance. 相似文献