在能源结构及利用中减少SO_2及NO_x排放量的对策

1.前言有几种削减有害废物排放量的重要途径。A代表所有的一次能源E中某种化合物的总体排放量 A=∑E×C×R (1) 式中C是燃烧单位能源量的化合物生成量,R是净化设备产生的削减因子,另外, E=∑a×ex效率 (2) 式中a表示活动水平,e是指a在每个部门中的单位最终能源,效率是指把一次能源转化成适合于使用的最终形式的效率。∑(总和)则包括社会上全部活动之和。当然,公式通过每个领域的平均值将现实生活简化了。排放量能受到上述公式中的任何     

Metal distribution in incineration residues of municipal solid waste (MSW) in Japan

This study aimed to identify distribution of metals and the influential factors on metal concentrations in incineration residues. Bottom ash and fly ash were sampled from 19 stoker and seven fluidized bed incinerators, which were selected to have a variety of furnace capacity, furnace temperature, and input waste. In the results, shredded bulky waste in input waste increased the concentration of some metals, such as Cd and Pb, and the effect was confirmed by analysis of shredded bulky waste. During MSW incineration, lithophilic metals such as Fe, Cu, Cr, and Al remained mainly in the bottom ash while Cd volatilized from the furnace and condensed to the fly ash. About two thirds of Pb and Zn was found in the bottom ash despite their high volatility. Finally, based on the results obtained in this study, the amount of metal in incineration residues of MSW was calculated and the loss of metal was estimated in terms of mass and money. A considerable amount of metal was found to be lost as waste material by landfilling of incineration residues.     

Sorption of sulfonamide pharmaceutical antibiotics on whole soils and particle-size fractions

Residues of pharmaceutical antibiotics are found in the environment, whose fate and effects are governed by sorption. Thus, the extent and mechanisms of the soil sorption of p-aminobenzoic acid and five sulfonamide antibiotics (sulfanilamide, sulfadimidine, sulfadiazine, sulfadimethoxine, and sulfapyridine) were investigated using topsoils of fertilized and unfertilized Chernozem and their organic-mineral particle-size fractions. Freundlich adsorption coefficients (K(f)) ranged from 0.5 to 6.5. Adsorption increased with aromaticity and electronegativity of functional groups attached to the sulfonyl-phenylamine core. Adsorption to soil and particle-size fractions increased in the sequence: coarse silt < whole soil < medium silt < sand < clay < fine silt and was influenced by pH. Sorption nonlinearity (1/n 相似文献   

Influence of sea salts on drainage water and soil chemistry of two different soil types: soil leaching experiments under laboratory conditions

The effects of sea-salt on drainage water and soil chemistry was studied using two different soil types and setting up five soil-leaching experiments under controlled laboratory conditions. The objectives of the soil-leaching experiments were to provide information of the variability of soils and their drainage water chemistry following the input of different sea-salt solutions with different times which was similar to the precipitation input experienced during the storms in fields. Analyses were presented of major ions (Na+, Ca2+, Mg2+, Cl-, NO3-, SO4(2-) and NH4+) and pH for drainage water. At the end of the experiment, CEC (cation exchange capacity), %BS (percent base saturation), exchangeable capacity of Na, Ca and Mg and pH were also analysed for soil horizon chemistry. The results showed an increase in concentration of most of the major ions in the drainage water, though some adsorption of Na, Ca and Mg had taken place; so the result being a significant decrease in soil water pH. The chemical characteristics of each soil horizons also showed significant changes with the sea-salt applications compared to initial chemical characteristics. However, comparison of data from the four different sea-salt applications under different soil type or land-use didn't indicate the additional role that different land management could play in drainage water or soil chemistry.     

Rotational application of bioinsecticide with deltamethrin-An antilarval measure for the control of filarial vector, Culex quinquefasciatus (Culicidae: Diptera)

A laboratory investigation was undertaken to study the cyclic usage of field recommended doses of Bacillus thuringiensis israelensis (Bti), Bacillus sphaericus (Bsp) and combination of Bti and Bsp (half the recommended dose of each) with deltamethrin 2.8 EC to attain better control of mosquito larvae. To understand the susceptibility status of the Culex quinquefasciatus larvae in the field, early fourth instar field collected larvae were exposed to the above treatments of biopesticides and were monitored for their persistency till 50% mortality was obtained. The larvae those survived in each treatment were transferred to the concentration of deltamethrin that gave 50% mortality. Observations on larval mortality after the treatment with deltamethrin were recorded after 24 h. The results revealed that Bti excels Bsp, as it recorded 54% mortality only on 17th day after application. The other salient finding of this study is LC50 of deltamethrin is sufficient to follow the biopesticides application for an effective control of Culex larvae.     

Halogenated aromatics from steel production: results of a pilot-scale investigation

The potential environmental impact of emissions of halogenated aromatics from the steel industry is of growing concern. It has been suggested that electric arc furnaces are the only industrial source with constant or increasing emissions of dioxins to air. Here the results are reported from a pilot plant study on how scrap composition and various treatment alternatives affect the formation and release of chlorinated and brominated aromatics. The experiments were conducted with a statistical mixture design, and it is shown that scrap composition has a significant impact on the outcome. In contrast, the various treatment schemes examined--shredding, disassembly, and briquetting--did not affect the formation and release of halogenated aromatics. Parallel experiments with injection of adsorbents showed that it is possible to reduce emissions without substantial investments, and this option is recommended as a low-cost solution.     

Kinetics of Biotransformation of 2,4-Dichlorophenol using UASB-Reactor

Chlorophenol compounds are environmental pollutants that are both anthropogenic and xenobiotics. Some of these chemicals are carcinogens and are both toxic to a number biochemical processes. Biotransformation of 2,4-dichlorophenol (2,4-DCP) was studied in the presence of glucose on an upflow anaerobic sludge blanket reactor (UASB) using mixed culture. A continuously operated UASB reactor was employed using mixed synthetic wastewater. Results obtained from the 1.8 L volume capacity UASB reactor were subjected to kinetic evaluation constants. Results indicate that the degradation of 2,4-DCP in the presence of glucose was strongly influenced by the concentration of the compound. High degradation levels were observed when the concentration of 2,4-DCP was in the range of 50-150 mg L(-1). Concentrations of 2,4-DCP above 160 mg L(-1) were toxic to microbes even in the presence of glucose. The maximum degradation of 2,4-DCP was found to be 70.4% when initial concentration of 2,4-DCP was 124 mg L(-1) and glucose concentration of 500 mg L(-1) at hydraulic retention time of 13.2 hr. The biodegradation followed first order reaction kinetics with a rate constant (K) of 0.67, Vmax of 0.244 kg m(-3) day(-1), Ks of 0.117 kg m(-3) day(-1) and correlation coefficient of 0.766.     

Uncertainties and recommendations

An assessment of the impacts of changes in climate and UV-B radiation on Arctic terrestrial ecosystems, made within the Arctic Climate Impacts Assessment (ACIA), highlighted the profound implications of projected warming in particular for future ecosystem services, biodiversity and feedbacks to climate. However, although our current understanding of ecological processes and changes driven by climate and UV-B is strong in some geographical areas and in some disciplines, it is weak in others. Even though recently the strength of our predictions has increased dramatically with increased research effort in the Arctic and the introduction of new technologies, our current understanding is still constrained by various uncertainties. The assessment is based on a range of approaches that each have uncertainties, and on data sets that are often far from complete. Uncertainties arise from methodologies and conceptual frameworks, from unpredictable surprises, from lack of validation of models, and from the use of particular scenarios, rather than predictions, of future greenhouse gas emissions and climates. Recommendations to reduce the uncertainties are wide-ranging and relate to all disciplines within the assessment. However, a repeated theme is the critical importance of achieving an adequate spatial and long-term coverage of experiments, observations and monitoring of environmental changes and their impacts throughout the sparsely populated and remote region that is the Arctic.     

Seasonal variability of 1-chloropyrene on atmospheric particles and photostability in toluene

The occurrence of a mutagenic compound, 1-chloropyrene (Cl-Py), in extracts of ambient particulate matter at an urban site in Japan has been investigated. Samples were collected with a high-volume air sampler for 24 h periods over the course of 1 week in winter (February), spring (May), summer (August), and autumn (November) 2002. The Cl-Py levels showed seasonal variation, ranging from 2.4 pg/m(3) (summer) to 18.9 pg/m(3) (winter). This variation would indicate that the lower temperatures in winter results in an increased distribution of Cl-Py from vapor phase to the particle phase. In addition, there is also the possibility that ambient Cl-Py is emitted from seasonal sources or is susceptible to photodegradation by sunlight, or both. The photodegradation of Cl-Py in a laboratory experiment was conducted to simulate the compound's fate on airborne particle surfaces. The degradation of Cl-Py proceeded by a first-order reaction with a rate constant of 0.72 h(-1). In the presence of a radical sensitizer, 9,10-anthraquinone (AQ), the photodegradation rate of Cl-Py was elevated in comparison with the rate in the absence of AQ. In addition, the dechlorination of Cl-Py (i.e., the formation of Py) occurred in the presence of AQ.     

The composting potential of different organic solid wastes: experience from the island of Crete

For the past 20 years, the National Foundation for Agricultural Research in Crete and the School of Agricultural Technology of the Technological and Educational Institute of Crete have been involved in a number of research and development activities, related to the production and evaluation of compost derived from a variety of local solid, mainly agricultural organic wastes. Materials such as olive press cake, olive tree leaves (OTL) and branches, vine branches (VB), pressed grape skins (PGS), pig manure (PM), sewage sludge and the organic fraction of municipal solid waste (OFMSW) have been evaluated for their behaviour during composting, their compatibility in mixtures and the quality of the end product. The quality evaluation included both a detailed physiochemical (pH, electrical conductivity (EC), nutrients concentration, heavy metal concentration, etc.) and biological analyses (pathogenic microorganisms). It also included an agronomic evaluation, in which composts were used either as a soil amendment or as a component for substrates in open air or covered (greenhouse) cultivation mainly of local vegetables (tomatoes, cucumbers, etc.). All materials were composted successfully, especially when mixed. The end products contained large amounts of organic matter, usually combined with an increased EC value. Pressed grape skins should be considered as the ideal raw material, producing a high quality compost, with the lowest EC value (1.57 mS cm(-1)) and the largest organic matter concentration (84.50%), compared to all other materials. When any of the produced compost was used in a ratio of 30% by volume (v/v), it increased plant growth, whereas in larger volumes, it presented phytotoxic behaviour, inhibiting both root and shoot development.