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1.
2.
This article is a review of new and versatile optical-immunoassay instrumentation for water monitoring developed through two European Union projects, RIver ANAlyser (RIANA) and Automated Water Analyser Computer Supported System (AWACSS). Both projects utilise immunoassay techniques to isolate the analytes and Total Internal Reflection Fluorescence (TIRF) to quantify them. Completed in 1999, the RIANA project developed a sensitive and cost-effective analytical system capable of simultaneous detection of multiple-analytes in real-world water samples. The AWACSS project has been in progress since 2001 and is developing rugged-but-sensitive instrumentation that will detect up to 30 analytes simultaneously, will operate unattended, and will have networking capability.  相似文献   

3.
环境微生态研究中的分子生物学新技术   总被引:7,自引:0,他引:7  
随着分子生物学的发展,可用于环境微生态研究的新方法新手段不断出现.利用这些分子生物学技术,可直接对环境样品的总DNA进行分析,绕开菌株分离和培养瓶颈,可以最大限度地获得相关微生物的遗传信息,全面地分析环境中微生物的多样性.对目前广泛应用于环境微生态研究的分子生物学新技术,包括rDNA基因序列分析、变性梯度凝胶电泳、温度梯度凝胶电泳、单链构象多态性、限制性片段长度多态性、随机扩增多态性DNA、核酸杂交和DNA芯片等技术进行了综述.  相似文献   

4.
During the last decade, nanofiltration (NF) made a breakthrough in drinking water production for the removal of pollutants. The combination of new standards for drinking water quality and the steady improvement of the nanofiltration process have led to new insights, possible applications and new projects on lab-scale, pilot scale and industrial scale. This paper offers an overview of the applications in the drinking water industry that have already been realised or that are suggested on the basis of lab-scale research. Applications can be found in the treatment of surface water as well as groundwater. The possibility of using NF for the removal of hardness, natural organic material (NOM), micropollutants such as pesticides and VOCs, viruses and bacteria, salinity, nitrates, and arsenic will be discussed. Some of these applications have proven to be reliable and can be considered as known techniques; other applications are still studied on laboratory scale. Modelling is difficult due to effects of fouling and interaction between different components. The current insight in the separation mechanisms will be briefly discussed.  相似文献   

5.
主要介绍了含MTBE废水处理的工艺进展以及一些新方法、技术在实验以及生产实践中的应用 ,如氧化、气提、吸收、降解和自然衰减等 ,同时对各种方法的优缺点进行了评述 ,对未来的工艺进步做了展望  相似文献   

6.
The objective of this review was to synthesize existing information regarding the effects of petroleum hydrocarbons on marsh macrophytes in a manner that will help guide research and improve spill-response efficiency. Petroleum hydrocarbons affect plants chemically and physically. Although plants sometime survive fouling by producing new leaves, even relatively non-toxic oils can stress or kill plants if oil physically prevents plant gas-exchange. Plant sensitivity to fouling varies among species and among populations within a species, age of the plant, and season of spill. Physical disturbance and compaction of vegetation and soil associated with clean-up activities following an oil spill appear to have detrimental effects on the US Gulf coast marshes. Other techniques, including the use of chemicals such as cleaners or bioremediation, may be necessary to address the problem. Clean-up may also be beneficial when timely removal prevents oil from migrating to more sensitive habitats.  相似文献   

7.
Urbanization has appropriated millions of hectares of cropland, and this trend will persist as cities continue to expand. We estimate the impact of this conversion as the amount of land needed elsewhere to give the same yield potential as determined by differences in climate and soil properties. Robust spatial upscaling techniques, well-validated crop simulation models, and soil, climate, and cropping system databases are employed with a focus on populous countries with high rates of land conversion. We find that converted cropland is 30–40% more productive than new cropland, which means that projection of food production potential must account for expected cropland loss to urbanization. Policies that protect existing farmland from urbanization would help relieve pressure on expansion of agriculture into natural ecosystems.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01674-z.  相似文献   

8.
Biomonitoring, among other purposes, can be used as a tool to study the dispersion of trace elements through the atmosphere and back to the earth's surface again. In this sense it has been used for more than 20 years now. Yet, the calibration of biomonitors elemental contents against other atmospheric element dispersion variables like deposition or airborne concentration is still an open subject. The knowledge of a calibration nevertheless represents a qualitative improvement upon the use of biomonitors. Biomonitors elemental contents are usually assumed to depend in a linear way on the average values of atmospheric element dispersion variables, thus a linear regression is assumed to provide a good calibration. In this work: the element dispersion variables like deposition or airborne concentration will be referred in general as availability variables due to reasons that will be clarified; an uptake experiment using transplants of lichen Parmelia sulcata carried out in Portugal during a 2-year period (1994/1996) is described; and new concepts and calibration methods are presented. Lichen and aerosol samples were analysed by nuclear analytical techniques PIXE and INAA, and total deposition dry residue samples were analysed by ICP-MS. A database of roughly 70,000 values was thus created and biomonitor calibration carried out considering that biomonitors are not mechanical instruments but that they rather describe their exposure with a non-perfect memory. Data shows that surveying lichens four times within 1 year, with a period of 3 months in between sampling campaigns, allows the recovery of availability mean, maxima and standard deviation for many elements.  相似文献   

9.
The conventional uses of geographic information systems (GIS) in environmental management have been criticized for being undemocratic and avoiding the social dimension of these issues. To address these criticisms, new participatory approaches are being developed by the GIS community. These new techniques involve the integration of conventional spatial data and mental maps showing communities' (or various groups') perceptions of their environment and how they use resources. Case studies using these new techniques highlight how GIS is being incorporated into participatory studies. The advantages and drawbacks of using GIS for participation are discussed, with the conclusion that the techniques provide a useful new approach for environmental management.  相似文献   

10.
染料废水处理技术的研究与进展   总被引:3,自引:0,他引:3  
概述了含染料废水处理方法的研究现状和最新进展 ,尤其是在物化法 (包括辐射法、吸附 萃取法、磁分离法、混凝沉降法和氧化法 )、生物法 (好氧 厌氧氧化 -还原序列反应器、固定化微生物降解、膜生物反应器 )及生物 -物化联合法 (生物吸附剂、生物活性炭、厌氧折流板反应池 -生物接触氧化池 -混凝沉淀 -砂滤池处理工艺、水解酸化 -接触氧化法等 )中的新技术的研究现状 ,新方法、材料、工艺的应用方面 ,对提高此类废水的处理效果有重要的理论和实际意义  相似文献   

11.
Wang S  Li H  Xie S  Liu S  Xu L 《Chemosphere》2006,65(1):82-87
Natural zeolite and synthetic zeolite, MCM-22, were employed as effective adsorbents for a basic dye, methylene blue, removal from wastewater. Two methods, Fenton oxidation and high temperature combustion, have been used for regeneration of used materials. It is found that MCM-22 exhibits equilibrium adsorption at 1.7 x 10(-4) mol g(-1), much higher than the adsorption of natural zeolite (5 x 10(-5) mol g(-1)) at initial dye concentration of 2.7 x 10(-5)M and 30 degrees C. Solution pH will affect the adsorption behaviour of MCM-22. Higher solution pH results in higher adsorption capacity. The regenerated adsorbents show different capacity depending on regeneration technique. Physical regeneration by high temperature combustion will be better than chemical regeneration using Fenton oxidation in producing effective adsorbents. Regeneration of MCM-22 by high temperature treatment can make the adsorbent exhibit comparable or superior adsorption capacity as compared to the fresh sample depending on the temperature and time. The optimal temperature and time will be 540 degrees C and 1h. The Fenton oxidation will recover 60% adsorption capacity. For natural zeolite, regeneration can not fully recover the adsorption capacity with the two techniques and the regenerated natural zeolites by the two techniques are similar, showing 60% adsorption capacity of fresh sample. Kinetic studies indicate that the adsorption follows pseudo-second-order kinetics.  相似文献   

12.
The emissions factor modeling component of the motor vehicle emissions inventory (MVEI) modeling suite is currently being revised by the California Air Resources Board (CARB). One of the proposed changes in modeling philosophy is a shift from using link-based travel activity data to trip-based travel data for preparing mobile emissions inventories. Also as part of the revisions, new speed correction factors (SCFs) will be developed by CARB for the revised model. The new SCFs will be derived from vehicle emissions on 15 new driving cycles, each constructed to represent a typical trip at a specific average speed. This paper discusses how the new SCFs will affect transportation conformity and emissions inventory development, and evaluates the differences in total emissions produced by trip-based and link-based distributions of speed and vehicle miles of travel (VMT). We simulated both link-based and trip-based speed-VMT distributions using travel data from the Sacramento and San Diego travel demand models. On the basis of the simulation results, there is reason to expect that mobile emissions inventories constructed using the proposed trip-based philosophy will differ markedly from those constructed in the current manner. Noting that results may vary by region, increases are expected in the CO and HC inventory levels, with concomitant decreases in the NOx mobile emissions inventories.  相似文献   

13.
In Mexican waters, there is no a formal and well-established monitoring program of harmful algal blooms (HAB) events. Until now, most of the work has been focused on the characterization of organisms present in certain communities. Therefore, the development of new techniques for the rapid detection of HAB species is necessary. Capillary electrophoresis finger print technique (CE-SSCP) is a fingerprinting technique based on the identification of different conformers dependent of its base composition. This technique, coupled with capillary electrophoresis, has been used to compare and identify different conformers. The aim of this study was to determine if CE-SSCP analysis of ribosomal RNA (rRNA) gene fragments could be used for a rapid identification of toxic and harmful HAB species to improve monitoring activities along the coasts of Baja California Sur, Mexico.Three different highly variable regions of the 18S and 28S rRNA genes were chosen and their suitability for the discrimination of different dinoflagellate species was assessed by CE-SSCP.The CE-SSCP results obtained for the LSU D7 fragment has demonstrated that this technique with this gene region could be useful for the identification of the ten dinoflagellates species of different genera.We have shown that this method can be used to discriminate species and the next step will be to apply it to natural samples to achieve our goal of molecular monitoring for toxic algae in Mexican waters. This strategy will offer an option to improve an early warning system of HAB events for coastal BCS, allowing the possible implementation of mitigation strategies. A monitoring program of HAB species using molecular methods will permit the analysis of several samples in a short period of time, without the pressure of counting with a taxonomic expert in phytoplankton taxonomy.  相似文献   

14.
城市缓流水体因其受城市发展的影响大、自身流动性小和自净能力弱的特点 ,正处于被人为破坏而面临消失之中。而生物净化技术是根据水体自净的原理而设计和开发的污染水体净化技术。本文列举了国内外城市污染水体常用的生物净化技术的特点及应用情况 ,指出了各种生物净化技术在实际应用中的不足和发展前景 ,为我国城市水体的治理提供参考  相似文献   

15.
ABSTRACT

The emissions factor modeling component of the motor vehicle emissions inventory (MVEI) modeling suite is currently being revised by the California Air Resources Board (CARB). One of the proposed changes in modeling philosophy is a shift from using link-based travel activity data to trip-based travel data for preparing mobile emissions inventories. Also as part of the revisions, new speed correction factors (SCFs) will be developed by CARB for the revised model. The new SCFs will be derived from vehicle emissions on 15 new driving cycles, each constructed to represent a typical trip at a specific average speed. This paper discusses how the new SCFs will affect transportation conformity and emissions inventory development, and evaluates the differences in total emissions produced by trip-based and link-based distributions of speed and vehicle miles of travel (VMT).

We simulated both link-based and trip-based speed-VMT distributions using travel data from the Sacramento and San Diego travel demand models. On the basis of the simulation results, there is reason to expect that mobile emissions inventories constructed using the proposed trip-based philosophy will differ markedly from those constructed in the current manner. Noting that results may vary by region, increases are expected in the CO and HC inventory levels, with concomitant decreases in the NOx mobile emissions inventories.  相似文献   

16.
Groundwater and sub-surface contamination by Light Non-Aqueous Phase Liquids (LNAPLs) is one of the industrial world's most pressing environmental issues and a thorough understanding of the hydrological, physical and bio-chemical properties of the sub-surface is key to determining the spatial and temporal development of any particular contamination event. Non-invasive geophysical techniques (such as electrical resistivity, electromagnetic conductivity, Ground-Penetrating Radar, etc.) have proved to be successful sub-surface investigation and characterisation tools with Ground-Penetrating Radar (GPR) being particularly popular. Recent studies have shown that the spatial/temporal variation in GPR signal attenuation can provide important information on the electrical properties of the sub-surface materials that, in turn, can be used to assess the physical and hydrological nature of the pore fluids and associated contaminants. Unfortunately, a high percentage of current LNAPL-related GPR studies focus on contaminant mapping only, with little emphasis being placed on characterising the hydrological properties (e.g., determining contaminant saturation index, etc.). By comparing laboratory-based, dielectric measurements of LNAPL contaminated materials with the GPR signal attenuation observed in both contaminated and 'clean' areas of an LNAPL contaminated site, new insights have been gained into the nature of contaminant distribution/saturation and the likely signal attenuation mechanisms. The results show that, despite some practical limitations of the analysis technique, meaningful hydrological interpretations can be obtained on the contaminant properties, saturation index and bio-degradation processes. A generalised attenuation/saturation model has been developed that describes the physical and attenuation enhancement characteristics of the contaminated areas and reveals that the most significant attenuation is related to smeared zone surrounding the seasonally changing water table interface. It is envisaged that the model will provide a basis for the interpretation of GPR data from analogous LNAPL contaminated sites and provide investigators with an appreciation of the merits and limitations of GPR-based, attenuation analysis techniques for hydrological applications.  相似文献   

17.
Air pollution in the industrialised world has in the last 50 years undergone drastic changes. Until after World War II the most important urban compound was sulphur dioxide combined with soot from the use of fossil fuels in heat and power production. When that problem was partly solved by cleaner fuels, higher stacks and flue gas cleaning in urban areas, the growing traffic gave rise to nitrogen oxides and volatile organic compounds and in some areas photochemical air pollution, which may be abated by catalytic converters. Lately the interest has centred on small particles and more exotic organic compounds that can be detected with new sophisticated analytical techniques.Simultaneously with the development in compounds, the time and geographical scale of interest have increased. First to transboundary air pollution, which in decades and on continents can degrade ecosystems, later to the depletion of the ozone layer and especially to the increasing greenhouse effect with climate change that will change the conditions for nature and mankind on the entire globe. The possibilities to study these large scale phenomena have been greatly enhanced by the development of electronic computers that can handle large data sets and calculate various scenarios.All these processes take place in the thin layer of gases around the Earth, the atmosphere. Although the abatement is often restricted to a single aspect, they are often connected and should when possible be treated as whole.  相似文献   

18.
An assessment has been made of the state of emission measurement technology to determine whether measurement techniques are sufficiently well advanced to support the development of emission control methods and the implementation of emission standards for aircraft engines. The conclusion drawn from this assessment is that current measurement technology will meet most of the requirements of an emission control program. Certain measurement techniques are inadequate at present but development of improved techniques appears to be proceeding at a satisfactory rate.  相似文献   

19.
The use of synthetic pesticides has become an indispensable tool in agriculture for the control of pests. Therefore, the search for remedies and techniques for decontamination and detoxification of a pesticide-contaminated environment has become an important part of the research. Currently, bioremediation seems to be one of the most environmentally safe and cost-effective methods. In nature, the existence of abundant material resources can be used to degrade the environmental pesticide pollutants. At present, a number of microorganisms, capable of degrading pesticides, have been isolated and characterised. For insects, insecticide resistance-associated esterases have been purified and characterised from several insect species, and a new family of cytochrome P450 apparently associated with insecticide resistance in the tobacco budworm, was discovered. Generally, two bioremediation approaches have been used one directly based on microorganisms, and the other involved in isolated enzymes. For the former, in addition to using natural microorganism strains, with genetic techniques certain desirable biodegradation pathways from different organisms are brought together in a single host. However, because of their own limits, especially problems associated with releasing genetically altered microorganisms into the environment, the strategy based on enzymes seems more feasible. In the long term, collaborations between microbiologists, biochemists, and engineers will become increasingly important to efficiently dispose of the pesticide pollutants.  相似文献   

20.
While the new source emission offset provision contained in recent acid rain proposals would result in increasing utility costs over time, the demand for emission offsets from new powerplant units should be satisfied even under conditions of high future growth in electrical generating capacity. This is because the amount of emissions from new generating units will be small relative to the quantity of offsets that could be made available in the emission “allowance” market.

Under the President’s July 1989 proposal, most utilities would be able to reduce their emissions well below their allowance levels via fuel switching, the installation of control technology, or the use of other emission reduction techniques, in order to create more “headroom” for the construction of new generating units. Retirements and decreasing utilization of existing power plants over time would liberate other emission allowances for use by new units. Industrial sources could “opt in” to the acid rain program and provide allowances for new generating units as well. A number of provisions in the recently passed Senate and House bills would make still further sources of allowances available to offset emissions from new generating capacity.

Hoarding of allowances by utilities is unlikely to be a problem since allowances would be distributed to at least 88 utilities in 34 states, and many of these utilities would have the ability to cost-effectively free up more allowances through “overcontrol” than they would need to cover their own future growth. Even a relatively small number of utilities in a limited number of states would have the ability to supply all of the allowances needed to cover new capacity growth from those entities that could not otherwise provide their own offsets. At projected prices of up to $800/ton, the incentives for utilities to sell allowances would be considerable. Moreover, if hoarding did begin to occur, the price of allowances would respond by rising to higher levels and the incentives for utilities to sell allowances would become even more compelling, as greater opportunities would develop for reducing costs (and electricity rates).  相似文献   

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