有限单元法及其在河流污染计算中的应用

介绍了应用有限单元法预测计算河道较平直，水流稳定河流中污染物浓度分布的二维平面数学模型，该模型具有应用方便，计算迅捷等优点，计算中无须先知道排放口污染物掺混浓度，能直观地反映有多个排放口的河流中的污染物浓度分布的情况。     

SBR技术的发展及应用

综述了SBR基本运行原理及工艺特点，着重对SBR各种工艺形式的结构、特点进行了分析和评价，并对其研究和应用现状进行了介绍，认为具有脱氮除磷功能的新型SBR的研究，将成为污水处理领域的新热点。     

ASM3模型研究与运用

根据国际水质协会推出的ASM3利用MATLAB建立模型,通过实验确定进水水质及模型初值,通过模拟结果与污水处理厂实测结果对比,确定重要模型参数范围,并用结果对其他污水处理厂进行模拟,模拟结果与实测结果吻合较好.     

Development of a livestock odor dispersion model: part I. Model theory and development

A livestock odor dispersion model (LODM) was developed to predict mean odor concentration, odor frequency, instantaneous odor concentration, and peak odor concentration from livestock operations. This model is based on the Gaussian fluctuating plume model and has the ability to consider the instantaneous concentration fluctuations and the differences between odor and traditional air pollutants. It can predict odor frequency from the routine hourly meteorological data input and deal with different types of sources and multiple sources. Also, the relationship between odor intensity and odor concentration was incorporated into the model.     

Application of a Three-Layer Photochemical Box Model in an Athens Street Canyon

ABSTRACT

The aim of this paper is to show that a photochemical box model could describe the air pollution diurnal profiles within a typical street canyon in the city of Athens. As sophisticated three-dimensional dispersion models are computationally expensive and they cannot serve to simulate pollution levels in the scale of an urban street canyon, a suitably modified three-layer photochemical box model was applied. A street canyon of Athens with heavy traffic was chosen to apply the aforementioned model. The model was used to calculate pollutant concentrations during two days with meteorological conditions favoring pollutant accumulation. Road traffic emissions were calculated based on existing traffic load measurements. Meteorological data, as well as various pollutant concentrations, in order to compare with the model results, were provided by available measurements. The calculated concentrations were found to be in good agreement with measured concentration levels and show that, when traffic load and traffic composition data are available, this model can be used to predict pollution episodes. It is noteworthy that high concentrations persisted, even after additional traffic restriction measures were taken on the second day because of the high pollution levels.     

Development and Preliminary Evaluation of a Particulate Matter Emission Factor Model for European Motor Vehicles

ABSTRACT

Although modeling of gaseous emissions from motor vehicles is now quite advanced, prediction of particulate emissions is still at an unsophisticated stage. Emission factors for gasoline vehicles are not reliably available, since gasoline vehicles are not included in the European Union (EU) emission test procedure. Regarding diesel vehicles, emission factors are available for different driving cycles but give little information about change of emissions with speed or engine load. We have developed size-specific speed-dependent emission factors for gasoline and diesel vehicles. Other vehicle-generated emission factors are also considered and the empirical equation for re-entrained road dust is modified to include humidity effects. A methodology is proposed to calculate modal (accelerating, cruising, or idling) emission factors. The emission factors cover particle size ranges up to 10 um, either from published data or from user-defined size distributions.

A particulate matter emission factor model (PMFAC), which incorporates virtually all the available information on particulate emissions for European motor vehicles, has been developed. PMFAC calculates the emission factors for five particle size ranges [i.e., total suspended particulates (TSP), PM₁₀, PM₅, PM₂₅, and PM₁] from both vehicle exhaust and nonexhaust emissions, such as tire wear, brake wear, and re-entrained road dust. The model can be used for an unlimited number of roads and lanes, and to calculate emission factors near an intersection in user-defined elements of the lane. PMFAC can be used for a variety of fleet structures. Hot emission factors at the user-defined speed can be calculated for individual vehicles, along with relative cold-to-hot emission factors. The model accounts for the proportions of distance driven with cold engines as a function of ambient temperature and road type (i.e., urban, rural, or motorway).

A preliminary evaluation of PMFAC with an available dispersion model to predict the airborne concentration in the urban environment is presented. The trial was on the A6 trunk road where it passes through Loughborough, a medium-size town in the English East Midlands. This evaluation for TSP and PM₁₀ was carried out for a range of traffic fleet compositions, speeds, and meteorological conditions. Given the limited basis of the evaluation, encouraging agreement was shown between predicted and measured concentrations.     

曝气生物滤池的特点、应用及发展

曝气生物滤池是近年来国内外发展较快的一种废水好氧生物处理新工艺,该工艺具有处理能力强、处理效果好、不需二沉池等优点.文中综述了曝气生物滤池的工艺原理、特点及其在污水处理中的应用和发展.     

循环经济村发展模式研究

运用循环经济学原理和系统工程方法,对一个行政村的社会经济发展和生态建设进行总体规划设计,科学安排农、工、商、建、运和农业系统内部的农、林、牧、渔、副的发展比例,不断提高社会生产力和自然生产力,实现可持续发展,推动社会进步,为全面实现小康社会奠定基础.     

Application of a Chemical Mass Balance Receptor Model to Respirable Particulate Matter in Mexico City

Mexico City frequently experiences high levels of air pollution. This is due mainly to its topography and meteorology that suppress pollutant diffusion and dispersion. The atmospheric mixing is extremely poor, especially during the dry winter months. The levels of certain pollutants, such as particulate matter, are of concern since they have severe effects on public health. Visibility deterioration is one of the most noticeable effects in large cities. Biological effects of particulate matter on man and animals, ranging from mild eye irritation to death, have been reported. The effects depend on the size of the particles, their solubility, and toxicity. The main objective of this paper is to present the results of a chemical mass balance receptor model applied to a well-characterized data set of particulate matter collected in the Mexico City Metropolitan Area (MCMA). Samples of particulate matter were collected using a denuder and a Hi-Vol system for the respi-rable fraction and total suspended particles, respectively. In this paper the analysis of a database consisting of the chemical composition of 33 samples of respirable particulate matter (aerosols with diameter less than 2.5 µm) is presented. The 12-hour samples were acquired during day and night periods in a typical medium-income neighborhood from December 19, 1989 through February 5, 1990.     

Carbon Monoxide in an Urban Environment: Application of a Receptor Model for Source Apportionment

During the winter of 1985-86 the authors took 6-h integrated air samples and measured the concentrations of carbon monoxide and other gases at a residential site in Olympia, Washington. The 6-h average concentrations were between about 0.2 and 3.2 ppmv. For each 6-h period the observed concentration of CO was apportioned among its sources which were residential wood burning and automobiles. Small and generally insignificant amounts of CO were also observed from unidentified sources. A chemical mass balance (CMB) was formulated and applied to apportion the observed CO among its sources. Methylchloride (CH₃CI), in excess of background levels, was used as a unique tracer of wood burning and excess hydrogen (H₂) served as a tracer of CO from automobiles. The source emission factors to carry out the calculations were estimated from other experiments. The results showed that in Olympia, wood burning can often contribute as much CO as automobiles during winter. The maximum 6-h average contribution of CO from wood burning was about 2 ppmv and from automobiles it was 2.2 ppmv, and the average ambient concentration was about 1 ppmv. When pollution from wood burning was present, it contributed 0.5 ppmv on average while automobiles also contributed 0.5 ppmv. Unidentified sources contributed 0.1 ppmv and the background level was 0.15 ppmv. During the winter many times wood burning did not affect CO concentrations, while CO from automobiles was always present. On average, during the winter, automobiles contributed some 50 percent of the CO mass to the lower urban atmosphere and wood burning contributed about 30 percent. Diurnal cycles became evident in the calculated concentrations of CO from wood burning and automobiles even though the measured concentrations did not show strong diurnal variations. Wood burning contributed most during evening and nighttime and very little during the day, while automobiles contributed most during the morning and evening hours and very little at night. These patterns lend support to the accuracy of the model and source emission factors since they are as expected from the diurnal variations of the sources and atmospheric mixing.     

Element accumulation performance of living and dead lichens in a large-scale transplant application

Environmental Science and Pollution Research - In bioaccumulation studies, sample devitalization through acid washing or oven drying is commonly applied to enhance the element accumulation...     

Application of a Chemical Mass Balance Receptor Model to Respirable Particulate Matter in Mexico City

Mexico City frequently experiences high levels of air pollution. This is due mainly to its topography and meteorology that suppress pollutant diffusion and dispersion. The atmospheric mixing is extremely poor, especially during the dry winter months. The levels of certain pollutants, such as particulate matter, are of concern since they have severe effects on public health. Visibility deterioration

is one of the most noticeable effects in large cities. Biological effects of particulate matter on man and animals, ranging from mild eye irritation to death, have been reported. The effects depend on the size of the particles, their solubility, and toxicity. The main objective of this paper is to present the results of a chemical mass balance receptor model applied to a well-characterized data set of particulate matter collected in the Mexico City Metropolitan Area (MCMA). Samples of particulate matter were collected using a denuder and a Hi-Vol system for the respirable fraction and total suspended particles, respectively.

In this paper the analysis of a database consisting of the chemical composition of 33 samples of respirable particulate matter (aerosols with diameter less than 2.5 μm) is presented. The 12-hour samples were acquired during day and night periods in a typical medium-income neighborhood from December 19, 1989 through February 5, 1990.

The results show that the main contributors to suspended particles are vehicles without catalytic converters and heavy-duty diesel vehicles. The contribution of refineries, smelters, cement plants, resuspended dust, natural sources, and secondary aerosols were taken into account. In particular, the vehicles without catalytic converters represent the major contribution to PM2.5. They contribute with 50% during the day and 38% at night. Most of the source profiles were taken from the model library SPECIATE EPA. However, native profiles for soil, vehicles, and refinery were designed.     

膜生物反应器在污水处理中的应用现状及展望

综述了膜生物反应器（MBR）的研究进展，介绍了其分类及特点、处理机理与MBR运行的影响因素以及膜污染的控制等，并概括了MBR的发展及展望。MBR是近来发展较迅速的一种污水治理设备，具有占地少、能耗低等优点，但也存在一定的缺点，其中膜污染是影响其推广应用的主要因素，目前国内外学者一般都以膜污染作为切入点进行研究，通过改变料液性质、优化操作参数、提高膜清洗效率等方法得以防治膜污染。     

Development of a Dynamic Aquatic Model (DynA Model): Estimating Temporal Emissions of DDT to Lake Maggiore (N. Italy)

- DOI: http://dx.doi.org/10.1065/espr2006.01.009 Background, Aims and Scope Most existing models used to describe the fate of chemicals in surface water and sediment generally consider a 'static scenario', in which a contaminant is discharged at a constant rate and environmental input parameters do not change during the simulation time. This approach is not suitable in environmental scenarios characterized by daily or periodic changes of several input parameters. The aim of this study is to estimate approximate emissions of DDT lo Lake Maggiore using a new surface water model, (DynA Model) that describes the fate of a chemical in a dynamic scenario. Methods The model is developed on the grounds of an existing and validated model (QWASI). A numerical solution was adopted to build the fully dynamic version of the model. Results and Discussion The model was applied to Lake Maggiore emitting DDT at a constant rate until steady-state was reached. Emissions were stopped and later sporadic 'pulse' emissions were added. This was done to calculate the amount of DDT needed to simulate concentrations close to those measured in water and sediments. This allowed the evaluation of the order of magnitude of emissions. An uncertainty analysis for sediment resuspension was also performed, given the lack of measured resuspension rates. Conclusion The model showed the time response of the Lake Maggiore system to varying emission scenarios and provided what are regarded as reasonable estimates of DDT emissions. The model demonstrated the importance of sediment-water exchange. Recommendation and Outlook In order to better calculate DDT concentrations the model should be run with different discharge scenarios to clarify the time trends of concentrations, possibly with the use of different sets of measured data (such as biota and sediment deposition/resuspension rates).     

灰色模型在确定关键污染因子中的应用

将灰色模型引入水环境质量评价中，通过对某个时间段内污染物原始监测数据的灰色处理，从动态演变中找出关键因子，客观地判定各污染因子所起的作用，并对各因子在下一个时间段的发展趋势作出判断，增加了评价的准确性。经过实例运用分析表明，该方法物理意义明确，简便易用。     

MBR技术在废水处理中的研究现状及其展望

膜生物反应器(MBR)是将生物处理与膜分离技术相结合而成的一种新型、高效的废水处理工艺,因此对MBR的工艺组成、特征、存在的问题、发展进程及应用现状进行了阐述,并就其应用前景进行了分析评价.     

厌氧消化1号模型(ADMl)的发展及其应用

国际水协(IWA)于2002年正式推出了厌氧消化1号模型(ADM1),其主要目的是建立一个厌氧工艺建模和模拟的通用平台,促进厌氧处理工艺技术的发展.近年来,ADMI在许多方面得到扩展,如包含硫酸盐还原、硝酸盐还原、产气及其释放的扩展等,这使ADM1更趋于完善.ADM1与其他污水处理数学模型结合的应用以及在分布参数模型中的应用是当前该模型应用的主要方面.有机物发酵的复杂性以及数量众多的模型动力学参数和组分都极人限制了该模型的广泛应用.     

Metallic Element Composition of Particulate Matter During Day and Night Sampling at a Traffic Site

Day and night period sampling programs were carried out using a versatile air pollutant system to collect fine particulate matter (PM_2.5) and coarse particulate matter (PM_2.5–10) simultaneously at a traffic junction that is only 60 m from HungKuang University located in Central Taiwan. Therefore, HungKuang University is regarded as the traffic sampling site in this study. Similar measurements were carried out in a previous 2013 study by Fang and colleagues during October 2012 to November 2012. Determination of metallic element composition of fine and coarse particulates collected during the day and the night was accomplished with inductively coupled plasma atomic emission spectrometry (ICP-AES). The results indicated that there were no significant differences in composition of metallic elements Zn, Cu, Cr, Mn, Fe, Pb, and Cd in either coarse or fine particles for both day and night sampling periods. The statistical results indicated no significant differences for metallic elements in the PM_2.5–10 particulates for day and night sampling periods. Also, no significant differences were noted for metallic elements in the PM_2.5 particulates for day and night sampling periods at this traffic sampling site. The proposed reason is the limited sampling period employed in this study. Another potential reason is the presence of traffic that runs heavily both day and night being a major contributor to the ambient air metallic pollutants in this region.     

Development and Demonstration of an Explicit Lumped-Parameter Biofilter Model and Design Equation Incorporating Monod Kinetics

Abstract

Biofiltration is an economical air pollution control (APC) technology, particularly suitable for the treatment of air-streams having high flow rates and low concentrations of volatile organic compounds (VOCs). This technology utilizes enzymatic catalysis at ambient conditions to mineralize such pollutants to CO₂, H₂O, and salts. A pilot-scale study conducted for more than 4 years investigated the development of a new biofiltration technology employing trickle bed air biofilters (TBABs). Following the completion of this experimental study, additional data analysis was performed to develop a simple lumped-parameter biofilter model, assuming first-order kinetics. This model related the observed biofilter performance to the principle independent physical, thermodynamic, and biochemical parameters. The initial model has subsequently been expanded to incorporate Monod kinetics. In this paper, the development and use of the final explicit lumped-parameter biofilter model and design equation, incorporating Monod kinetics, are presented. To facilitate the application of this model, practical procedures are also presented for the determination of VOC solubility, VOC biokinetic Monod parameters, and the maximum practical biofilter inlet VOC concentration.