State of the Art Report on Mathematical Methods for Groundwater Pollution Source Identification

The reliable assessment of hazards or risks arising from groundwater contamination problems and the design of efficient and effective techniques to mitigate these problems require the capability to predict the behavior of chemical contaminants in flowing water. Most attempts at quantifying contaminant transport have relied on a solution of some form of a well-known governing equation referred to as advection-dispersion-reaction equation. To choose an appropriate remediation strategy, knowledge of the contaminant release source and time release history becomes pertinent. As additional contaminated sites are being detected, it is almost impossible to perform exhaustive drilling, testing, and chemical fingerprint analysis every time. Moreover, chemical fingerprinting and site records are not sufficient to allow a unique solution for the timing of source releases. The purpose of this paper is to present and review mathematical methods that have been developed during the past 15 years to identify the contaminant source location and recover the time release history.     

State of the Art Report on Mathematical Methods for Groundwater Pollution Source Identification

The reliable assessment of hazards or risks arising from groundwater contamination problems and the design of efficient and effective techniques to mitigate these problems require the capability to predict the behavior of chemical contaminants in flowing water. Most attempts at quantifying contaminant transport have relied on a solution of some form of a well-known governing equation referred to as advection-dispersion-reaction equation. To choose an appropriate remediation strategy, knowledge of the contaminant release source and time release history becomes pertinent. As additional contaminated sites are being detected, it is almost impossible to perform exhaustive drilling, testing, and chemical fingerprint analysis every time. Moreover, chemical fingerprinting and site records are not sufficient to allow a unique solution for the timing of source releases. The purpose of this paper is to present and review mathematical methods that have been developed during the past 15 years to identify the contaminant source location and recover the time release history.     

A State of the Art Report on Industrial Precipitator Control Equipment

Informative report No. 3 has been prepared to provide background information on the origin, purpose, and general theory of operation of automatic power controls for industrial electrostatic precipitators. A comprehensive body of literature describing the process and mechanisms of dust collection in precipitators is readily available to those interested, but information on the control equipment used with the process is widely scattered. This report is intended to provide assistance toward the understanding of manufacturers’ literature describing specific control apparatus, and it may be used as a starting point for more intensive investigation of the subject. To the latter end, a history of the development of these controls and a bibliography of pertinent literature and patents has been included. It is expected that this report will be of particular interest to technical and supervisory personnel concerned with the selection, evaluation, and operation of precipitation equipment.     

Remote Sensing Tools Assist in Environmental Forensics. Part I: Traditional Methods

This is part one of a two-part discussion, in which we will provide an overview of the use of aerial photography, topographic mapping and photogrammetry in environmental enforcement actions. The visualization of spatial relationships of natural and man-made features can focus the scope of environmental investigation, and provide a simple, yet quantitative, historical record of changes in conditions on a site. Aerial photography has been used in environmental remote sensing since the early part of the 20th century. Aerial photos are valuable tools for environmental assessment because they provide objective, detailed documentation of surface conditions at a specific time. Furthermore, they can generally be obtained even in cases where access on the ground is denied to investigators. From aerial photos, precise quantitative information can be collected using photogrammetry. Such measurement and positional data can be produced in digital format for input into a Geographic Information System (GIS) for computerized analysis and display. Other information derived from aerial photographs requires specialized photointerpretive skills and experience. These include the recognition of vegetation mortality, oil-spill damage, and the ecological quality of water bodies. The location, extent and historical change of hazardous waste sites can be documented on topographic maps. These maps are often created from aerial photographs, and display the extent and location of real-world features by symbolizing them. The major advantage of maps over aerial photos is that maps can show things that are not visible from the air, while omitting unnecessary and distracting information. Because maps are derived products, they may contain bias in content and presentation, and they must be backed up by careful documentation and quality assurance protocols.     

Remote Sensing Tools Assist in Environmental Forensics. Part I: Traditional Methods

This is part one of a two-part discussion, in which we will provide an overview of the use of aerial photography, topographic mapping and photogrammetry in environmental enforcement actions. The visualization of spatial relationships of natural and man-made features can focus the scope of environmental investigation, and provide a simple, yet quantitative, historical record of changes in conditions on a site. Aerial photography has been used in environmental remote sensing since the early part of the 20th century. Aerial photos are valuable tools for environmental assessment because they provide objective, detailed documentation of surface conditions at a specific time. Furthermore, they can generally be obtained even in cases where access on the ground is denied to investigators. From aerial photos, precise quantitative information can be collected using photogrammetry. Such measurement and positional data can be produced in digital format for input into a Geographic Information System (GIS) for computerized analysis and display. Other information derived from aerial photographs requires specialized photointerpretive skills and experience. These include the recognition of vegetation mortality, oil-spill damage, and the ecological quality of water bodies. The location, extent and historical change of hazardous waste sites can be documented on topographic maps. These maps are often created from aerial photographs, and display the extent and location of real-world features by symbolizing them. The major advantage of maps over aerial photos is that maps can show things that are not visible from the air, while omitting unnecessary and distracting information. Because maps are derived products, they may contain bias in content and presentation, and they must be backed up by careful documentation and quality assurance protocols.     

Linking Chemistry to Law in Environmental Forensics

The right to a healthy environment is of capital importance, which is why this matter calls for a detailed study, taking into account implications of both chemistry and law. The present study describes the current level of environmental protection, significant pieces of legislation, and five case studies regarding human rights violations. It reveals reports concerning air quality in Romania and in Europe. A large body of evidence emphasizes that permanent legislation revisions and new legal implementations place Europe on the right track, but plenty of issues remain to be solved until main pollutant emissions drop and the environmental situation becomes at least satisfactory.     

Flue Gas Desulfurization: The State of the Art

ABSTRACT

Coal-fired electricity-generating plants may use SO₂ scrubbers to meet the requirements of Phase II of the Acid Rain SO₂ Reduction Program. Additionally, the use of scrubbers can result in reduction of Hg and other emissions from combustion sources. It is timely, therefore, to examine the current status of SO₂ scrubbing technologies. This paper presents a comprehensive review of the state of the art in flue gas desulfurization (FGD) technologies for coal-fired boilers.

Data on worldwide FGD applications reveal that wet FGD technologies, and specifically wet limestone FGD, have been predominantly selected over other FGD technologies. However, lime spray drying (LSD) is being used at the majority of the plants employing dry FGD technologies. Additional review of the U.S. FGD technology applications that began operation in 1991 through 1995 reveals that FGD processes of choice recently in the United States have been wet limestone FGD, magnesium-enhanced lime (MEL), and LSD. Further, of the wet limestone processes, limestone forced oxidation (LSFO) has been used most often in recent applications.

The SO₂ removal performance of scrubbers has been reviewed. Data reflect that most wet limestone and LSD installations appear to be capable of ~90% SO₂ removal. Advanced, state-of-the-art wet scrubbers can provide SO₂ removal in excess of 95%.

Costs associated with state-of-the-art applications of LSFO, MEL, and LSD technologies have been analyzed with appropriate cost models. Analyses indicate that the capital cost of an LSD system is lower than those of same capacity LSFO and MEL systems, reflective of the relatively less complex hardware used in LSD. Analyses also reflect that, based on total annualized cost and SO₂ removal requirements: (1) plants up to ~250 MW_e in size and firing low- to medium-sulfur coals (i.e., coals with a sulfur content of 2% or lower) may use LSD; and (2) plants larger than 250 MW_e and firing medium- to high-sulfur coals (i.e., coals with a sulfur content of 2% or higher) may use either LSFO or MEL.     

试论环境监测报告的审核

环境监测报告的审核是环境监测质最保证工作的最后环节。作者从审核程序、审核人员资质、审核脚容等方面对报告的审核进行了阐述。     

规划环境影响评价指标体系及评价方法浅析

对规划环境影响评价的内容作出了概述性的介绍，并根据规划环境影响评价的特点，得出规划环境影响评价的指标体系应包括自然环境指标、生态环境指标、资源利用指标、能源利用指标和社会经济指标5大体系。列举了当前适用于规划环境影响评价的技术方法，并对其进行简单的对比分析。     

Statistical Methods and Pitfalls in Environmental Data Analysis

This paper reviews four commonly used statistical methods for environmental data analysis and discusses potential pitfalls associated with application of these methods through real case study data. The four statistical methods are percentile and confidence interval, correlation coefficient, regression analysis, and analysis of variance (ANOVA). The potential pitfall for estimation of percentile and confidence interval includes the automatic assumption of a normal distribution to environmental data, which so often show a log-normal distribution. The potential pitfall for correlation coefficient includes the use of a wide range of data points in which the maximum in value may trivialize other smaller data points and consequently skew the correlation coefficient. The potential pitfall for regression analysis includes the propagation of uncertainties of input variables to the regression model prediction, which may be even more uncertain. The potential pitfall for ANOVA includes the acceptance of a hypothesis as a weak argument to imply a strong conclusion. As demonstrated in this paper, we may draw very different conclusions based on statistical analysis if the pitfalls are not identified. Reminder and enlightenment obtained from the pitfalls are given at the end of this article.     

Statistical Methods and Pitfalls in Environmental Data Analysis

This paper reviews four commonly used statistical methods for environmental data analysis and discusses potential pitfalls associated with application of these methods through real case study data. The four statistical methods are percentile and confidence interval, correlation coefficient, regression analysis, and analysis of variance (ANOVA). The potential pitfall for estimation of percentile and confidence interval includes the automatic assumption of a normal distribution to environmental data, which so often show a log-normal distribution. The potential pitfall for correlation coefficient includes the use of a wide range of data points in which the maximum in value may trivialize other smaller data points and consequently skew the correlation coefficient. The potential pitfall for regression analysis includes the propagation of uncertainties of input variables to the regression model prediction, which may be even more uncertain. The potential pitfall for ANOVA includes the acceptance of a hypothesis as a weak argument to imply a strong conclusion. As demonstrated in this paper, we may draw very different conclusions based on statistical analysis if the pitfalls are not identified. Reminder and enlightenment obtained from the pitfalls are given at the end of this article.     

Evolution of Organic Analytical Methods in Environmental Forensic Chemistry

Over the past few decades the development of environmental regulations, advances in analytical chemistry and other scientific disciplines, and increased rigor in quality control procedures have created a new discipline, environmental forensics. The need for analytical methods that determine qualitatively and quantitatively organic compounds in the environment, especially in drinking waters, was recognized in the early 1950s. These methods were developed gradually by the early 1960s. The important tools of gas chromatography and mass spectroscopy that evolved in the 1970s provided the early environmental forensic chemist for the first time with the ability to produce scientifically sound data that was admissible in court. By the 1990s, multivariate statistical techniques became available and accepted, including principal component analysis (PCA) and polytopic vector analysis (PVA). These techniques, coupled with the advancing analytical methods, have enabled forensic investigator tools to evaluate and demonstrate unique attributes of a set of data. Analyses of marker compounds, PCBs, PCDD/Fs and petroleum hydrocarbons are all shown to be potentially valuable in deciphering the source and fate of contamination. This paper shows how advancements in environmental analytical chemistry provide the forensic chemist with tools to assess the source(s) of site contamination.     

Evolution of Organic Analytical Methods in Environmental Forensic Chemistry

Over the past few decades the development of environmental regulations, advances in analytical chemistry and other scientific disciplines, and increased rigor in quality control procedures have created a new discipline, environmental forensics. The need for analytical methods that determine qualitatively and quantitatively organic compounds in the environment, especially in drinking waters, was recognized in the early 1950s. These methods were developed gradually by the early 1960s. The important tools of gas chromatography and mass spectroscopy that evolved in the 1970s provided the early environmental forensic chemist for the first time with the ability to produce scientifically sound data that was admissible in court. By the 1990s, multivariate statistical techniques became available and accepted, including principal component analysis (PCA) and polytopic vector analysis (PVA). These techniques, coupled with the advancing analytical methods, have enabled forensic investigator tools to evaluate and demonstrate unique attributes of a set of data. Analyses of marker compounds, PCBs, PCDD/Fs and petroleum hydrocarbons are all shown to be potentially valuable in deciphering the source and fate of contamination. This paper shows how advancements in environmental analytical chemistry provide the forensic chemist with tools to assess the source(s) of site contamination.