bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trend detection in the presence of covariates: Stagewise versus multiple regression
Authors: Smith Eric P. , Rose Kenneth A. 
Published: February 2007

AbstractThe assessment of trend in environmental quality is an important task for environmental managers and scientists. Much recent research has focused on the proper methodology for the assessment of trend, for example, when the data are correlated or censored. An equally important problem is discussed in this paper, that of the specifying underlying models that relate the environmental quality time series to other time dependent covariates and how to adjust for these covariates. Two basic approaches for the adjustment for covariates are stagewise regression and multiple regression. We use simulation, analysis and a data set from the Chesapeake Bay, U.S.A., to show that the approach based on stagewise regression can yield misleading results. We show that the multiple regression approach is generally more powerful than the stagewise method.
Use of robust methods in the analysis of suspended particulate air pollution: A case study in Malaysia
Authors: Abdullah Mokhtar , Sani Sham 
Published: February 2007

AbstractThis paper describes several analyses in which a robust method, namely the least median of squares (LMS) has been used in the development of a mathematical model to relate suspended particulate air pollution concentration to meteorological factors. The robust procedure provides a formal method that not only pays due attention to anomalies or outliers in the data but also reduces the influence of the outliers. The study showed that the robust procedure yielded more reliable results than did the classical least squares (LS) approach.
Non‐parametric trend test of baltic sea data
Authors: Sandén P. , Rahm L. , Wulff F. 
Published: February 2007

AbstractThe recently reported tendencies toward decreasing total amounts of silicate in the Baltic Sea are investigated by use of non‐parametric trend analysis. The period 1968‐1986 showed significant falling trends in surface waters from the whole system. The deepest parts of the Baltic proper did in contrast reveal strong increasing trends. These trends are more pronounced during the latter part of the analysis period which is characterized by stagnant conditions in the Baltic proper. These conditions have been prevailing since the major inflow in 1976. The causes of the observed changes are unclear. The increased load of nutrients and accompanying increase in primary production is, however, one factor. Another is coupled to the stagnation conditions of the Baltic Proper.
Inverse sampling in case control studies
Authors: Singh Padam , Aggarwal Abha Rani 
Published: February 2007

AbstractIn case control studies when the relative risk is very high the expected frequencies of diseased but not exposed and non‐diseased but exposed are generally very low. In such situations inverse sampling can be used. This paper presents the relevant theory of inverse sampling in case control studies. The expressions for bias and Mean Square Error (MSE) have been derived. It has been observed that the estimator under inverse sampling is unbiased and more efficient as compared to the estimator under usual case control studies.
A search for the source of the nile's change‐points
Authors: Macneill I. B. , Tang S. M. , Jandhyala V. K. 
Published: February 2007

AbstractThe annual discharges of the Nile River at Aswan are examined for change‐points in both mean level and in serial correlation structure. The methodology used identifies 1899 as a change‐point for the mean level; this has been observed by others. Second and third change‐points for the mean level are identified at 1954 and 1965. In addition, a change is observed in the serial correlation structure of the detrended series. For the segment prior to 1907 this structure is compatible with white noise; after 1907 it is characterized by strong serial correlation and is closely modelled by an ARMA(2,2) model. This serial correlation is taken into account when identifying the 1954 and 1965 changes in mean level.The history of the Nile basin is examined for significant hydrological and political events that might be connected with these change‐points. It is speculated that the changes in mean level at 1899 and 1954 and in serial correlation structure are changes in the data due to measurement and hydropolitical issues. A competing hypothesis for the cause of changes in mean level involves long‐term climatic shifts that could be modelled by long‐memory or doubly stochastic models.
Encountered data, statistical ecology, environmental statistics, and weighted distribution methods
Authors: Patil Ganapati P. 
Published: February 2007

AbstractWe have begun to experience in data gathering and analysis in modern ecological and environmental work a space age/stone age syndrome. Also we are challenged to break into the cycle of no information, new information, and non‐information while dealing with soft data, hard looks, and prudent decision‐making involving errors of the third and the fourth kind in addition to those of the first and the second type.Weighted distribution methods arise in the context of data gathering, modeling, inference, and computing, and help provide a unified approach in dealing with encountered data.
In‐situ biodenitrification of the S‐3 ponds
Authors: Napier J. M. , Bustamante R. B. 
Published: February 2007

AbstractA process has been developed for removing nitrates and heavy metals from open ponds. Four ponds were treated using the developed process. The process steps involved neutralization of the ponds, followed by biological denitrification. The nitrate ions were reduced from 40,000 mg/L to <50 mg/L at an average denitrification decrease rate of 300 mg/L per day. The denitrified water was then flocculated and filtered to remove solids. The water quality met discharge water chemical limits as well as biological test requirements.
Control of emissions from an air stripper treating contaminated groundwater
Authors: Byers W. D. 
Published: February 2007

AbstractThe performance and costs of two well water treatment systems are compared: an aqueous‐phase granular‐activated‐carbon (GAC) system, and an air stripping system with emission control. Both systems were installed to remove volatile organic compounds (VOC's) from the Verona Well Field, which supplies potable water to Battle Creek, Michigan.
Recovery of volatile organics from small industrial sources
Authors: Spivey James J. 
Published: February 2007

AbstractThe recovery of volatile organic compounds (VOCs) from contaminated air generated by small industrial operations such as coating operations and spray painting is an important alternative to other air cleaning techniques such as thermal or catalytic incineration. Three technologies—adsorption, absorption, and condensation—are discussed herein. The focus of this article, and by far the most widely applied technique, is activated carbon adsorption. Commercial systems are generally designed for gas streams containing roughly 300 to 5,000 ppm VOC at flow rates from 200 to 100,000 ft3 (STP)/min (5.7 to 2,830 m3 (STP)/min).General design parameters and costs, along with their application to example cases, are given for VOC recovery by activated carbon adsorption and condensation. No commercial systems specifically for VOC recovery by absorption have yet been reported, though this technology is extremely important for other air pollution control needs.
Heterogeneous ozonation kinetics of pollutants in wastewater
Authors: Whitlow J. E. , Roth J. A. 
Published: February 2007

AbstractOzonation is a technically viable wastewater treatment alternative for achieving stringent effluent limitations. Limited feasibility data have been reported in the literature on a wide range of pollutants. These data are primarily time concentration profiles for semi‐batch air‐ozone or oxygen ozone gas phase contacting with pollutant‐water systems. These data have been evaluated and correlated where possible in correlations of a form suitable for scaleup to continuous systems. Pollutants include ammonia, phenol, styrene and cyanides.
Evaluating potential impacts from accidental gaseous releases of toxic chemicals
Authors: Heinold David , Smith Douglas , Schwab Bradley 
Published: February 2007

AbstractMany companies involved with toxic gases are seeking an independent evaluation of liability in the event of an accidental release. A detailed methodology is presented with a hypothetical example based on case studies from several recent risk assessments. These demonstrate such typical components of an analysis as site reconnaissance, accident scenario development, air quality assessment, health impacts potential and remedial action review.
Development of options for minimizing hazardous waste generation
Authors: Drabkin Marvin , Fromm Carl , Freeman Harry M. 
Published: February 2007

AbstractThe U.S. EPA is encouraging hazardous waste generators to develop programs to reduce the generation of hazardous waste. To encourage such programs the Agency's Hazardous Waste Engineering Research Laboratory is supporting the development and evaluation of a model hazardous waste minimization audit procedure. The procedure was tested in several facilities during the summer of 1986.
Alternatives for reducing the risks of hazardous material storage facilities
Authors: Hendershot Dennis C. 
Published: February 2007

AbstractBecause they contain relatively large inventories, hazardous material storage facilities often represent a major contribution to the overall risk from a chemical manufacturing facility. Application of basic chemical engineering principles to the problem of reducing or eliminating the consequences of a release can identify means to substantially reduce the intrinsic hazards of such facilities. Also discussed are examples of possible approaches, including material substitution, inventory reduction, dilution, and refrigeration.
Hydrogenation and recycle of organic waste streams
Authors: Kalnes T. N. , James R. B. 
Published: February 2007

AbstractEach year, billions of gallons of organic waste liquids are generated. Recently implemented EPA regulations now provide an economic driving force to minimize the net production of these waste materials. A hydrocarbon refining process employing catalytic hydrogenation has been expanded from current petroleum and petrochemical applications to the treatment and recycle of hazardous organic waste streams. In this paper, three classes of hazardous organic wastes are studied: PCB insulating liquids, halogenated petrochemical by‐products, and residue from distillate oil sulfuric acid treatment. Pilot plant data are presented as the basis for evaluating the environmental and economic advantages of hydrogenation and reuse.
Economic evaluation of waste minimization options
Authors: Karam Joseph G. , Cin Carl S. T. , Tilly Jean 
Published: February 2007

AbstractThree analytical tools developed to assist hazardous waste generators in identifying and evaluating the economic feasibility of waste minimization options are presented. Ranging in scope and sophistication from comprehensive financial analysis models to simple data management systems, these analytical tools are: a financial analysis model; a multi‐option model (MOM); and a future liability assessment model.
Absorption, electrodialysis, and additional regeneration in two flue gas SO2/NOx cleanup processes
Authors: Walker Richard J. , Pennline Henry W. 
Published: February 2007

AbstractTwo new processes that can each simultaneously remove sulfur dioxide (SO2) and nitrogen oxides (NOx) from flue gas by wet scrubbing with a liquor that contains an SO2‐removal agent and a metal chelate for NOx removal are described. They are similar, except for different by‐products. In both, the spent scrubbing liquor is regenerated with respect to sulfur by an electrodialysis stack employing cation‐ and anion‐selective membranes. Sulfate salts are produced as by‐products. Experimentally, the liquor has been regenerated with respect to NOx removal ability by holding it at elevated temperature, but the mechanism is not well understood.
Evaluation of control strategies for volatile organic compounds in indoor air
Authors: Ramanathan Kumar , Debler Vickie L. , Kosusko Michael , Sparks Leslie E. 
Published: February 2007

AbstractThe Air and Energy Engineering Research Laboratory of the U.S. Environmental Protection Agency (U.S. EPA) conducts and sponsors research on technology to reduce or eliminate emissions of potentially toxic volatile organic compounds (VOCs) from industrial/commercial sources.The realization that indoor air environments, where humans spend the majority of their time, also contain significant levels of VOCs has led to a number of EPA‐sponsored studies on monitoring, modeling, and controlling these compounds. The purpose of this paper is twofold: to present an overview of the problem of indoor air pollution by VOCs and approaches to solving it, and to report the results of a study to determine the feasibility of carbon adsorption for control of VOCs in indoor air.
Indoor radon: Source characterization
Authors: Kunz Charles O. 
Published: February 2007

AbstractSources for indoor radon including radon from soils and rock infiltrating the substructure of a home and radon from water usage, building materials, outside air, and burning natural gas are reviewed. It is generally accepted that radon from soils and rock is the principal source for indoor radon. Correlations between indoor radon levels and soil characteristics are discussed for six areas in New York State. These results indicate that soils can be characterized for radon availability and transport into homes by a combination of soil parameters including the source strength (soil radium concentration or soil‐gas radon concentration), soil permeability for gas flow and, depth of soils to bedrock or water table.
Electrophysical sorption of single carbon halogenated solvents onto soil
Authors: Mokrauer J. E. , Kosson D. S. 
Published: February 2007

AbstractSorption of halogenated single carbon organic contaminants onto a sandy loam has been found to be controlled by the electrostatic attraction between a slightly negatively (δ−) charged clay particle and a positively (δ+) charged carbon atom within the solvent molecule. Adsorption isotherms for chloroform, bromodichloromethane and methylene chloride indicate that the extent of sorption appears to have a direct functional relationship to the molecular charge distribution within the solvent molecule, and to the atomic radii of the molecular substituents of the contaminant. When a carbon atom is saturated with highly electronegative substituents (e.g. carbon tetrachloride), an electron cloud surrounds the molecule and shields the slightly positive (δ+) carbon nuclei. This shielding effect limits the sorption that occurs. A study on carbon tetrachloride sorption resulted in no detectable sorption onto the sandy loam soil. This theory of adsorption is defined as Electrophysical Sorption (EPS) because it reflects the combination of electrostatic and physical contributions to sorption.
Destruction of aromatic pollutants by UV light catalyzed oxidation with hydrogen peroxide
Authors: Sundstrom D. W. , Weir B. A. , Klei H. E. 
Published: February 2007

AbstractToxic and hazardous compounds are often present in water at low concentrations, which can make their removal difficult and costly by conventional treatment processes. A promising method for destroying pollutants in water is ultraviolet (UV) catalyzed oxidation by hydrogen peroxide. The effectiveness of this process was determined for typical aromatic compounds including benzene, toluene, chlorobenzene, phenol, 2‐chlorophenol, 2,4‐dichlorophenol, 2,4,6‐trichlorophenol, dimethyl phthalate, and diethyl phthalate. The reactions were conducted in a quartz annular reactor equipped with a low‐pressure mercury lamp. Of the aromatics studied, reaction rates were fastest with 2,4,6‐trichlorophenol and slowest with the phthalates. Analyses of reacted samples by HPLC and GC/MS indicated that the aromatics formed many intermediates that could be destroyed by extending the treatment time. An empirical rate expression was developed to correlate the results.
Two strategies for PCB soil remediation: Biodegradation and surfactant extraction
Authors: McDermott John B. , Unterman Ronald , Brennan Michael J. , Brooks Ronald E. , Mobley David P. , Schwartz Charles C. , Dietrich David K. 
Published: February 2007

AbstractTwo strategies for the cleanup of PCB‐contaminated soils are being developed: biodegradation by selected bacteria and extraction with aqueous surfactant solutions. Extensive biodegradation has been demonstrated by Pseudomonas putida strain LB400 in studies with Aroclor‐spiked laboratory soil and soil from a New York State site containing 525 ppm of transformed Aroclor 1242 (depleted of di‐ and trichlorobiphenyls). Solutions of sodium dodecylbenzenesulfonate can extract PCB from soils. A bench‐scale process with four countercurrent stages effected the cleanup of a heavy clayey soil. The PCB was recovered from the surfactant solution by precipitation with calcium chloride, reducing the mass of contaminated material to 3% of the original soil mass.
Fundamental experiments on thermal desorption of contaminants from soils
Authors: Lighty Joann S. , Silcox Geoff D. , Pershing David W. , Cundy Vic A. , Linz David G. 
Published: February 2007

AbstractThe goals of this research are to develop an understanding of the transport phenomena that occur during the desorption of contaminants from soil and to obtain rate information. This information can then be used to develop a model to predict the performance of full‐scale thermal treatment systems for optimization and cost reduction.
Waste treatability tests of spent solvent and other organic wastewaters
Authors: Turner Ronald J. 
Published: February 2007

AbstractSome commercial and industrial facilities treat RCRA spent solvent wastewaters by steam stripping, carbon adsorption, and/or biological processes. Thirteen facilities were visited by EPA's Office of Research and Development (ORD) from June 1985 to September 1986, to conduct sampling and analysis episodes and to determine the levels of performance achievable by these and other treatment processes. This paper summarizes the results of five of the tests: two steam strippers, two carbon adsorption systems, and one activated sludge biological system.
Improved clarifier performance and capacity through the use of a flow contraction baffle
Authors: Silveston Peter L. , Hudgins Robert R. 
Published: February 2007

AbstractPilot‐scale tests were conducted over several years on the effectiveness of a flow contraction baffle installed in a pilot‐scale clarifier to separate solids from both primary sewage and activated sludge mixed liquor. Tests used two matched, 1.2‐m diameter clarifiers, one of which was fitted with the baffle, in the form of a truncated cone descending from the effluent weir. Effectiveness of the flow contraction baffle results from the suppression of additive interference of density waves always present in clarifiers as well as provision for the uniform withdrawal of the clarified liquor.
Low temperature thermal treatment (LT3) of volatile organic compounds from soil: A technology demonstrated
Authors: Nielson Roger K. , Cosmos Michael G. 
Published: February 2007

AbstractWeston has developed, tested, demonstrated, and operated a transportable system to remove, through evaporation, and subsequently destroy volatile organic contaminants in soil and sludges. The process is called Low Temperature Thermal Treatment (LT3). The purpose of this patented process is to restore the soil to its original condition, making it suitable for on‐site backfill and to eliminate the long term liability and potential costs associated with off‐site transportation and disposal.
Incineration of solid waste
Authors: Lee C. C. , Huffman George L. 
Published: February 2007

AbstractThe concern over solid waste disposal and dump‐site clean‐up resulted in the passage of three major U.S. environmental laws. They are the Resource Conservation and Recovery Act (RCRA) of 1976, Public Law 94–580, the Toxic Substances Control Act (TSCA) of 1976, Public Law 94–469, and the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) of 1980, Public Law 96–510. The implementation of these three laws has intensified incineration research, because incineration represents the highest degree of destruction and environmental control possible for various waste types. This paper reviews the fundamentals of incineration and provides an incinerator design example to show how combustion fundamentals are applied to an incineration system.
Relationships between laboratory and pilot‐scale combustion of some chlorinated hydrocarbons
Authors: Chang Daniel P. Y. , Sorbo Nelson W. , Law Chung King , Steeper Richard R. , Richards Marta K. , Huffman George L. 
Published: February 2007

AbstractFactors governing the occurrence of trace amounts of residual organic substance emissions (ROSEs) in full‐scale incinerators are not fully understood. Pilot‐scale spray combustion experiments involving some liquid chlorinated hydrocarbons (CHCs) and their dilute mixtures with hydrocarbons (HC) were undertaken at the USEPA's Center Hill Laboratory. Individual droplet‐burning characteristics of CHCs and HCs were also studied at the University of California, Davis on a more fundamental level to isolate and identify potentially important phenomena. The practical implications of the experimental observations on incinerability ranking, formation of ROSEs, and strategies for reducing ROSEs are discussed.
Physical properties and chemical species distributions within municipal waste combuster ashes
Authors: Ontiveros J. L. , Clapp T. L. , Kosson D. S. 
Published: February 2007

AbstractIncineration of municipal solid waste has been viewed as a preferred alternative to landfilling in recent years. Fly ash and bottom ash are of particular concern because of the high concentration of heavy metals on and within the ash matrix. This paper presents chemical, physical, and structural properties of the ashes from several municipal waste combustors. Properties of both the bulk ash and ash fractions separated by particle size are included. Results have shown significant variability based upon both ash type and particle fraction.
Exposure and risk assessment for a proposed hazardous waste incinerator
Authors: Tilly Jean , Dietrich Gary , Pyne Dan 
Published: February 2007

AbstractIn supporting a firm's application for a Part B permit to operate a hazardous waste incinerator in Rhode Island, an exposure/risk assessment was conducted estimating: the maximum concentrations associated with the emissions of hazardous constituents from the incinerator; and the risks due to the exposure to these concentrations. This included determining the probability of the Most Exposed Individual (MEI) developing a cancer case and the number of cancer cases that may develop within a 50‐km radius of the proposed incinerator.
Continuous recovery of heavy metals from MSW incinerator ashes
Authors: Legiec I. A. , Hayes C. A. , Kosson D. S. 
Published: February 2007

AbstractThe leachable concentrations of heavy metals from ash residues from the incineration of municipal solid waste (MSW) often exceeds the Extraction Procedure Toxicity Test (EP Tox) limits, requiring these materials to be considered as a potential hazardous waste. The kinetics of Pb, Cd, and Cr extraction were determined through a series of batch extraction studies. The specific incinerator design and the equilibrium conditions strongly influenced the ash matrix and subsequently the extraction kinetics. Recovery of the metals from the extractant solution was accomplished utilizing electrochemical plating techniques.