Abstracts from Recent Issues: Vol. 23, No.3, August 1996

BIOCHEMICAL AND PHYSICAL PROCESSES IN LANDFILLS

POTENTIAL USE OF FLY ASH IN COLOMBIAN BLENDED CEMENTS

ENVIRONMENTAL IMPACT ASSESSMENT STUDY FOR THE SELECTION OF SITES FOR DEVELOPING A HAZARDOUS WASTE DISPOSAL FACILITY--A CASE STUDY

AN INTEGRATED, MULTISTAGE, MULTICRITERIA METHODOLOGY FOR SITING HAZARDOUS WASTE MANAGEMENT FACILITIES: THEORETICAL FRAMEWORK AND ILLUSTRATIVE APPLICATION

HOUSEHOLD ADOPTION OF A NEW TECHNOLOGY: THE CASE OF WOOD PELLET STOVES

BIOCHEMICAL AND PHYSICAL PROCESSES IN LANDFILLS
 
 

Mutasem El-Fadel*

American University of Beirut
Faculty of Engineering and Architecture
850 Third Avenue
New York, NY 10022
 
 

Angelos N. Findikakis and James O. Leckie

Department of Civil Engineering,
Stanford University
Stanford, CA 94305
USA
 
 

ABSTRACT

This paper presents a mathematical model describing biochemical and physical processes in landfills. The model incorporates biokinetic equations describing the dynamics of the microbial landfill ecosystem into multi-component (methane, carbon dioxide, and nitrogen) time dependent gas and heat generation and transport models. The model accounts for effects of temperature variations with time on transport properties and biochemical processes in a landfill environment. The resulting integrated biokinetic, gas, and heat generation and transport model was used to simulate field data from the Mountain View Controlled Landfill Project, California. Model simulation results were in good agreement with data from the landfill field test. The model can be used to simulate the gas production, migration, and emission at a landfill site, and assess the parameters that control biological, physical, and chemical processes in a landfill ecosystem.

Key words: Solid waste, landfill, biodegradation, numerical modeling

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POTENTIAL USE OF FLY ASH IN COLOMBIAN BLENDED CEMENTS
 
 

Ruby MejÌa de GutiÈrrez
and
Silvio Delvasto A.

Engineering Materials Department
Universidad del Valle
Cali, Colombia
 
 

ABSTRACT

The current yearly Colombian production of coal combustion residues is approximately 800.000 tonnes and the size of the disposal problem of these wastes is quite large. The electric utilities alone burn over 1.5 millions tons of coal annually; as a result 270.000 tons of fly ash are produced. In this research four different fly ashes have been compared. Measurements include their chemical composition, pozzolanic activity, effect of the amount of material added on the compressive strength, heat of hydration and durability properties. It is shown that the partial replacement of cement with fly ash reduces the Coefficient of Chloride Diffusion. It is suggested that this is because the pore structures of the blended cement mortars are discontinuous and tortuous.

It is demonstrated that a fly ash of good quality, incorporated in an optimun proportion, is an excellent cement replacement material.

Key words: Coal; Coal wastes; fly ash; Pozzolans; Blended Portland Cements; Mortars; Durability Properties; Chloride Difussion

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ENVIRONMENTAL IMPACT ASSESSMENT STUDY FOR THE SELECTION OF SITES FOR DEVELOPING A HAZARDOUS WASTE DISPOSAL FACILITY -- A CASE STUDY
 
 

Dr. A. K. Saxena
Yogesh Gupta
Bhatti Priyesh D.

Environment Division
National Productivity Council
5-6, Institutional Area, Lodi Road,
New Delhi - 110 003
INDIA
 
 

ABSTRACT

The improper disposal of hazardous wastes has led to the contamination of soil, groundwater and surface water throughout the world. In India, in order to manage such wastes in an environmentally sound manner, the Government in 1989 notified the "Hazardous Waste (Management & Handling) Rules." As part of these regulations, sites for the disposal of hazardous waste have to be determined based on Environmental Impact Assessment (EIA) studies. In this regard, an EIA study for developing an hazardous waste disposal facility was carried out by National Productivity Council of India in Gujarat State, located in the western part of India. The study was sponsored by the Gujarat State Pollution Control Board. This paper deals with (a) the Site Assessment and Selection Criteria evolved for selecting a suitable site under Indian environmental conditions and (b) an EIA study conducted for the development of hazardous waste disposal facility in Ahmedabad District of Gujarat, India.

Key words: Industrial Estates, Inventorying, Secured Landfill, Site Selection Criteria, Hydraulic Conductivity, Environmental Impact Assessment

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AN INTEGRATED, MULTISTAGE, MULTICRITERIA METHODOLOGY FOR SITING HAZARDOUS WASTE MANAGEMENT FACILITIES: THEORETICAL FRAMEWORK AND ILLUSTRATIVE APPLICATION
 
 

Prof. Helen Briassoulis

Department of Human Geography
University of the Aegean
Mytilene, Lesvos
Greece

and

Prof. Michel Installe

Center for Systems Engineering and Applied Mechanics
Catholic University of Louvain
Louvain-la-Neuve
Belgium
 
 

ABSTRACT

The siting of hazardous waste management facilities is an important consideration in the context of hazardous waste management as it touches upon issues of economic efficiency, environmental soundness, and social fairness. The paper presents a theoretical analytical framework to guide the site selection process for this kind of facility and provides an illustrative case study application. A brief review of the literature on hazardous facilities siting methodologies is offered in the first section which are synthesized into a multistage, multicriteria methodological framework which is presented and detailed in the second section of the paper. The third section provides an illustrative case study application of the proposed methodology which refers to the siting problem of a hazardous wastes incinerator in Greece. The paper ends with a summary of the main features of the methodology and suggests future research directions. The proposed methodology: (1) allows for the consideration of more than one criteria in siting hazardous waste management facilities which belong to different hierarchical levels (stages) of the siting decision process; (2) places special emphasis on the environmental criteria both as regards the provision of specific environmental functions and attributes as well as regards the environmental impacts of these facilities; (3) offers a framework to deal with multiactor decision settings and conflict resolution; (4) provides for computer support of certain phasesóthe site evaluation and the group decision-making phasesóof the siting process; (5) it is simple and understandable, a feature especially important for its implementability.

Key words: Siting of hazardous facilities; Multicriteria decision

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HOUSEHOLD ADOPTION OF A NEW TECHNOLOGY: THE CASE OF WOOD PELLET STOVES
 
 

R.K. Skaggs

F.K. Owensby

R.R. Lansford

Department of Agricultural Economics and Agricultural Business
New Mexico State University
Las Cruces, New Mexico
 
 

ABSTRACT

Household wood pellet stove (WPS) awareness, ownership, and potential acquisition in Albuquerque, New Mexico is analyzed using a multiple-choice model. Using data obtained from a telephone survey, households were divided into four groups: current WPS owners, non-owners considering ownership, non-owners not considering ownership, and those unaware of WPS technology. The research found few current WPS owners. WPS considerers are likely to live in larger than average homes, already use a conventional woodstove and/or be frequent fireplace users, or heat their homes with propane or butane. However, across all variations in socio-economic and woodburning or home-heating characteristics, households are most likely to either have no knowledge of WPS technology or to know about the stoves but not be considering the purchase of one. Improved winter air quality through changes in residential woodburning practices in Albuquerque will require increases in public awareness of WPS technology and its benefits, and target marketing by the WPS industry.

Key words: Technology adoption, woodburning, air quality, home heating, econometric analysis

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