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Section Five WASTE MANAGEMENT A. LANDFILLS/LEACHATE 53 DESIGN OF LANDFILL LEACHATE RECIRCULATION SYSTEMS BASED ON FLOW CHARACTERISTICS A. Basel Al-Yousfi, Doctoral Candidate Department of Civil Engineering University of Pittsburgh Pittsburgh, Pennsylvania 15261 Frederick G. Pohland, Professor and Weidlein Chair Department of Civil Engineering, University of Pittsburgh Pittsburgh, Pennsylvania 15261 N. C. Vasuki, Chief Executive Officer Delaware Solid Waste Authority Dover, Delaware 19901 INTRODUCTION Most sanitary landfills are constructed and operated to facilitate single pass leaching of infiltrated rainfall through the refuse mass. Due to this gradual leaching process, stabilization in such landfills may require many years, thereby extending the acid formation and methane fermentation phases of waste stabilization over long periods of time. Under these circumstances, decomposition of biodegradable fractions of solid waste will be impeded and less complete, often disallowing commercial recovery of methane gas, and delaying closure and possible future reuse of the landfill. In contrast, leachate recycle may be used as a management alternative which requires the containment, collection and recirculation of leachate back through the landfill media. Such an option offers more rapid development of active anaerobic microbial populations and increases reaction rates (and predictability) as well as compresses the time required for stabilization of the readily available organic constituents.1-3 This accelerated stabilization is enhanced by the routine and uniform exposure of microorganisms to constituents in the leachate, thereby providing the necessary contact time, nutrients and substrates for efficient conversion and degradation. Hence, leachate recirculation essentially converts the landfill into an anaerobic bioreactor which accelerates the conversion of organic material to end- products. Moreover, such a landfill exhibits higher and more efficient attenuation of toxic substances, and a much lower risk of adverse public health and environmental impacts.4"5 In addition, predictable and economical methane gas recovery can be achieved,6-7 and the landfill space can be reclaimed for further use much sooner than under single pass operation. Although, the operational strategy of leachate recirculation has been proven to be a suitable management option for municipal landfills, design and operational criteria have not been established to implement and control this technology. Accordingly, the principle objective of this study was to develop design configurations and criteria for landfill leachate recirculation systems. This objective was satisfied by examining and utilizing the fundamentals of leachate flow characteristics within the solid waste matrix, taking into account site-specific circumstances, including solid waste loadings, meteorological conditions and associated potential for leachate (and gas) generation. This resulted in a recirculation frequency which was sufficient to encourage leachate contact and distribution throughout the waste mass, yet restricted in quantity in order to avoid leachate accumulation and pooling within the landfill. Therefore, moisture was made available to sustain accelerated degradation of organic materials in accordance with the sequential phases of landfill stabilization, and to minimize shortcircuiting, channeling and ponding within the landfill. 47th Purdue Industrial Waste Conference Proceedings, 1992 Lewis Publishers, Inc., Chelsea, Michigan 48118. Printed in U.S.A. 491
Object Description
Purdue Identification Number | ETRIWC199253 |
Title | Design of landfill leachate recirculation systems based on flow characteristics |
Author |
Al-Yousfi, A. Basel Pohland, Frederick G., 1931- Vasuki, N. C. |
Date of Original | 1992 |
Conference Title | Proceedings of the 47th Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://e-archives.lib.purdue.edu/u?/engext,43678 |
Extent of Original | p. 491-500 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital object copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Date Digitized | 2009-12-10 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page 491 |
Collection Title | Engineering Technical Reports Collection, Purdue University |
Repository | Purdue University Libraries |
Rights Statement | Digital copyright Purdue University. All rights reserved. |
Language | eng |
Type (DCMI) | text |
Format | JP2 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Transcript | Section Five WASTE MANAGEMENT A. LANDFILLS/LEACHATE 53 DESIGN OF LANDFILL LEACHATE RECIRCULATION SYSTEMS BASED ON FLOW CHARACTERISTICS A. Basel Al-Yousfi, Doctoral Candidate Department of Civil Engineering University of Pittsburgh Pittsburgh, Pennsylvania 15261 Frederick G. Pohland, Professor and Weidlein Chair Department of Civil Engineering, University of Pittsburgh Pittsburgh, Pennsylvania 15261 N. C. Vasuki, Chief Executive Officer Delaware Solid Waste Authority Dover, Delaware 19901 INTRODUCTION Most sanitary landfills are constructed and operated to facilitate single pass leaching of infiltrated rainfall through the refuse mass. Due to this gradual leaching process, stabilization in such landfills may require many years, thereby extending the acid formation and methane fermentation phases of waste stabilization over long periods of time. Under these circumstances, decomposition of biodegradable fractions of solid waste will be impeded and less complete, often disallowing commercial recovery of methane gas, and delaying closure and possible future reuse of the landfill. In contrast, leachate recycle may be used as a management alternative which requires the containment, collection and recirculation of leachate back through the landfill media. Such an option offers more rapid development of active anaerobic microbial populations and increases reaction rates (and predictability) as well as compresses the time required for stabilization of the readily available organic constituents.1-3 This accelerated stabilization is enhanced by the routine and uniform exposure of microorganisms to constituents in the leachate, thereby providing the necessary contact time, nutrients and substrates for efficient conversion and degradation. Hence, leachate recirculation essentially converts the landfill into an anaerobic bioreactor which accelerates the conversion of organic material to end- products. Moreover, such a landfill exhibits higher and more efficient attenuation of toxic substances, and a much lower risk of adverse public health and environmental impacts.4"5 In addition, predictable and economical methane gas recovery can be achieved,6-7 and the landfill space can be reclaimed for further use much sooner than under single pass operation. Although, the operational strategy of leachate recirculation has been proven to be a suitable management option for municipal landfills, design and operational criteria have not been established to implement and control this technology. Accordingly, the principle objective of this study was to develop design configurations and criteria for landfill leachate recirculation systems. This objective was satisfied by examining and utilizing the fundamentals of leachate flow characteristics within the solid waste matrix, taking into account site-specific circumstances, including solid waste loadings, meteorological conditions and associated potential for leachate (and gas) generation. This resulted in a recirculation frequency which was sufficient to encourage leachate contact and distribution throughout the waste mass, yet restricted in quantity in order to avoid leachate accumulation and pooling within the landfill. Therefore, moisture was made available to sustain accelerated degradation of organic materials in accordance with the sequential phases of landfill stabilization, and to minimize shortcircuiting, channeling and ponding within the landfill. 47th Purdue Industrial Waste Conference Proceedings, 1992 Lewis Publishers, Inc., Chelsea, Michigan 48118. Printed in U.S.A. 491 |
Resolution | 300 ppi |
Color Depth | 8 bit |
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