page0673 |
Previous | 1 of 6 | Next |
|
|
Loading content ...
Disposal of Digested Sewage Sludge By Landfill BRIAN W. MAR, Research Professor Civil Engineering Department University of Washington Seattle, Washington CHARLES HENRY Municipality of Metropolitan Seattle Seattle, Washington INTRODUCTION Sludge disposal in an economic and environmentally acceptable fashion is a universal problem in waste water treatment. Solutions have ranged from direct discharge into receiving waters to reclamation and reprocessing for its soil conditioning or energy value. A number of seacoast cities have or are still directly discharging sludge in coastal waters. Both Federal and State agencies have instructed the Municipality of Metropolitan Seattle (METRO) to terminate the discharge of sludge into Puget Sound by 1972. In response to this directive METRO enlisted the resources ofthe University of Washington, Department of Civil Engineering, to participate in a joint sludge disposal demonstration project. The initial concept of the demonstration project was to develop a process that would employ wet digested sewage sludge to reclaim seashore land. This appeared to be attractive since the treatment plant is located on the shores of Puget Sound and the City of Seattle had expressed an interest in developing a parkway along the intertidal zone near the plant. Since there are many coastal cities faced with sludge disposal problems and there was a great interest by public agencies in acquiring and developing lands for parkways, open spaces, and recreational areas, the concept of land reclamation with digested sludge appeared to be a solution to a nationwide problem. The initial construction of the M ETRO West Point treatment facility provided a four- acre diked area in the intertidal zone adjacent to the plant site for future digester construction. Digested sludge was originally discharged after screening with the primary plant effluent to Puget Sound. Although METRO studies have shown that this practice has no observable deleterious effects on the receiving water, this research program was initiated to comply with State and Federal direction to seek an alternative method of disposal. The research goal was to demonstrate the practicality of filling this lagoon with sludge as a means of sludge disposal and land reclamation. Practicality was interpreted as being economically feasible and environmentally acceptable. Offsite disposal was not considered for this study, although some attractive alternatives can be suggested. The West Point plant provides primary treatment of sewage from a combined sewer system. Settled sewage is fed to a three unit high rate digester system. During periods of high rainfall, the design peak wet weather flow of 325 million gallons per day is exceeded. Peak flows up to 400 mgd have been successfully handled by the plant. Operation of the digesters under high flow conditions is challenging and the resulting digested sludge has a one to three percent solid content (weight). The solids will normally contain about 50 percent volatile material, but the non-volatile content will increase during periods of high rainfall when sediment from the combined sewers enters the system. During the demonstration period approximately 25 tons per day of dry digested solids will be produced by processing 250.000 gallons per day of sludge from the digesters. Since the plant is located on the beach, large quantities of beach sand are available for use as cover. 673
Object Description
Purdue Identification Number | ETRIWC197261 |
Title | Disposal of digested sludge by landfill |
Author |
Mar, Brian W. Henry, Charles |
Date of Original | 1972 |
Conference Title | Proceedings of the 27th Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://earchives.lib.purdue.edu/u?/engext,20246 |
Extent of Original | p. 673-678 |
Series | Engineering extension series no. 141 |
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 | 2009-06-08 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page0673 |
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 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Transcript | Disposal of Digested Sewage Sludge By Landfill BRIAN W. MAR, Research Professor Civil Engineering Department University of Washington Seattle, Washington CHARLES HENRY Municipality of Metropolitan Seattle Seattle, Washington INTRODUCTION Sludge disposal in an economic and environmentally acceptable fashion is a universal problem in waste water treatment. Solutions have ranged from direct discharge into receiving waters to reclamation and reprocessing for its soil conditioning or energy value. A number of seacoast cities have or are still directly discharging sludge in coastal waters. Both Federal and State agencies have instructed the Municipality of Metropolitan Seattle (METRO) to terminate the discharge of sludge into Puget Sound by 1972. In response to this directive METRO enlisted the resources ofthe University of Washington, Department of Civil Engineering, to participate in a joint sludge disposal demonstration project. The initial concept of the demonstration project was to develop a process that would employ wet digested sewage sludge to reclaim seashore land. This appeared to be attractive since the treatment plant is located on the shores of Puget Sound and the City of Seattle had expressed an interest in developing a parkway along the intertidal zone near the plant. Since there are many coastal cities faced with sludge disposal problems and there was a great interest by public agencies in acquiring and developing lands for parkways, open spaces, and recreational areas, the concept of land reclamation with digested sludge appeared to be a solution to a nationwide problem. The initial construction of the M ETRO West Point treatment facility provided a four- acre diked area in the intertidal zone adjacent to the plant site for future digester construction. Digested sludge was originally discharged after screening with the primary plant effluent to Puget Sound. Although METRO studies have shown that this practice has no observable deleterious effects on the receiving water, this research program was initiated to comply with State and Federal direction to seek an alternative method of disposal. The research goal was to demonstrate the practicality of filling this lagoon with sludge as a means of sludge disposal and land reclamation. Practicality was interpreted as being economically feasible and environmentally acceptable. Offsite disposal was not considered for this study, although some attractive alternatives can be suggested. The West Point plant provides primary treatment of sewage from a combined sewer system. Settled sewage is fed to a three unit high rate digester system. During periods of high rainfall, the design peak wet weather flow of 325 million gallons per day is exceeded. Peak flows up to 400 mgd have been successfully handled by the plant. Operation of the digesters under high flow conditions is challenging and the resulting digested sludge has a one to three percent solid content (weight). The solids will normally contain about 50 percent volatile material, but the non-volatile content will increase during periods of high rainfall when sediment from the combined sewers enters the system. During the demonstration period approximately 25 tons per day of dry digested solids will be produced by processing 250.000 gallons per day of sludge from the digesters. Since the plant is located on the beach, large quantities of beach sand are available for use as cover. 673 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Tags
Comments
Post a Comment for page0673