page 95 |
Previous | 1 of 10 | Next |
|
|
Loading content ...
A CASE STUDY-TANNERY MEETS EPA PRETREATMENT STANDARDS Carl V. Huber, Vice President Thomas A. Doane, Project Manager Fishbeck, Thompson, Carr, & Huber, Inc. Grand Rapids, Michigan 49506 INTRODUCTION Wolverine World Wide, Inc. is a leading pigskin tanner in the United States. Although it owns and operates many facilities within the nation, the tanning is performed entirely at its Rockford, Michigan, facdity, located immediately north of Grand Rapids. The tannery tans approximately 36,288 kg of green salted hides per day with an additional 18,144- 22,680 kg per week of "croupons." The processes performed at the Rockford tannery include the beam house (hair burn), chrome tan, and color and paste. The industrial category as defined by the Industrial Classification System is 3111. The tannery practices all beam house operations in one mill rather than separating the lime-sulfide and chrome tan processes. For this reason, all wastes are generally mixed in the process sewer and are not conveyed separately. Table I indicates raw wastewater characteristics. These are general averages for the years 1974 and 1975. Since that date and since the project conception, Wolverine World Wide has made a successful attempt to conserve water, thereby reducing the flow to the wastewater treatment plant. This, as well as elevated concentrations, wdl appear in later data. Prior to any expansion, wastewater was rough screened and treated with lime in an area adjacent to the beam house and then transported by gravity sewer to the waste treatment plant. Waste traveled through an open grit chamber which was primarily used for removing large quantities of grease before the wastewater was pumped to the primary clarifier. Prior to primary clarification, the waste was treated with a coagulant and polymer. This coagulant was usually ferrous sulfate fed in concentrations of 1000-1500 mg/1. The waste was then settled in a second clarifier where additional coagulants were added if necessary. Prior to discharge to the public sewer system in the City of Rockford, caustic was added for pH control to prevent the formation of hydrogen sulfide (H2S) in the long sewer system to the City of Grand Rapids. Sludge was pumped from the underflow of the two clarifiers and conditioned before being de watered by vacuum filtration. Under normal circumstances, the sludge was conditioned with ferric chloride and lime, de watered to approximately 75% moisture and disposed of in a nearby landfill. The grease was skimmed not only from the grit chamber but also from both clarifiers; it was also disposed of in a landfdl (Figure 1). Table I. Raw Wastewater Characteristics Average Minimum Maximum Hide Production (kg) 33,566 5,443 48,082 Flow (m3) 1,662 761 2,677 BOD (mg/1) 3,734 2,700 4,600 Suspended Solids (mg/1) 4,806 2,539 8,287 Sulfide (mg/1) 300 100 700 Chrome (mg/1) 82 20 183 Grease (mg/1) 1,000 95
Object Description
Purdue Identification Number | ETRIWC198011 |
Title | Case study-tannery meets EPA pretreatment standards |
Author |
Huber, Carl V. Doane, Thomas A. |
Date of Original | 1980 |
Conference Title | Proceedings of the 35th Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://e-archives.lib.purdue.edu/u?/engext,31542 |
Extent of Original | p. 95-104 |
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 | 2009-10-22 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page 95 |
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 | A CASE STUDY-TANNERY MEETS EPA PRETREATMENT STANDARDS Carl V. Huber, Vice President Thomas A. Doane, Project Manager Fishbeck, Thompson, Carr, & Huber, Inc. Grand Rapids, Michigan 49506 INTRODUCTION Wolverine World Wide, Inc. is a leading pigskin tanner in the United States. Although it owns and operates many facilities within the nation, the tanning is performed entirely at its Rockford, Michigan, facdity, located immediately north of Grand Rapids. The tannery tans approximately 36,288 kg of green salted hides per day with an additional 18,144- 22,680 kg per week of "croupons." The processes performed at the Rockford tannery include the beam house (hair burn), chrome tan, and color and paste. The industrial category as defined by the Industrial Classification System is 3111. The tannery practices all beam house operations in one mill rather than separating the lime-sulfide and chrome tan processes. For this reason, all wastes are generally mixed in the process sewer and are not conveyed separately. Table I indicates raw wastewater characteristics. These are general averages for the years 1974 and 1975. Since that date and since the project conception, Wolverine World Wide has made a successful attempt to conserve water, thereby reducing the flow to the wastewater treatment plant. This, as well as elevated concentrations, wdl appear in later data. Prior to any expansion, wastewater was rough screened and treated with lime in an area adjacent to the beam house and then transported by gravity sewer to the waste treatment plant. Waste traveled through an open grit chamber which was primarily used for removing large quantities of grease before the wastewater was pumped to the primary clarifier. Prior to primary clarification, the waste was treated with a coagulant and polymer. This coagulant was usually ferrous sulfate fed in concentrations of 1000-1500 mg/1. The waste was then settled in a second clarifier where additional coagulants were added if necessary. Prior to discharge to the public sewer system in the City of Rockford, caustic was added for pH control to prevent the formation of hydrogen sulfide (H2S) in the long sewer system to the City of Grand Rapids. Sludge was pumped from the underflow of the two clarifiers and conditioned before being de watered by vacuum filtration. Under normal circumstances, the sludge was conditioned with ferric chloride and lime, de watered to approximately 75% moisture and disposed of in a nearby landfill. The grease was skimmed not only from the grit chamber but also from both clarifiers; it was also disposed of in a landfdl (Figure 1). Table I. Raw Wastewater Characteristics Average Minimum Maximum Hide Production (kg) 33,566 5,443 48,082 Flow (m3) 1,662 761 2,677 BOD (mg/1) 3,734 2,700 4,600 Suspended Solids (mg/1) 4,806 2,539 8,287 Sulfide (mg/1) 300 100 700 Chrome (mg/1) 82 20 183 Grease (mg/1) 1,000 95 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Tags
Comments
Post a Comment for page 95