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OPTIMIZATION OF HEAVY METALS WASTEWATER TREATMENT EFFLUENT QUALITY VERSUS SLUDGE TREATMENT Jack McVaugh, Industrial Process Engineer William T. Wall, Jr., Industrial Marketing Group Manager Envirex, Inc. Waukesha, Wisconsin 53186 INTRODUCTION In ever-growing numbers industries with wastewater pretreatment facilities are finding that all problems are not immediately solved when their systems "go on-line." There must be a "shakedown" period in which the system operation is optimized and operating personnel become familiar with the flexibility and controllability of their system. During this shakedown, operating variables are changed until effluent requirements are met, sometimes giving little attention to how these variables affect the overall operation and economics of the pretreatment facility. This report concerns an optimization study conducted at the pretreatment facility of a heavy equipment manufacturer. The system normally accomplishes greater than 90% removal of suspended solids, total chrome, iron, lead and zinc. Average influent concentrations of these pollutants are 200, 26, 56, 8.9 and 42 mg/1, respectively. BACKGROUND In March 1975, a wastewater pretreatment facility was installed at a major farm equipment manufacturing plant. The combined wastewater flow of 100-200 gpm originates from paint stripping, prepaint washing, nickel-chrome plating, zinc plating, quenching and dust collecting, as well as compressor and cooling tower blowdown operations. Treatment consists of primary clarification to remove free oil and settleable solids, pH adjustment by lime addition, solids contact and flocculation, sedimentation for heavy metal removal, and sludge treatment by gravity thickening and vacuum filtration. The project was initiated nearly 2 years before, when pollution control studies indicated the magnitude and complexity of the wastewater disposal problem. Compounding the problem was a 20-month deadline to have a system on stream. This deadline dictated an immediate course of action, and inquiries-whose bid scope defined influent conditions, set effluent standards, and included construction specifications-were issued to firms with "total systems" capabilities. By taking this approach, the time requirement was met, and the responsibility for system performance was clearly defined. The owner's internal manpower requirements were minimized as the project coordination, engineering, purchasing and construction functions were performed by the supplier with approval of the owner. The initial task of the supplier was to conduct a plant wastewater survey to verify the work performed earlier. All manufacturing processes contributing wastewater were observed and flow rates monitored. Composite as well as individual grab samples were collected for pollutant evaluation. Composite samples were also used in laboratory treatability studies, conducted to allow the supplier's process engineers to develop a flow scheme and to select and size the individual pieces of equipment. The treatability tests were designed to approximate full-scale operations, with appropriate scale-up factors, whenever possible. The parameters predicted from the results of this testwork are compared to actual operating conditions later in this report. The flow scheme selected is shown in Figure 1. Process design was followed by detailed equipment and tankage design, pump selection, piping design and building layout. All these were continually developed and modified as the unit processes were refined. The final layouts and utility requirements were 17
Object Description
Purdue Identification Number | ETRIWC197602 |
Title | Optimization of heavy metals wastewater treatment effluent quality versus sludge treatment |
Author |
McVaugh, Jack Wall, William T. |
Date of Original | 1976 |
Conference Title | Proceedings of the 31st Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://e-archives.lib.purdue.edu/u?/engext,27048 |
Extent of Original | p. 17-25 |
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 | 2009-07-07 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page 17 |
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 | OPTIMIZATION OF HEAVY METALS WASTEWATER TREATMENT EFFLUENT QUALITY VERSUS SLUDGE TREATMENT Jack McVaugh, Industrial Process Engineer William T. Wall, Jr., Industrial Marketing Group Manager Envirex, Inc. Waukesha, Wisconsin 53186 INTRODUCTION In ever-growing numbers industries with wastewater pretreatment facilities are finding that all problems are not immediately solved when their systems "go on-line." There must be a "shakedown" period in which the system operation is optimized and operating personnel become familiar with the flexibility and controllability of their system. During this shakedown, operating variables are changed until effluent requirements are met, sometimes giving little attention to how these variables affect the overall operation and economics of the pretreatment facility. This report concerns an optimization study conducted at the pretreatment facility of a heavy equipment manufacturer. The system normally accomplishes greater than 90% removal of suspended solids, total chrome, iron, lead and zinc. Average influent concentrations of these pollutants are 200, 26, 56, 8.9 and 42 mg/1, respectively. BACKGROUND In March 1975, a wastewater pretreatment facility was installed at a major farm equipment manufacturing plant. The combined wastewater flow of 100-200 gpm originates from paint stripping, prepaint washing, nickel-chrome plating, zinc plating, quenching and dust collecting, as well as compressor and cooling tower blowdown operations. Treatment consists of primary clarification to remove free oil and settleable solids, pH adjustment by lime addition, solids contact and flocculation, sedimentation for heavy metal removal, and sludge treatment by gravity thickening and vacuum filtration. The project was initiated nearly 2 years before, when pollution control studies indicated the magnitude and complexity of the wastewater disposal problem. Compounding the problem was a 20-month deadline to have a system on stream. This deadline dictated an immediate course of action, and inquiries-whose bid scope defined influent conditions, set effluent standards, and included construction specifications-were issued to firms with "total systems" capabilities. By taking this approach, the time requirement was met, and the responsibility for system performance was clearly defined. The owner's internal manpower requirements were minimized as the project coordination, engineering, purchasing and construction functions were performed by the supplier with approval of the owner. The initial task of the supplier was to conduct a plant wastewater survey to verify the work performed earlier. All manufacturing processes contributing wastewater were observed and flow rates monitored. Composite as well as individual grab samples were collected for pollutant evaluation. Composite samples were also used in laboratory treatability studies, conducted to allow the supplier's process engineers to develop a flow scheme and to select and size the individual pieces of equipment. The treatability tests were designed to approximate full-scale operations, with appropriate scale-up factors, whenever possible. The parameters predicted from the results of this testwork are compared to actual operating conditions later in this report. The flow scheme selected is shown in Figure 1. Process design was followed by detailed equipment and tankage design, pump selection, piping design and building layout. All these were continually developed and modified as the unit processes were refined. The final layouts and utility requirements were 17 |
Resolution | 300 ppi |
Color Depth | 8 bit |
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