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Section Seven INDUSTRIAL WASTES C. METAL PROCESSING WASTES 66 CO-PRECIPITATION OF HEAVY METALS WITH CHROMIUM IN BRASS MILL WASTEWATER Michael J. Pardus, Chief Chemist Cerro Metal Products Bellefonte, Pennsylvania 16823 Raymond W. Regan, Associate Professor Department of Civil Engineering The Pennsylvania State University University Park, Pennsylvania 16802 INTRODUCTION Many industries are being faced with the need to improve their waste management procedures, specifically when hazardous and toxic wastes (HTW) are involved.' The ultimate incentive for an industry is the development and application of a comprehensive management strategy that complies with environmental regulatory requirements, maintains or improves product quality and reduces overall costs. The subject of the presentation concerns the achievement of this ideal at a brass wire operation of an integrated brass and bronze mill (Cerro Metal Products, Bellefonte, Pa.). Indications of the tradeoffs related to operational changes associated with materials substitution are also outlined. The primary source of the information to be presented is after Pardus.2 A paper on related topics was presented by Pardus.3 STATEMENT OF PROBLEM The standard production process for metal forming at the wire mill involved heat treatment, chemical removal of surface oxides, and a drawing step. During the heat treatment step, cuprous oxides formed on the wire surface. Removal of the oxide required oxidation from the cuprous to cupric state. Historically, chromic acid had been used for the oxidation step. The inability to rejuvenate chromic acid pickling solutions and a relatively short working life imposed an economic penalty on manufacturing. Additionally, concern over control of hexavalent chromium during wastewater treatment had resulted in a Cerro policy to substitute its use with a stabilized hydrogen peroxide/ sulfuric acid solution. The impact of the proposed material substitution on the wastewater treatment system was not known. OBJECTIVES This study was initiated to investigate the impact of the proposed materials changes on the removal of heavy metals, primarily copper and zinc, from wire mill wastewaters. Observed trends under a variety of test conditions were used to predict any difficulties in meeting federal discharge requirements. The impact of co-precipitation of these metals with residual chromium and its effect on full scale treatment of process wastewaters were examined. Effects on the volumes of process wastes generated and associated cost factors were also considered. The following were explored in detail: 1) bench scale evaluation of the impact of chromic acid and peroxide pickling on the removal of metals from process wastewaters; 2) comparison of bench scale results to the full scale operation of the pretreatment system during operation with each type of pickling solution; 3) observation of the 43rd Purdue Industrial Waste Conference Proceedings, © 1989 Lewis Publishers, Inc., Chelsea, Michigan 48118. Printed in U.S.A. 579
Object Description
Purdue Identification Number | ETRIWC198866 |
Title | Co-precipitation of heavy metals with chromium in brass mill wastewater |
Author |
Pardus, Michael J. Regan, Raymond W. |
Date of Original | 1988 |
Conference Title | Proceedings of the 43rd Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://e-archives.lib.purdue.edu/u?/engext,39828 |
Extent of Original | p. 579-586 |
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 | 2009-08-14 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page 579 |
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 Seven INDUSTRIAL WASTES C. METAL PROCESSING WASTES 66 CO-PRECIPITATION OF HEAVY METALS WITH CHROMIUM IN BRASS MILL WASTEWATER Michael J. Pardus, Chief Chemist Cerro Metal Products Bellefonte, Pennsylvania 16823 Raymond W. Regan, Associate Professor Department of Civil Engineering The Pennsylvania State University University Park, Pennsylvania 16802 INTRODUCTION Many industries are being faced with the need to improve their waste management procedures, specifically when hazardous and toxic wastes (HTW) are involved.' The ultimate incentive for an industry is the development and application of a comprehensive management strategy that complies with environmental regulatory requirements, maintains or improves product quality and reduces overall costs. The subject of the presentation concerns the achievement of this ideal at a brass wire operation of an integrated brass and bronze mill (Cerro Metal Products, Bellefonte, Pa.). Indications of the tradeoffs related to operational changes associated with materials substitution are also outlined. The primary source of the information to be presented is after Pardus.2 A paper on related topics was presented by Pardus.3 STATEMENT OF PROBLEM The standard production process for metal forming at the wire mill involved heat treatment, chemical removal of surface oxides, and a drawing step. During the heat treatment step, cuprous oxides formed on the wire surface. Removal of the oxide required oxidation from the cuprous to cupric state. Historically, chromic acid had been used for the oxidation step. The inability to rejuvenate chromic acid pickling solutions and a relatively short working life imposed an economic penalty on manufacturing. Additionally, concern over control of hexavalent chromium during wastewater treatment had resulted in a Cerro policy to substitute its use with a stabilized hydrogen peroxide/ sulfuric acid solution. The impact of the proposed material substitution on the wastewater treatment system was not known. OBJECTIVES This study was initiated to investigate the impact of the proposed materials changes on the removal of heavy metals, primarily copper and zinc, from wire mill wastewaters. Observed trends under a variety of test conditions were used to predict any difficulties in meeting federal discharge requirements. The impact of co-precipitation of these metals with residual chromium and its effect on full scale treatment of process wastewaters were examined. Effects on the volumes of process wastes generated and associated cost factors were also considered. The following were explored in detail: 1) bench scale evaluation of the impact of chromic acid and peroxide pickling on the removal of metals from process wastewaters; 2) comparison of bench scale results to the full scale operation of the pretreatment system during operation with each type of pickling solution; 3) observation of the 43rd Purdue Industrial Waste Conference Proceedings, © 1989 Lewis Publishers, Inc., Chelsea, Michigan 48118. Printed in U.S.A. 579 |
Resolution | 300 ppi |
Color Depth | 8 bit |
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