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The Biotreatability of Industrial Dye Wastes Before and After Ozonation and Hypochlorination-Dechlorination DR. A. NETZER, Head MR. H.K. MIYAMOTO, Research Engineer Water and Wastewater Treatment Research Canada Centre for Inland Waters Burlington, Ontario L7R 4A6, Canada INTRODUCTION Effluents from the dyehouses of textile mills can create serious environmental problems. Not only are these wastewaters characterized by obnoxious colours and turbidity, but they are also inevitably high in COD, BOD, and TOC. Due to the liberal use of Glauber's salt (sodium sulfate), excessive sodium and chloride levels are also typical. A variety of heavy metals, most notably chromium, copper and zinc, are also frequently present in these effluents. These heavy metal pollutants can originate from several sources. Some heavy metals, such as chromium, copper and cobalt, may form an intrinsic part of the dye molecule in the so-called "premetallized" dyes. Certain types of dyes are marketed in the form of zinc chloride salts. "Tramp" metals may also be retained in the dyes as impurities from the synthesis process of the dyes. Process and auxiliary chemicals may also contain heavy metal pollutants (1). Some dyes are suspected carcinogens (2, 3) and several other chemicals constituents of the dyebath formulation (e.g. surfactants, dispersing agents, levelling compounds, etc.) are known to possess toxic properties (4, 5). At present, most dyehouses discharge their effluents into the municipal sewer system with or without some form of prior treatment. However, most dyes are very resistant to biological degradation and hence colour will very often persist in the treated discharges. Some dyehouses practice chlorination to reduce the colour of their wastes. Although chlorination can often provide a very high degree of decolorization, chlorine itself is toxic to aquatic flora and fauna and the chlorination of such wastes may produce carcinogenic compounds (6, 7, 8). A variety of physical-chemical techniques have been studied in recent years for their applicability in the treatment of textile mill effluents. Among these methods may be included coagulation-flocculation, activated carbon adsorption, photochemical degradation, ultrafiltration, synthetic polymeric resin adsorption and ion-exchange (9, 10). Conventional biological processes are seldom capable of attaining a high degree of purification for dyehouse effluents. This may be due to the presence of toxic, inhibitory or biorefractory compounds. 804
Object Description
Purdue Identification Number | ETRIWC1975070 |
Title | Biotreatability of industrial dye wastes before and after ozonation and hypochlorination-dechlorination |
Author |
Netzer, A. Miyamoto, H. K. |
Date of Original | 1975 |
Conference Title | Proceedings of the 30th Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://earchives.lib.purdue.edu/u?/engext,25691 |
Extent of Original | p. 804-815 |
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 | 2009-06-30 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page804 |
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 | The Biotreatability of Industrial Dye Wastes Before and After Ozonation and Hypochlorination-Dechlorination DR. A. NETZER, Head MR. H.K. MIYAMOTO, Research Engineer Water and Wastewater Treatment Research Canada Centre for Inland Waters Burlington, Ontario L7R 4A6, Canada INTRODUCTION Effluents from the dyehouses of textile mills can create serious environmental problems. Not only are these wastewaters characterized by obnoxious colours and turbidity, but they are also inevitably high in COD, BOD, and TOC. Due to the liberal use of Glauber's salt (sodium sulfate), excessive sodium and chloride levels are also typical. A variety of heavy metals, most notably chromium, copper and zinc, are also frequently present in these effluents. These heavy metal pollutants can originate from several sources. Some heavy metals, such as chromium, copper and cobalt, may form an intrinsic part of the dye molecule in the so-called "premetallized" dyes. Certain types of dyes are marketed in the form of zinc chloride salts. "Tramp" metals may also be retained in the dyes as impurities from the synthesis process of the dyes. Process and auxiliary chemicals may also contain heavy metal pollutants (1). Some dyes are suspected carcinogens (2, 3) and several other chemicals constituents of the dyebath formulation (e.g. surfactants, dispersing agents, levelling compounds, etc.) are known to possess toxic properties (4, 5). At present, most dyehouses discharge their effluents into the municipal sewer system with or without some form of prior treatment. However, most dyes are very resistant to biological degradation and hence colour will very often persist in the treated discharges. Some dyehouses practice chlorination to reduce the colour of their wastes. Although chlorination can often provide a very high degree of decolorization, chlorine itself is toxic to aquatic flora and fauna and the chlorination of such wastes may produce carcinogenic compounds (6, 7, 8). A variety of physical-chemical techniques have been studied in recent years for their applicability in the treatment of textile mill effluents. Among these methods may be included coagulation-flocculation, activated carbon adsorption, photochemical degradation, ultrafiltration, synthetic polymeric resin adsorption and ion-exchange (9, 10). Conventional biological processes are seldom capable of attaining a high degree of purification for dyehouse effluents. This may be due to the presence of toxic, inhibitory or biorefractory compounds. 804 |
Resolution | 300 ppi |
Color Depth | 8 bit |
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