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Decontamination of Cyanide Wastes by Methods of Catalytic Oxidation and Adsorption WILHELM BUCKSTEEG, Director Ruhr River Association Essen, Germany INTRODUCTION Wastes of galvanic industries are of particular danger for the receiving waters due to the content of highly toxic cyanides and metal-salts. However, the recent technical development has made it possible to eliminate the toxic substances by chemical treatment or by other methods. The highly toxic cyanides can be oxidized by oxidizing agents, i.e. chlorine; the metal-salts can be neutralized, and the hydroxides which form floes may be removed by sedimentation. A good removal of the toxic substances can be obtained in plants which are operated by skilled operators. The plants are run more or less automatically. Practical experience has shown that a high percentage of removal of cyanides and toxic metal-salts (corresponding nearly to the value that is theoretically attainable) is actually possible in such treatment plants. Hence it is not an unrealistic demand when nowadays the institutions for water pollution control require that the wastes of galvanic industries discharged into a public sewage treatment plant or into the receiving water directly, may not contain more than the allowable limits of contaminants as shown in Table I. TABLE I LIMITING VALUES FOR WASTES OF GALVANIC INDUSTRIES FOR DISCHARGE INTO RECEIVING WATERS (ACCORDING TO GERMAN STANDARDS) Settleable matter 0.3 ml/1 pH 6.5 - 9.0 Metals, dissolved and undissolved Chromium (Cr) 2 mg/l Copper (Cu) 1 mg/l Zinc (Zn) 3 mg/l Cadmium (Cd) 3 mg/l Iron (Fe) 2 mg/l Cyanide (oxidizable by chlorine) 0.1 mg/l Free chlorine 0.5 mg/l Substances which can be extracted by petroleum ether 5 mg/l Nevertheless death of fishes occurs again and again, particularly in areas where a high density of galvanic factories are discharging their wastes into the natural waters. On the other hand some losses of oxygen may take place which - 688 -
Object Description
Purdue Identification Number | ETRIWC196657 |
Title | Decontamination of cyanide wastes by methods of catalytic oxidation and adsorption |
Author | Bucksteeg, Wilhelm |
Date of Original | 1966 |
Conference Title | Proceedings of the 21st Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://earchives.lib.purdue.edu/u?/engext,12965 |
Extent of Original | p. 688-695 |
Series |
Engineering extension series no. 121 Engineering bulletin v. 50, no. 2 |
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 | 2009-05-20 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page 688 |
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 | Decontamination of Cyanide Wastes by Methods of Catalytic Oxidation and Adsorption WILHELM BUCKSTEEG, Director Ruhr River Association Essen, Germany INTRODUCTION Wastes of galvanic industries are of particular danger for the receiving waters due to the content of highly toxic cyanides and metal-salts. However, the recent technical development has made it possible to eliminate the toxic substances by chemical treatment or by other methods. The highly toxic cyanides can be oxidized by oxidizing agents, i.e. chlorine; the metal-salts can be neutralized, and the hydroxides which form floes may be removed by sedimentation. A good removal of the toxic substances can be obtained in plants which are operated by skilled operators. The plants are run more or less automatically. Practical experience has shown that a high percentage of removal of cyanides and toxic metal-salts (corresponding nearly to the value that is theoretically attainable) is actually possible in such treatment plants. Hence it is not an unrealistic demand when nowadays the institutions for water pollution control require that the wastes of galvanic industries discharged into a public sewage treatment plant or into the receiving water directly, may not contain more than the allowable limits of contaminants as shown in Table I. TABLE I LIMITING VALUES FOR WASTES OF GALVANIC INDUSTRIES FOR DISCHARGE INTO RECEIVING WATERS (ACCORDING TO GERMAN STANDARDS) Settleable matter 0.3 ml/1 pH 6.5 - 9.0 Metals, dissolved and undissolved Chromium (Cr) 2 mg/l Copper (Cu) 1 mg/l Zinc (Zn) 3 mg/l Cadmium (Cd) 3 mg/l Iron (Fe) 2 mg/l Cyanide (oxidizable by chlorine) 0.1 mg/l Free chlorine 0.5 mg/l Substances which can be extracted by petroleum ether 5 mg/l Nevertheless death of fishes occurs again and again, particularly in areas where a high density of galvanic factories are discharging their wastes into the natural waters. On the other hand some losses of oxygen may take place which - 688 - |
Resolution | 300 ppi |
Color Depth | 8 bit |
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