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FATE OF BASIC POLLUTANTS IN TREATMENT OF COKE-PLANT EFFLUENTS J.J. Ganczarczyk, Professor Department of Civil Engineering University of Toronto Toronto, Canada M5S 1A4 INTRODUCTION Treatment effects of coke-plant effluents are usually evaluated in terms of removal of only some characteristic pollutants like mono-hydric phenols, cyanide and ammonia. Determination of other important components of this wastewater like thiocyanate and some derivatives of polynuclear aromatic hydrocarbons is often neglected. Determinations of wastewater composed characteristics like biochemical oxygen demand (BOD) chemical oxygen demand (COD), dissolved solids, extractables, color, etc. are made only occasionally. A justification for such an approach may be found in some respective analytical difficulties and uncertainties, but the growing requirements for receiving water bodies demand much broader control of the wastewater treatment. In the scope of this work some new analytical information is presented on coke-plant effluents treatment in laboratory, pUot-scale and full-scale, to support other avadable data on the subject. On this basis, fate of specific wastewater chemical components and composed characteristics is established for particular stages of the wastewater pre-treatment and treatment [ 1 ]. Special attention is directed to formulate the characteristics effectiveness limits for particular treatment methods. This approach is considered to facUitate the selection of treatment methods and treatment strategy for the specific treatment requirements. Table I presents a range of component concentrations characterizing typical coke-plant effluents. This information is basically relevant for coke-plants generating more than 40 U.S. gallons of effluents per ton of coke (150 L/t). The majority of the studied coke plants generate a wastewater flow of 50-100 U.S. gal/t of coke (190-380 L/t). Usually, this flow is a function of the coal moisture contents and depends also on various additional wastewater streams being connected to the excess of flushing liquor which constitutes the major component of the wastewater. Coal sulfur and nitrogen contents as well as the cokeing temperature affect the concentrations of majority of the chemical compounds constituting these effluents. Figure 1 shows a conventional flow-sheet of coke-plant effluents treatment. The indicated treatment sequence is followed later in discussing fates of the particular pollutants. TRANSFORMATIONS OF BASIC POLLUTANTS Fate of Phenols and Phenolics To simplify analytical procedures, phenols in this wastewater are often determined as phenoUcs, the latter showing quite often misleadingly high concentrations. Usual first step of phenol and phenolics removal is solvent extraction. Its results are shown in Table II. This operation is preferential for cresols versus phenol (Table HI) and also removes from wastewater piridine bases and neutral ods. The relatively smaU popularity of solvent extraction for treatment of coke-plant effluents in North America is justified by a low market value of the recovered material. However, an application of such treatment can make the subsequent biological treatment less expensive and more efficient. 325
Object Description
Purdue Identification Number | ETRIWC198031 |
Title | Fate of basic pollutants in treatment of coke-plant effluents |
Author | Ganczarczyk, Jerzy J., 1928- |
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. 325-331 |
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 325 |
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 | FATE OF BASIC POLLUTANTS IN TREATMENT OF COKE-PLANT EFFLUENTS J.J. Ganczarczyk, Professor Department of Civil Engineering University of Toronto Toronto, Canada M5S 1A4 INTRODUCTION Treatment effects of coke-plant effluents are usually evaluated in terms of removal of only some characteristic pollutants like mono-hydric phenols, cyanide and ammonia. Determination of other important components of this wastewater like thiocyanate and some derivatives of polynuclear aromatic hydrocarbons is often neglected. Determinations of wastewater composed characteristics like biochemical oxygen demand (BOD) chemical oxygen demand (COD), dissolved solids, extractables, color, etc. are made only occasionally. A justification for such an approach may be found in some respective analytical difficulties and uncertainties, but the growing requirements for receiving water bodies demand much broader control of the wastewater treatment. In the scope of this work some new analytical information is presented on coke-plant effluents treatment in laboratory, pUot-scale and full-scale, to support other avadable data on the subject. On this basis, fate of specific wastewater chemical components and composed characteristics is established for particular stages of the wastewater pre-treatment and treatment [ 1 ]. Special attention is directed to formulate the characteristics effectiveness limits for particular treatment methods. This approach is considered to facUitate the selection of treatment methods and treatment strategy for the specific treatment requirements. Table I presents a range of component concentrations characterizing typical coke-plant effluents. This information is basically relevant for coke-plants generating more than 40 U.S. gallons of effluents per ton of coke (150 L/t). The majority of the studied coke plants generate a wastewater flow of 50-100 U.S. gal/t of coke (190-380 L/t). Usually, this flow is a function of the coal moisture contents and depends also on various additional wastewater streams being connected to the excess of flushing liquor which constitutes the major component of the wastewater. Coal sulfur and nitrogen contents as well as the cokeing temperature affect the concentrations of majority of the chemical compounds constituting these effluents. Figure 1 shows a conventional flow-sheet of coke-plant effluents treatment. The indicated treatment sequence is followed later in discussing fates of the particular pollutants. TRANSFORMATIONS OF BASIC POLLUTANTS Fate of Phenols and Phenolics To simplify analytical procedures, phenols in this wastewater are often determined as phenoUcs, the latter showing quite often misleadingly high concentrations. Usual first step of phenol and phenolics removal is solvent extraction. Its results are shown in Table II. This operation is preferential for cresols versus phenol (Table HI) and also removes from wastewater piridine bases and neutral ods. The relatively smaU popularity of solvent extraction for treatment of coke-plant effluents in North America is justified by a low market value of the recovered material. However, an application of such treatment can make the subsequent biological treatment less expensive and more efficient. 325 |
Resolution | 300 ppi |
Color Depth | 8 bit |
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