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Section Eleven OIL AND PETROCHEMICAL WASTES 41 CHARACTERIZATION OF HYDROCARBONS REMOVALS IN WASTEWATER FROM AN INTEGRATED OIL REFINERY Noah Galil, Dafna Zeira-Blum and Menahem Rebhun Technion - Israel Institute of Technology Faculty of Civil Engineering Haifa 32000, Israel ABSTRACT The wastewater from an integrated oil refinery is characterized by a diversity of pollutants including hydrocarbons, in free and emulsified form, phenols, including cresols and xylenols. mer- captans, sulfides, ammonia, and cyanides. The wastewater treatment of the reported oil refinery is based on several treatment stages, consisting of gravity separation, chemical coagulation-floc- culation followed by dissolved air flotation, and a combined biological treatment based on two aerated ponds in series and lime flocculation-sedimentation. The effluent is recycled and reused as makeup to the recirculated cooling water system of the refinery. The aim of this study was to identify and quantify the main hydrocarbons groups after the different treatment stages. API separators provided substantial removal of hydrocarbons from about 1,000 mg/L to less than 100 mg/L. Chemical flocculation and dissolved air flotation (DAF) enabled further removal of about 70 mg/L of the hydrocarbons, to 20 mg/L, based on average values. This removal included aliphatics, phenols, naphtalens, and benzenes. This process involved mechanisms of coagulation- flocculation accomplished by physical separation, as well as binding of hydrophobic compounds to nonpolar fractions and stripping of volatile compounds. The combined biological-chemical treatment (BCT) provided removal of hydrocarbons to average values of less than 4 mg/L, and efficient removals of over 90% of the phenols, naphtalens, and benzens. INTRODUCTION An integrated oil refinery is characterized by a diversity of production processes including distillation, catalytic cracking, platforming. ethylene production, sulfur recovery, and others. The results of these various processes is the diversity of pollutants found in wastewater, which contains hydrocarbons, phenol, methyl and di-methyl phenols (cresols and xylenols) mercaptans. sulfides, and ammonia. Spent caustic streams from washeries. especially from gasoline wash- eries, are characterized by very high concentrations of phenols. Acid water at the bottom of stripping towers contains high concentrations of organic matter, sulfides, and cyanides. The wastewater is usually treated in order to achieve the appropriate effluent quality for either discharge to natural recipients or to be reused by the industry. While a substantial part of the hydrocarbons can be removed from the aqueous phase by gravity separation and by dissolved air flotation, all the other organic materials, including residual hydrocarbons, phenols, and other dissolved organics, can be removed only by biological treatment processes. The adopted solutions in order to achieve reliable cost-effective wastewater treatment and reclamation1-2 was based on several treatment stages which include the following elements: 52nd Purdue Industrial Waste Conference Proceedings. 1997. Ann Arbor Pre*,s. C'heKca. Michigan 48118. Printed in U.S.A. 411
Object Description
Purdue Identification Number | ETRIWC199741 |
Title | Characterization of hydrocarbons removals in wastewater from an integrated oil refinery |
Author |
Galil, Noah I. Zeira-Blum, Dafna Rebhun, M. |
Date of Original | 1997 |
Conference Title | Proceedings of the 52nd Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://earchives.lib.purdue.edu/u?/engext,20307 |
Extent of Original | p. 411-418 |
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 | 2009-11-03 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page 411 |
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 | Section Eleven OIL AND PETROCHEMICAL WASTES 41 CHARACTERIZATION OF HYDROCARBONS REMOVALS IN WASTEWATER FROM AN INTEGRATED OIL REFINERY Noah Galil, Dafna Zeira-Blum and Menahem Rebhun Technion - Israel Institute of Technology Faculty of Civil Engineering Haifa 32000, Israel ABSTRACT The wastewater from an integrated oil refinery is characterized by a diversity of pollutants including hydrocarbons, in free and emulsified form, phenols, including cresols and xylenols. mer- captans, sulfides, ammonia, and cyanides. The wastewater treatment of the reported oil refinery is based on several treatment stages, consisting of gravity separation, chemical coagulation-floc- culation followed by dissolved air flotation, and a combined biological treatment based on two aerated ponds in series and lime flocculation-sedimentation. The effluent is recycled and reused as makeup to the recirculated cooling water system of the refinery. The aim of this study was to identify and quantify the main hydrocarbons groups after the different treatment stages. API separators provided substantial removal of hydrocarbons from about 1,000 mg/L to less than 100 mg/L. Chemical flocculation and dissolved air flotation (DAF) enabled further removal of about 70 mg/L of the hydrocarbons, to 20 mg/L, based on average values. This removal included aliphatics, phenols, naphtalens, and benzenes. This process involved mechanisms of coagulation- flocculation accomplished by physical separation, as well as binding of hydrophobic compounds to nonpolar fractions and stripping of volatile compounds. The combined biological-chemical treatment (BCT) provided removal of hydrocarbons to average values of less than 4 mg/L, and efficient removals of over 90% of the phenols, naphtalens, and benzens. INTRODUCTION An integrated oil refinery is characterized by a diversity of production processes including distillation, catalytic cracking, platforming. ethylene production, sulfur recovery, and others. The results of these various processes is the diversity of pollutants found in wastewater, which contains hydrocarbons, phenol, methyl and di-methyl phenols (cresols and xylenols) mercaptans. sulfides, and ammonia. Spent caustic streams from washeries. especially from gasoline wash- eries, are characterized by very high concentrations of phenols. Acid water at the bottom of stripping towers contains high concentrations of organic matter, sulfides, and cyanides. The wastewater is usually treated in order to achieve the appropriate effluent quality for either discharge to natural recipients or to be reused by the industry. While a substantial part of the hydrocarbons can be removed from the aqueous phase by gravity separation and by dissolved air flotation, all the other organic materials, including residual hydrocarbons, phenols, and other dissolved organics, can be removed only by biological treatment processes. The adopted solutions in order to achieve reliable cost-effective wastewater treatment and reclamation1-2 was based on several treatment stages which include the following elements: 52nd Purdue Industrial Waste Conference Proceedings. 1997. Ann Arbor Pre*,s. C'heKca. Michigan 48118. Printed in U.S.A. 411 |
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