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85 EVALUATING TOXICITY OF SPECIATED METALS FROM METAL DISCHARGING INDUSTRIES Mujde Erten, Project Engineer Malcolm Pirnie Inc., Newport News, Virginia 23606 Jerome L. Pitt, Environmental Engineer U.S. EPA Region VII Kansas City, Kansas 66101 Nord L. Gale, Chairman Life Sciences Department University of Missouri-Rolla Rolla, Missouri 65401 Bobby G. Wixson, Dean College of Sciences Clemson University Clemson, South Carolina 29634 Resit Unal, Assistant Professor Old Dominion University Norfolk, Virginia 23529-0456 INTRODUCTION The aquatic toxicity of metals is a complicated phenomena involving interactions between the environment and the metal pollutants of concern. Predicting the toxic effect that metals have in natural waters requires evaluating the bioavailability of the metal pollutants. The term "bioavailability" reflects the premise that for some heavy metals organisms may be exposed to less than the total amount present in their habitat.1 Earlier studies to determine the toxicity of lead,2,3 cadmium,4"8 and zinc9"'2 to fish indicated that water quality characteristics such as pH and hardness affect bioavailability and toxicity. Further investigations13"15 showed that evaluation of the toxic bioavailability of metals is dependent on the chemical complexation and speciation. The toxicity of heavy metals to aquatic biota is immensely influenced by the physicochemical factors of the specific environment. Many chemical characteristics of the water are important in defining both the chemical species of the metal present and physiological status of the organism being tested.14 The fractionation of metal species has been recognized as an essential step in the assessment of the potential biological uptake, and predicting the toxicity is dependent on understanding the limitations of laboratory toxicity tests and the effects of physicochemical variables at the field site. In recent years, increasing effort has been made to identify the ligands which dominate heavy metal speciation in natural waters, and to develop a speciation scheme for measuring the fraction of the trace metal concentration which is toxic to aquatic biota.16 For a speciation scheme to be useful, however, it must reliably detect all the important toxic forms of the metals present. Also, information must be available about the relative toxicity of the various forms measured by the scheme. The lack of precise and definitive information about the various chemical species of lead, cadmium and zinc which might be present or the relative toxicity of various compounds of these metals have frustrated the development of appropriate and adequate water quality standards. Because of the different species of metals occurring in the environment and the lack of definitive information about their relative toxicities, there is no ideal analytical measurement available for expressing aquatic life criteria for metals of lead, cadmium and zinc. A criterion or a standard for a metal that is based on only one set of environmental variables will be unnecessarily stringent for one type of environment 45th Purdue Industrial Waste Conference Proceedings, © 1991 Lewis Publishers, Inc., Chelsea, Michigan 48118. Printed in U.S.A. 739
Object Description
Purdue Identification Number | ETRIWC199085 |
Title | Evaluating toxicity of speciated metals from metal discharging industries |
Author |
Erten, Mujde U. Pitt, Jerome L. Gale, Nord L. Wixson, Bobby G. Unal, Resit |
Date of Original | 1990 |
Conference Title | Proceedings of the 45th Industrial Waste Conference |
Conference Front Matter (copy and paste) | http://e-archives.lib.purdue.edu/u?/engext,41605 |
Extent of Original | p. 739-750 |
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 | 2009-08-20 |
Capture Device | Fujitsu fi-5650C |
Capture Details | ScandAll 21 |
Resolution | 300 ppi |
Color Depth | 8 bit |
Description
Title | page 739 |
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 | 85 EVALUATING TOXICITY OF SPECIATED METALS FROM METAL DISCHARGING INDUSTRIES Mujde Erten, Project Engineer Malcolm Pirnie Inc., Newport News, Virginia 23606 Jerome L. Pitt, Environmental Engineer U.S. EPA Region VII Kansas City, Kansas 66101 Nord L. Gale, Chairman Life Sciences Department University of Missouri-Rolla Rolla, Missouri 65401 Bobby G. Wixson, Dean College of Sciences Clemson University Clemson, South Carolina 29634 Resit Unal, Assistant Professor Old Dominion University Norfolk, Virginia 23529-0456 INTRODUCTION The aquatic toxicity of metals is a complicated phenomena involving interactions between the environment and the metal pollutants of concern. Predicting the toxic effect that metals have in natural waters requires evaluating the bioavailability of the metal pollutants. The term "bioavailability" reflects the premise that for some heavy metals organisms may be exposed to less than the total amount present in their habitat.1 Earlier studies to determine the toxicity of lead,2,3 cadmium,4"8 and zinc9"'2 to fish indicated that water quality characteristics such as pH and hardness affect bioavailability and toxicity. Further investigations13"15 showed that evaluation of the toxic bioavailability of metals is dependent on the chemical complexation and speciation. The toxicity of heavy metals to aquatic biota is immensely influenced by the physicochemical factors of the specific environment. Many chemical characteristics of the water are important in defining both the chemical species of the metal present and physiological status of the organism being tested.14 The fractionation of metal species has been recognized as an essential step in the assessment of the potential biological uptake, and predicting the toxicity is dependent on understanding the limitations of laboratory toxicity tests and the effects of physicochemical variables at the field site. In recent years, increasing effort has been made to identify the ligands which dominate heavy metal speciation in natural waters, and to develop a speciation scheme for measuring the fraction of the trace metal concentration which is toxic to aquatic biota.16 For a speciation scheme to be useful, however, it must reliably detect all the important toxic forms of the metals present. Also, information must be available about the relative toxicity of the various forms measured by the scheme. The lack of precise and definitive information about the various chemical species of lead, cadmium and zinc which might be present or the relative toxicity of various compounds of these metals have frustrated the development of appropriate and adequate water quality standards. Because of the different species of metals occurring in the environment and the lack of definitive information about their relative toxicities, there is no ideal analytical measurement available for expressing aquatic life criteria for metals of lead, cadmium and zinc. A criterion or a standard for a metal that is based on only one set of environmental variables will be unnecessarily stringent for one type of environment 45th Purdue Industrial Waste Conference Proceedings, © 1991 Lewis Publishers, Inc., Chelsea, Michigan 48118. Printed in U.S.A. 739 |
Resolution | 300 ppi |
Color Depth | 8 bit |
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