Toxicity of Chloride, Sulfate and Carbonate Mixtures and Their Influence on the Toxicity of Other Chemicals Common to Textile Effluents
Project Title: Toxicity of Chloride, Sulfate and Carbonate Mixtures and Their Influence on the Toxicity of Other Chemicals Common to Textile Effluents
Continuation Project? Yes No
Research Team Leader Professor Warren Perkins Phone 706-542-4885
Team Leader's e-mail wperkins@fcs.uga.edu
Team Leader's institution University of Georgia
Industry Partner Contact Dr. Jeff Silliman Phone 864-503-1844
Industry Partner's Organization Milliken and Company
Proposed Research Team:
Researcher Name and Institution Phone
George L. Baughman TMI - UGA 706-542-4883
Peter J. Lasier USGS/WSFR - UGA 706-546-2186
Warren S. Perkins TMI - UGA 706-542-4885
Parley V. Winger USGS/WSFR - UGA 706-546-2146
Requested Funds:
College or University $$ Requested
University of Georgia $75,000
Total TIP-PFFP Funds Requested for FY2003 $75,000
Executive Summary
The overall objective of this study is to provide information that can be used to lower the incidence of failures in chronic toxicity tests (reproduction inhibition) of textile wastewaters. Specifically, the goal is to understand the effect of salinity (inorganic salts) and common organic chemicals in eliciting chronic toxicity in textile wastewater. Salinity, or total dissolved solids (TDS), is often cited as the most probable source of toxicity in textile wastewater. Yet, the published literature contains very little information on chronic toxicity of ions such as chloride, sulfate and bicarbonate. Furthermore, virtually nothing has been published concerning their influence on chronic toxicity of organic substances commonly encountered in textile effluents.
Effluents produced from textile dyeing and finishing processes often contain substantial concentrations of chloride, sulfate and carbonate due to dyeing processes that utilize sodium and/or alkali solutions. In addition to elevated salinity, textile effluents frequently contain commonly used organic chemicals such as naphthalene sulfonates, lignin sulfonates and nonylphenol ethoxylates: chemicals so ubiquitous that they are found in substantial concentrations in wastewater from virtually every dyeing and finishing plant. These salts and dyeing chemicals in textile effluents tend to be difficult to remove during wastewater treatment and may contribute to failures in toxicity tests required under National Pollution Discharge Elimination System (NPDES) permit requirements. The U.S. EPA believes that test failures indicate potential environmental impact associated with the discharge of the effluent. Ultimately, test failures increase textile production costs in efforts to comply with discharge permits.
The freshwater cladoceran, Ceriodaphnia dubia, is one of the primary test organisms used to monitor permitted discharges to freshwater systems. It is sensitive to increased salinity, and toxicity test failures by textile effluents are often attributed to TDS. However, TDS is inclusive of all dissolved elements and the relative toxic contributions of the individual components are generally left undetermined. Chloride, sulfate and, to some extent, carbonate contribute to TDS in textile effluents, but may differ significantly in their individual toxicities to C. dubia. There may also be significant synergistic or antagonistic characteristics that affect their toxicities. The presence of these anions in effluents may similarly affect the toxicity of other chemicals present in textile effluents. Presently unavailable information describing the toxicities of chloride, sulfate and carbonate, possible synergistic and/or antagonistic relationships and influences on the toxicities of the other common constituents of textile effluents will be generated in this project. The knowledge gained is needed for the management of textile dyeing and finishing processes to improve water quality and reduce failures in testing required by discharge permits.
Explanation of Work Proposed
a) The textile industry has to comply with regulations of the Federal Clean Water Act (Public Law 95-217) in regards to their wastewater treatment. One requirement of many NPDES permits is periodic monitoring of effluents with C. dubia in chronic exposures. Failures of these tests result in regulatory requirements that grow increasingly costly for the textile plant with each subsequent failure. Ceriodaphnia dubia is sensitive to salinities above 1 part per thousand. However, there is often considerable variability in test results that cannot be explained by salinity alone. Wastewaters from textile manufacturing often contain high concentrations of chloride, sulfate and carbonate which contribute significantly to salinity. The relative toxicity of each component to C. dubia is different and may be additive, synergistic and/or antagonistic to the toxicity of other components. Information on the sensitivity of C. dubia to these anions both individually and in mixtures is valuable for the textile industry. For example, textile-manufacturing facilities may be able to reduce effluent toxicity by manipulating the ratios of chloride, sulfate and carbonate used in their dyeing and neutralization processes. Within acceptable limits of salinity, the effects of chloride, sulfate and carbonate may reduce toxicity of other chemicals in solution through ion competition, ion pairing and reduction of chemical activities. There are a number of organic chemicals that are fairly common to effluents of textile manufacturing. However, their toxicities in slightly saline solutions are unknown. This study will establish and compare their toxicities in freshwater and saline waters and determine if toxic effects are additive, synergistic or antagonistic with the salinity components. Combinations of chloride, sulfate and carbonate that may reduce the toxicities of these commonly used chemicals may be identified. This information could be used in the management of processes to reduce the toxicity of effluents.
b) The objectives for FY2003 include: 1) establish the chronic toxicities of chloride, sulfate and carbonate to C. dubia, 2) determine whether toxicities of chloride, sulfate and carbonate are additive, synergistic or antagonistic with one another, 3) establish the chronic toxicity of a commonly used chemical (e.g. nonylphenol ethoxylates, lignin sulfonates or naphthalene sulfonates) to C. dubia, 4) determine effects of manipulating salinity components on the toxicity of this chemical.
c) Additional work will be conducted in following years to establish the toxicity of other textile chemicals often present in textile effluents and the effects of salinity mixtures on their toxicities
d) Limited research has been conducted on the chronic toxicity of chloride, sulfate and carbonate to C. dubia. In previous work, we established an ameliorative effect of hardness to the toxicity of chloride, which suggested that effluent toxicities could be reduced simply by manipulating basic chemistry. In chronic assessments of textile effluents, we have observed significant variability in C. dubia response within similar ranges of salinity (and conductivity), which may have been attributable to differences in the concentrations of chloride, sulfate and carbonate. The ability of salinity to reduce the toxicity of other chemical stressors in aqueous solutions is well known. Quantifying the effects of salinity on chemicals common to textile effluents will produce new knowledge that can be used by the industry to avoid chronic toxicity problems in wastewater.
e) The industry partner will help identify relevant ranges of chloride, sulfate and carbonate concentrations to be evaluated and other chemicals common to textile effluents. The industry partner will meet with other members of the project team on a regular basis to review results and assist in long term planning of the project work.
Description of Technical Approach
The chronic toxicity of formulated solutions will be evaluated with 7-day, 3-brood reproduction tests using C. dubia (USEPA 1994), the standard method by which most textile effluents are evaluated under the NPDES permit requirements. Tests will be conducted at the Athens, GA laboratories of the USGS Patuxent Wildlife Research Center, which are housed by the Warnell School of Forest Resources, The University of Georgia (WSFR - UGA). These facilities are well equipped to perform the procedures required for this study and the personnel involved have conducted many assessments with this protocol and test organism. Animals used for testing will be provided from in-house cultures and exposures will be conducted in environmental chambers that will maintain constant temperature and a 16 h light/8 h dark photoperiod.
The study will first establish concentrations of chloride, sulfate and carbonate that inhibit 25, 12 and 6% of the reproduction observed in control treatments (IC25, IC12, IC6). The second phase will incorporate the IC values to determine toxic responses of C. Dubia to mixtures containing different ratios of the salinity components. A model will be created that describes the relative toxicities of chloride, sulfate and carbonate to C. dubia and their additive, synergistic or antagonistic relationships.
The toxicities of other chemicals common to textile manufacturing processes will be assessed in freshwater solutions and in solutions containing different ratios of chloride, sulfate and carbonate to evaluate effects on the toxicities of those chemicals. During the first year of the project we will concentrate on the toxicity of nonylphenol ethoxylates as influenced by salinity. Additional chemicals to be evaluated will be determined through input from cooperators within the textile industry.
Test solutions will be prepared with deionized water reconstituted with reagent-grade salts to provide moderate hardness and alkalinity with the essential elements required for C. dubia reproduction. Chemical constituents of test solutions will be analyzed in house. Basic chemistry of exposure solutions will be determined at test initiation and will include dissolved oxygen, pH, conductivity, hardness and alkalinity.
The design of this study is too large to facilitate completion in a single test and therefore will have to be separated into multiple parts. Reference toxicant tests using potassium chloride will be conducted simultaneously with every test to evaluate the consistency of C. dubia response among the multiple tests. Reference toxicant solutions will be prepared from the same moderately-hard water used for the other toxicant assessments.
The research team will disseminate the results of this study through presentations at industry meetings, workshops and conferences and through refereed professional journals.
Project Team
Professor Warren Perkins (Georgia Power Company Professor of Textile Sciences at the University of Georgia) has over 30 years experience in textile wet processing. Much of his research relates directly to water pollution abatement. His role in the project is to handle all administrative activities such as reporting and budget control, and provide overall supervision of project work, guide the selection of auxiliary chemicals for study, and assist in interpretation of data.
Professor George L. Baughman (Senior Research Textile Chemist at the University of Georgia) will be the team leader. He has over 30 years experience in analytical and environmental chemistry. His previous employers include NASA and the U. S. EPA. He has worked for many years on textile-related projects, mainly concerned with water pollution abatement. His role is to provide expertise in analytical work required in the project.
Dr. Peter J. Lasier (U.S. Geological Survey and Warnell School of Forest Resources at the University of Georgia) is an aquatic scientist with expertise in chemistry and toxicology of aquatic contaminants and assessments of aquatic systems. His involvement includes organizing and leading laboratory activities, analyzing data, summarizing results and preparing presentations and manuscripts.
Dr. Parley V. Winger (U.S. Geological Survey and Warnell School of Forest Resources at the University of Georgia) is an aquatic scientist with expertise in aquatic biology, toxicology of aquatic contaminants and assessments of aquatic systems. His involvement includes assisting with laboratory activities and contributing to the summarization and preparation of presentations and manuscripts.
Schedule
MonthsTask
1-2 Establish IC values for chloride, sulfate and carbonate to C. dubia
3-5 Determine toxicity relationships among chloride, sulfate, and carbonate
6-8 Create model describing chloride, sulfate and carbonate toxicities
8-10 Establish IC values for nonylphenol ethoxylates to C. dubia
10-12 Determine effects of chloride, sulfate, and carbonate on the toxicity of nonylphenol ethoxylates
PROJECT SUMMARY (for website)
Salinity, or total dissolved solids, is often cited as the most probable source of toxicity in textile wastewater. In addition to elevated salinity, textile effluents frequently contain high concentrations of dispersing agents and surfactants that may contribute to toxicity. The objective is to lower the incidence of failures in aquatic toxicity tests on textile wastewater by better understanding the role that salinity and common organic chemicals play in causing toxicity in textile wastewater.
