Final Report: Development of Electrochemical Processes for Improved Treatment of Lead WastesEPA Grant Number: R825549C035
Subproject: this is subproject number 035 , established and managed by the Center Director under grant R825549
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: HSRC (1989) - Great Plains/Rocky Mountain HSRC
Center Director: Erickson, Larry E.
Title: Development of Electrochemical Processes for Improved Treatment of Lead Wastes
Investigators: OKeefe, Thomas J. , Watson, John L.
Institution: Missouri University of Science and Technology
EPA Project Officer: Hahn, Intaek
Project Period: January 1, 1991 through January 1, 1993
Project Amount: Refer to main center abstract for funding details.
RFA: Hazardous Substance Research Centers - HSRC (1989) RFA Text | Recipients Lists
Research Category: Heavy Metal Contamination of Soil/Water , Land and Waste Management
Objective:The research aim of this project was to assist in developing auxiliary electrochemical processing technology to allow the successful treatment of the solid wastes containing Pb as one of the primary contaminants. Specifically, the work was directed toward identifying the role of the PbO2 anode, and the chemical components needed to catalyze oxygen evolution from it, during Pb electrowinning. Characterizing the various anodes and establishing reference base polarization curves for the competing systems was the major goal accomplished by this study.
The performance and behavior of the anode is important for the electrometallurgical treatment of lead wastes, particularly battery residues. The investigation is directed toward the essential features that must be maintained to have an efficient viable electrowinning process to recover metals such as zinc and lead.
The basic processes for Pb electrowinning from wastes have been developed by the U.S. Bureau of Mines and RSR Corporation of Dallas, Texas. Engitec Corporation of Milan, Italy has a commercial process available as well. Each of these organizations supplied technical and/or financial support to the research and were directly involved in the organization and direction of the work to insure relevance and ultimate utilization of the results. Materials were provided by the collaborating groups, since each has a slightly different anode construction and catalytic component. Phosphorus is used by the U.S. Bureau of Mines and arsenic by RSR Corporation, while Engitec has employed a variety of catalysts. In the former case, only PbO2 anodes were supplied, whereas Dr. Olper of Engitec provided a platinum coated electrode in addition.
The experimental procedures employed during this research included techniques and characterizations commonly used in electrochemical research. Cyclic voltammetry, AC impedance spectrometry, scanning electron microscopy (SEM), Auger and ESCA analyses, as well as standard galvanostatic cell processing were employed and found to be very useful in characterizing the system.
Process Description - Lead Electrowinning
A number of technically innovative processes have been described in the patents as well as in professional journals. The process patented by the U.S.B.M. entitled "Electrolytical Method for Recovery of Lead From Scrap Batteries," E.R. Cole, A.Y. Lee, and D.L. Paulson, No. 4,272,340 assigned to the U.S. Department of Interior was chosen as the model upon which the proposed process is based. The U.S.B.M. technology is essentially a hydrofluorosilicic (H2SiF6) leach of lead oxide. A number of modification and improvements have been made, but the fundamental chemistry and electrochemistry of the leach-electrowin steps remain. Since this technology forms the backbone of the work proposed, it was chosen as the primary system investigated.
Galvanic Stripping of Organic Solvents
The other primary focus of the research involved the development of a new and unique solvent extraction process as a potential method to treat lead wastes. For the initial portions of the work, di-ethyl hexyl phosphoric acid in kerosene was used. The process concerns the use of solid metals to galvanically strip metal ions such as lead from the organic. The results obtained were very good and considerable interest has been shown by a number of companies regarding applications.
Results showed that a non-porous lead dioxide coating deposited from lead nitrate electrolyte on- titanium substrates had b-PbO2 as the dominant phase and a-PbO2 as the minor phase. An increase in the pH from -0.2 to 4 improved the adherence to the substrate and the additive SLS (sodium lauryl sulfate) refined the faceted structure and decreased in the growth of the a-PbO2 modification. A low acid nitrate electrolyte with sodium lauryl sulfate was therefore the preferred electrolyte. Lead fluoborate electrolyte with animal glue as additive resulted in a non-porous lead dioxide deposit with a finely faceted morphology consisting only of b-PbO2. A cloth covering the graphite substrate changed the surface structure with non-faceted grains or even an amorphous looking structure being observed. The lead dioxide plated from lead fluoborate was less brittle than if plated from lead nitrate but was polarized in lead fluosilicate compared to the lead dioxide plated from high acid lead nitrate. The absence of a-PbO2 in its composition was assumed to cause this polarized behavior. Lead dioxide plated from lead fluosilicate on graphite was glossy and very brittle and appeared to be partially amorphous. The polarization behavior of PbO2 anodes plated from lead nitrate electrolytes was strongly influenced by the acid concentration used in their production.
In summary, it seems that the process used to plate the lead dioxide may influence the structural and electrochemical properties of the anodes. Proper characterization of the films would appear to be an essential element of any lead electrowinning process if proper performance is to be obtained.
This research has been conducted in cooperation with the U.S. Bureau of Mines and industrial companies. The results have been communicated to the cooperating organizations and others.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
|Other subproject views:||All 2 publications||1 publications in selected types||All 1 journal articles|
|Other center views:||All 904 publications||230 publications in selected types||All 182 journal articles|
||Bemelmans C, O'Keefe T, Cole E. Evaluation of electrodeposited lead dioxide. Bulletin of Electrochemistry 1996;12(10):591-596.||
Supplemental Keywords:lead, zinc, electrowinning, anode polarization., Scientific Discipline, Water, Waste, Ecosystem Protection/Environmental Exposure & Risk, Contaminated Sediments, Environmental Chemistry, Geochemistry, Remediation, Analytical Chemistry, Fate & Transport, Ecology and Ecosystems, electrokinetics, fate and transport, electrowinning, contaminant transport, biodegradation, contaminated sediment, lead, metals recovery, scanning electron microscopy, electrochemistry, contaminated soil, bioremediation of soils, chemical kinetics, heavy metal contamination, heavy metals
Progress and Final Reports:Original Abstract
Main Center Abstract and Reports:R825549 HSRC (1989) - Great Plains/Rocky Mountain HSRC
Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R825549C006 Fate of Trichloroethylene (TCE) in Plant/Soil Systems
R825549C007 Experimental Study of Stabilization/Solidification of Hazardous Wastes
R825549C008 Modeling Dissolved Oxygen, Nitrate and Pesticide Contamination in the Subsurface Environment
R825549C009 Vadose Zone Decontamination by Air Venting
R825549C010 Thermochemical Treatment of Hazardous Wastes
R825549C011 Development, Characterization and Evaluation of Adsorbent Regeneration Processes for Treament of Hazardous Waste
R825549C012 Computer Method to Estimate Safe Level Water Quality Concentrations for Organic Chemicals
R825549C013 Removal of Nitrogenous Pesticides from Rural Well-Water Supplies by Enzymatic Ozonation Process
R825549C014 The Characterization and Treatment of Hazardous Materials from Metal/Mineral Processing Wastes
R825549C015 Adsorption of Hazardous Substances onto Soil Constituents
R825549C016 Reclamation of Metal and Mining Contaminated Superfund Sites using Sewage Sludge/Fly Ash Amendment
R825549C017 Metal Recovery and Reuse Using an Integrated Vermiculite Ion Exchange - Acid Recovery System
R825549C018 Removal of Heavy Metals from Hazardous Wastes by Protein Complexation for their Ultimate Recovery and Reuse
R825549C019 Development of In-situ Biodegradation Technology
R825549C020 Migration and Biodegradation of Pentachlorophenol in Soil Environment
R825549C021 Deep-Rooted Poplar Trees as an Innovative Treatment Technology for Pesticide and Toxic Organics Removal from Soil and Groundwater
R825549C022 In-situ Soil and Aquifer Decontaminaiton using Hydrogen Peroxide and Fenton's Reagent
R825549C023 Simulation of Three-Dimensional Transport of Hazardous Chemicals in Heterogeneous Soil Cores Using X-ray Computed Tomography
R825549C024 The Response of Natural Groundwater Bacteria to Groundwater Contamination by Gasoline in a Karst Region
R825549C025 An Electrochemical Method for Acid Mine Drainage Remediation and Metals Recovery
R825549C026 Sulfide Size and Morphology Identificaiton for Remediation of Acid Producing Mine Wastes
R825549C027 Heavy Metals Removal from Dilute Aqueous Solutions using Biopolymers
R825549C028 Neutron Activation Analysis for Heavy Metal Contaminants in the Environment
R825549C029 Reducing Heavy Metal Availability to Perennial Grasses and Row-Crops Grown on Contaminated Soils and Mine Spoils
R825549C030 Alachlor and Atrazine Losses from Runoff and Erosion in the Blue River Basin
R825549C031 Biodetoxification of Mixed Solid and Hazardous Wastes by Staged Anaerobic Fermentation Conducted at Separate Redox and pH Environments
R825549C032 Time Dependent Movement of Dioxin and Related Compounds in Soil
R825549C033 Impact of Soil Microflora on Revegetation Efforts in Southeast Kansas
R825549C034 Modeling the use of Plants in Remediation of Soil and Groundwater Contaminated by Hazardous Organic Substances
R825549C035 Development of Electrochemical Processes for Improved Treatment of Lead Wastes
R825549C036 Innovative Treatment and Bank Stabilization of Metals-Contaminated Soils and Tailings along Whitewood Creek, South Dakota
R825549C037 Formation and Transformation of Pesticide Degradation Products Under Various Electron Acceptor Conditions
R825549C038 The Effect of Redox Conditions on Transformations of Carbon Tetrachloride
R825549C039 Remediation of Soil Contaminated with an Organic Phase
R825549C040 Intelligent Process Design and Control for the Minimization of Waste Production and Treatment of Hazardous Waste
R825549C041 Heavy Metals Removal from Contaminated Water Solutions
R825549C042 Metals Soil Pollution and Vegetative Remediation
R825549C043 Fate and Transport of Munitions Residues in Contaminated Soil
R825549C044 The Role of Metallic Iron in the Biotransformation of Chlorinated Xenobiotics
R825549C045 Use of Vegetation to Enhance Bioremediation of Surface Soils Contaminated with Pesticide Wastes
R825549C046 Fate and Transport of Heavy Metals and Radionuclides in Soil: The Impacts of Vegetation
R825549C047 Vegetative Interceptor Zones for Containment of Heavy Metal Pollutants
R825549C048 Acid-Producing Metalliferous Waste Reclamation by Material Reprocessing and Vegetative Stabilization
R825549C049 Laboratory and Field Evaluation of Upward Mobilization and Photodegradation of Polychlorinated Dibenzo-P-Dioxins and Furans in Soil
R825549C050 Evaluation of Biosparging Performance and Process Fundamentals for Site Remediation
R825549C051 Field Scale Bioremediation: Relationship of Parent Compound Disappearance to Humification, Mineralization, Leaching, Volatilization of Transformaiton Intermediates
R825549C052 Chelating Extraction of Heavy Metals from Contaminated Soils
R825549C053 Application of Anaerobic and Multiple-Electron-Acceptor Bioremediation to Chlorinated Aliphatic Subsurface Contamination
R825549C054 Application of PGNAA Remote Sensing Methods to Real-Time, Non-Intrusive Determination of Contaminant Profiles in Soils
R825549C055 Design and Development of an Innovative Industrial Scale Process to Economically Treat Waste Zinc Residues
R825549C056 Remediation of Soils Contaminated with Wood-Treatment Chemicals (PCP and Creosote)
R825549C057 Effects of Surfactants on the Bioavailability and Biodegradation of Contaminants in Soils
R825549C058 Contaminant Binding to the Humin Fraction of Soil Organic Matter
R825549C059 Identifying Ground-Water Threats from Improperly Abandoned Boreholes
R825549C060 Uptake of BTEX Compounds by Hybrid Poplar Trees in Hazardous Waste Remediation
R825549C061 Biofilm Barriers for Waste Containment
R825549C062 Plant Assisted Remediation of Soil and Groundwater Contaminated by Hazardous Organic Substances: Experimental and Modeling Studies
R825549C063 Extension of Laboratory Validated Treatment and Remediation Technologies to Field Problems in Aquifer Soil and Water Contamination by Organic Waste Chemicals