Grantee Research Project Results
1999 Progress Report: In Process Contaminant Removal from Chromium Electroplating Baths Using a Fuel Cell Electrode Ion Exchange Membrane Process
EPA Grant Number: R827125Title: In Process Contaminant Removal from Chromium Electroplating Baths Using a Fuel Cell Electrode Ion Exchange Membrane Process
Investigators: Chang, H. Ted , Schrodt, Ariel G. , Ahmed, M. I. , Holsen, Thomas M. , Selman, J. Robert , Smotkin, Eugene S. , Donepudi, V. S. , Huang, Kuo-Lin
Current Investigators: Khalili, N. R. , Kwiecien, Malgorzata , Schrodt, Ariel G. , Ahmed, M. I. , Holsen, Thomas M. , Selman, J. Robert , Donepudi, V. S. , Huang, Kuo-Lin , Kizilel, Riza
Institution: Illinois Institute of Technology , Clarkson University
EPA Project Officer: Hahn, Intaek
Project Period: October 1, 1998 through September 30, 2001
Project Period Covered by this Report: October 1, 1998 through September 30, 1999
Project Amount: $331,389
RFA: Exploratory Research - Environmental Engineering (1998) RFA Text | Recipients Lists
Research Category: Safer Chemicals , Sustainable and Healthy Communities , Land and Waste Management
Objective:
The objectives of this project are to: (1) design, construct, and test a bench-scale fuel cell electrode ion exchange membrane process (FCMP) to remove contaminants from chromium plating solutions, (2) field test the FCMP in an operating plating shop, and (3) develop a detailed mathematical working model to optimize the process.
Progress Summary:
The project, corresponding to the three objectives stated above, is divided into three distinct tasks. The progress summary and accomplishments in each task during the reporting period are described below.
Task 1a: Design, Construct, and Test a Bench-Scale Fuel Cell Electrode Ion Exchange Membrane Process. At the Illinois Institute of Technology (IIT), the experimental cell was designed and tested under simulated plating solution conditions. Preliminary experiments confirmed the feasibility of this process as designed. Investigation of the process components was carried out as follows:
1. Ion transport through Nafion was studied by cation uptake measurements, porosity and water content measurements, x-ray diffraction analyses and equivalent weight measurements, and analyses of cation/anion dependent structural behavior. Results of these studies indicated a limiting behavior of Nafion.
2. Fuel cell oxygen electrode performance was studied by: (1) obtaining polarization curves, (2) potential monitoring during experiments, (3) acquiring x-ray diffraction patterns of new and used backing and catalyst, and (4) using alternating current impedance spectroscopy procedures.
3. The experiments were conducted at various current densities, initial concentrations, and catholyte to anolyte volume ratios. The results confirmed the feasibility of operating at higher current densities for concentrating impurities; however, initial concentration did not significantly impact removal rates due to the constant co-ion rejection in the presence of abundant counter-ions. Overall, the energy consumption was lower than for other processes using conventional metal electrodes or using gas diffusion electrodes as anodes.
Task 1b: Determination of Diffusion Coefficients and Transference Numbers of Species Across Nafion 117 Membrane. The primary work in the first year of this project at Clarkson University was to determine the partition and diffusion coefficients of the common metallic impurities Cu(II), Ni(II), Fe(III), and Cr(III) found in hard-chrome electroplating baths. According to a study of bisulfate-ion diffusion, it is very probable that anions also diffuse through Nafion membrane; therefore, the partitioning and diffusion of anions also was investigated. The objectives of this part of the project include the following: (1) determining partition coefficients of Cu(II), Fe(II), Ni(II), and Cr(III) baths with Nafion membranes; (2) determining diffusion coefficients of Cu(II), Fe(II), Ni(II), and Cr(III) through Nafion membranes; (3) determining partition coefficients of anions associated with metallic impurities in baths with Nafion membranes; (4) determining diffusion coefficients of anions associated with metallic impurities through Nafion membranes; and (5) developing a model of cation and anion diffusion through Nafion membrane.
The partition coefficients of single cations (Cu(II), Ni(II), and Fe(III)) and anions (bisulfate and bichromate) have been experimentally determined. In addition, the diffusion coefficients of each cation and anion also were obtained. These parameters are potentially quite useful for the modeling of ion transport, as the single cation modeling results show good agreement with the observed data. The next important task is to determine the diffusion coefficients during multicomponent diffusion to more closely simulate the conditions in a real chromium-electroplating bath. Multicomponent diffusion also will be modeled. Task 2: Field Trials. The scale-up of FCMP-based cells and field trials is scheduled to begin during the second year of this project. Meanwhile, some limited trials were conducted using a porous ceramic membrane cell (PCMC). These trials were done in collaboration with Dover Industrial Chrome, Inc., Chicago, IL, which provided in-kind resources. A working hard chromium plating tank containing trivalent chromium, iron, nickel, zinc, and copper as impurities was used. The results of these limited trials will be used as baseline data for comparison during future trials.
Task 3: Modeling. A phenomenological mathematical model that includes mass and ion transfer (diffusion, migration, and convection) across a Nafion 117 membrane was developed at IIT and a diffusion model was developed at Clarkson University. Model verification is pending at IIT and the diffusion model developed at Clarkson University has been applied to verify the experimental results.
Future Activities:
Task 1. At IIT, work will be continued in the following directions: (1) use of novel oxygen reduction catalysts having improved oxygen reduction kinetics, (2) verification of the phenomenological model using energy efficiency data, and (3) cell scale-up for field trials. At Clarkson University, future activities include: (1) diffusion experiments with multiple metals in solution, (2) study of the effects of temperature on diffusion and partition coefficients, (3) determination of transport numbers for the ions of interest, and (4) determination of transport properties in ceramic membranes.
Task 2. Continue field trials with a ceramic pot as well as with scaled-up cells at Dover Industrial Chrome, Inc.
Task 3. Mathematical model improvements will continue at both IIT and Clarkson University to fit the experimental data and to optimize the experimental parameters to be used in cell design.
Journal Articles:
No journal articles submitted with this report: View all 5 publications for this projectSupplemental Keywords:
chemical transport, waste reduction, treatment, environmental- electrochemical engineering, analytical and electrochemical methods, monitoring and modeling, chromium plating., Industry Sectors, Scientific Discipline, Air, Sustainable Industry/Business, POLLUTION PREVENTION, cleaner production/pollution prevention, Environmental Chemistry, Manufacturing - NAIC 31-33, Energy, Engineering, Engineering, Chemistry, & Physics, cleaner production, environmentally conscious manufacturing, electroplating, fuel cell electrode, membrane reactors, energy efficiency, ion plating, contaminant removal, mathematical formulations, metal plating, heavy metals, chromium electroplating baths, ion exchangeRelevant Websites:
http://orca.ocean.washington.edu/
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.