Reusing Water
We are using ion exchange treatment for wastewater from nickel-chrome and zinc plating. The metal rinses are passed through the ion exchange process to remove the presence of nickel, hex chrome and zinc metal ions. The “clean water” is re-used to rinse our plated parts, but we find that it attacks the bright zinc finish. What kind of characterization do we need to do to identify the pollutants that cause this?
Q. We are using ion exchange treatment for wastewater from nickel-chrome and zinc plating. The metal rinses are passed through the ion exchange process to remove the presence of nickel, hex chrome and zinc metal ions. The “clean water” is re-used to rinse our plated parts, but we find that it attacks the bright zinc finish. What kind of characterization do we need to do to identify the pollutants that cause this? S.P.
A. I do not have enough information to give you a completely satisfactory answer, but there are a couple of things you might look at. I would start by checking the heavy metal content of your clean water after it is passed through your ion exchange system. I would also check the pH of this water to determine if it is highly acidic. Certain types of zinc plating baths are sensitive to chromium contamination.
Other pieces of information that would be helpful in answering your question include the type of zinc plating bath you are using, and whether you see this problem before or after you have performed the chemical conversion process on your parts.
Related Content
-
NASF/AESF Foundation Research Project #121: Development of a Sustainability Metrics System and a Technical Solution Method for Sustainable Metal Finishing - 15th Quarterly Report
This NASF-AESF Foundation research project report covers the twelfth quarter of project work (October-December 2023) at Wayne State University in Detroit. In this period, our main effort focused on the development of a set of Digital Twins (DTs) using the Physics-Informed Neural Network (PINN) technology with application on parts rinsing simulation.
-
NASF/AESF Foundation Research Project #120: Electrochemical Destruction of Perfluorooctanesulfonate in Electroplating Wastewaters - April 2022-March 2023
This NASF-AESF Foundation research project report covers project work from April 2022 to March 2023 at the University of Illinois at Chicago. The overall objective of this work is to utilize a cost-effective reactive electrochemical membrane (REM) for the removal of PFAS from synthetic electroplating wastewater. Initial results for the oxidation of PFOA with three different catalysts are discussed.
-
Explore Cleaning Chemistry, Metal Finishing Applications and Wastewater Treatment Solutions
Hubbard-Hall Celebrating 175 years of excellence, Hubbard-Hall presents chemistry and equipment.