More Floc
Question: Steve, in your March 2003 “Increased Floc” article, you responded to a reader’s question regarding increasing amount of floc in the wastewater pretreatment clarifier even though “nothing in our operations or chemistries has changed...” Chances are that something did indeed change, and detective work is needed to find the culprit.
Question:
Steve, in your March 2003 “Increased Floc” article, you responded to a reader’s question regarding increasing amount of floc in the wastewater pretreatment clarifier even though “nothing in our operations or chemistries has changed...” Chances are that something did indeed change, and detective work is needed to find the culprit. Let me tell you about an experience several years ago. Just like S.T., we were seeing higher solids in our clarifier, sometimes causing non-compliance. Of course, initially the process line and wastewater operators responded, “nothing has changed.”
We did not accept these responses at face value. After much detective work, we found the culprit, excessive dosage of anionic polymer. Due to equipment failure, the anionic polymer was continuing to be fed into the system even when no wastewater was being fed to the system. Once this was corrected and the polymer dosage returned to its target value, the amount of floc and metals in the clarifier’s effluent dropped back to historical levels. D.E.
Answer:
Thanks D.E. This is another example that with many wastewater pretreatment chemistries “more is NOT necessarily better,” in fact, “more is bad.” I am sure your experience will help others.
Related Content
-
Zinc Phosphate: Questions and Answers
Our experts share specific questions about zinc phosphate and pretreatment
-
NASF/AESF Foundation Research Project #122: Electrochemical Approaches to Treatment of PFAS in Plating Wastewater - 12th Quarterly Report
This NASF-AESF Foundation research project report covers the 12th quarter of project work (October – December 2023) at the University of Georgia. In our previous report, we described our work on performance and effect of surface fluorinated Ti4O7 anodes on PFAS degradation in reactive electrochemical membrane (REM) mode. This quarter, our experiments involved utilizing porous Ti4O7 plates serving both as anodes and membranes. Tests compared pristine and F-18.6 Ti4O7 anodes at current densities of 10 mA/cm2 and 40 mA/cm2. This 12th quarterly report discusses the mechanisms of the effects on EO performance by anode surface fluorination.
-
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.
