By Jon Cleveland
On the surface, this seems like an easy question; ones initial answer may be “using less chemical”. Chemistry is an expensive component to wastewater treatment to be sure, but optimizing does not necessarily mean using less, it means extracting the most benefit from each ml of chemistry dosed. It means holistically looking at the treatment regimen, and making sure each phase is controlled. Here at TTX Environmental, we take this very seriously. Here’s a real world example of the strength we bring to your chemical feed system:
A midwestern food manufacturer contacted us about working with their chemical supplier to automate their chemical feed to their DAF (Dissolved Air Floatation) system.
What we found on our site survey was that their emulsion flocculant polymer system was not functioning properly. The TSS leaving the DAF was well over their discharge limits, and that TSS was mostly fats, oils, and greases (FOG), which put them over their BOD limits as well.
On the surface, the fix was simply to get the flocculant makedown system functioning, and certainly that would have improved performance considerably, but in addition to poor makedown, we found the DAF serpentine mixer was mostly plugged, with flow restricted considerably. The coagulant feed point had been relocated too close to the flocculant injection point as well.
Fixing the serpentine, injecting the coagulant further back in the system, and getting the flocculant made down properly would certainly be a huge improvement, but was it optimization? In many ways yes, but the site survey revealed a few other issues, the next one being flow from the equalization tanks was highly erratic, the years of pumping against a slowly plugging serpentine had caused pre-mature wear to the feed pump, so it required a rebuild. With that, a constant and controllable feed rate to the DAF could be achieved. Alas, our survey indicated one last issue, that of pH. The pH of the water leaving the EQ tank was often well below the optimal for the flocculant, so pH correction needed to be included as well.
The system went from rarely functioning to generating solids that were easily removed by the DAF. Would correcting any one of these issues been an improvement? Certainly. Would correcting any one, or even many of them, resulted in optimizing the chemistry? No. In the end, more “chemical” was dosed, after all, we added a caustic feed system which wasn’t there before. But regarding the flocculant and coagulant doses, well, they certainly decreased, significantly, from 6 totes per month to 2 1/2. Most importantly, the facility was able to meet their discharge permits, and avoid surcharges and potential shutdown.
Over the coming weeks, I will be sharing other stories of getting the most from the investments made in wastewater treatment systems. There are places for rapid and easy ROI in many facilities we visit. To schedule a consultation to evaluate your specific issues, be sure to contact TTX Environmental.
Jon Cleveland currently works at Therma-Tron-X, Inc. as Sales Engineer for the Environmental division, and brings nearly 30 years of experience in instrumentation and control, highlighting his expertise in municipal and industrial water treatment. Process optimization has been a passion of his from the start. Jon looks forward to working with you to get the most out of your water treatment systems.