Chlorinating Filamentous Bacteria
WHY YOU MAY HESITATE TO CHLORINATE FOR FILAMENT CONTROL?
TRIED IT BEFORE AND GOT NO POSITIVE RESULTS. UNDERDONE!
TRIED IT BEFORE AND THINGS GOT WORSE. OVERDONE!
YOUR FELLOW WASTEWATER TREATERS SCARED YOU OFF. NOT DONE!
COMMON CAUSES FOR THE ABOVE:
- Lack of focus on the problem. By that we mean a microscopic level focus.
- Lack of bioaugmentation (reseeding) before, during and after the process.
- Lack of experience implementing chlorination programs
Chlorination is intended to cause filament damage, breaking the bacterial threads that cause interfloc bridging and poor settling. One can only see if this is happening, and to what extent via routine microscopic examination of the biomass.
You can start at a low chlorine dosage. Most literature suggest starting with 2-3 lbs. CL/1000 lbs. of MLVSS if applying to the RAS flow. This varies greatly. If the micro examination does not show filament damage, you know you can, and probably need to increase the dosage. Do this in measured increments until the filament damage is observed and long enough to achieve SVI improvement. Monitoring the process under the microscope eliminates a ride on the overdone, underdone and not done seesaw.
REASONS FOR AND THE VALUE OF THE CHLORINATE AND RESEED APPROACH
Filaments are present in the biomass because they thrive on the organic substrates in the wastewater and or the operating conditions. In other words they are good BOD removers and therefore, good workers in that sense. Problem is, in sufficient amounts they don’t settle well.
So, if you are killing filaments to improve settling, you are also killing your BOD removal workers. Worst case, this could cause organic breakthrough and effluent compliance problems.
The way to eliminate this situation and the worry is to replace the workers you want to harm with floc forming bacteria. We recommend to start seeding before chlorination as some portion of the floc will be negatively impacted as well. Seeding during chlorination insures BOD compliance and will give the floc formers a head start to outcompete the filaments. The positive results will begin sooner and last longer.
When you get where you want to go, it is best to waste out the trash created through filament damage. It is now nonperforming biomass and should be wasted out of the system. Seeding during this phase of increased wasting rates again assures BOD removal and promotes floc former dominance over filament return.
Bacterial seeding as part of the filament chlorination process produces a more predictable, faster, longer lasting and safer result.
Pending your needs, we offer our experienced chlorination application supervision, in addition to a specific ProKa microbial formulation (or the BioG technology) for a highly effective reseed/chlorinate program.