Challenge
Reusing the existing wastewater treatment system posed many challenges for Sazerac. Poor settleability of the anaerobic solids significantly limited the solids loading rate on the clarifier, which subsequently limited the mixed liquor suspended solids concentration in the complete-mix anaerobic reactor. With a limited solids inventory in the anaerobic reactor and persistent operator attention required to maintain adequate effluent quality, wastewater flows to the treatment plant were significantly restricted.
The vast majority of wastewater generated from NOD needed to be hauled away at a significant expense to the plant. This approach to wastewater treatment was deemed unsustainable, so Sazerac invested in an upgrade the wastewater treatment plant.
Solution
Converting the existing anaerobic reactor to an anaerobic membrane bioreactor (AnMBR) system by pairing the complete-mix reactor with skids of external cross-flow ultrafiltration membranes.
Results
By consistently generating final effluent with very low BOD and negligible TSS concentrations, the membranes improved final effluent quality being discharged to the municipal treatment plant. The conversion to an AnMBR system effectively increased the hydraulic and organic loading treatment capacity of the system, without having to add any additional anaerobic reactor tanks, which helped to minimize capital expenditures associated with the treatment plant upgrade.
Conclusion
The upgrade to AnMBR solved all previous challenges with previous wastewater treatment plant.
- Membranes provide complete solids-liquid separation and biomass retention, and elimate the need for the clarifier
- Consistently generates final effluent with very low COD, BOD and negligible TSS concentrations
- Membranes eliminate the restriction on anaerobic reactor solids inventory - previously in place due to the clarifier
- Conversion to an AnMBR system effectively increases the hydraulic and organic loading capacity of the system, without having to add any additional anaerobic reactor tanks
