Hans Kupfer & Sohn GmbH & Co. KG (Heilsbronn, Germany), a large meat processor in the German state of Bavaria, had an onsite wastewater treatment system that included mechanical screening, flotation, and biological treatment. The company had expanded its production facilities over the years but not the treatment system. Eventually, the system began repeatedly exceeding its discharge limits. Furthermore, the effluent is discharged into a small creek that can barely handle peak loads.
The company hired a project team to plan a new, state-of-the-art wastewater treatment system. The team selected a membrane bioreactor (MBR) because it has a small footprint, removes 100% of suspended solids, and provides reusable effluent.

After initial startup, the full-scale MBR has consistently complied with all discharge requirements. Since March 2008, the MBR plant has consistently met its permitted limits and has since begun discharging directly into the creek.
However, the permeate meets reuse quality standards. COD averages about 20 mg/L, which is considerably less than the required permit value (75 mg/L).
Likewise, ammonia, nitrogen, and phosphorus are well within limits. Also, the permeate is free of suspended solids — the main reason why it is suitable for reuse.

This is an abridged version of the article from the "Industrial Wastewater" magazine in December 2008/January 2009. You may download the complete, detailed article following the link presented below: