Intensification of Biodegradation with FLEXIPAK® Bioreactors in Industrial Pretreatment Plants

Imre Gyulavari, Gyula Lakatos

A pretreatment facility was established at the canning factory of EKO cPlc. in Nyíregyháza, Hungary between 2012 and 2013 for treating the highly concentrated industrial waste water generated during the processing of sweet corn. This is one of the largest canning factories in Hungary. The results and technologies used for the pretreatment of waste water generated during the main production seasons of the past 3 years are summarized, with special emphasis on CODCr and BOD5 parameters. The mass of industrial waste water was generally around 1200 m3/d or 50 m3/h generated evenly in the course of 3 shifts per day. The mechanical pretreatment phase consists of the following steps: fine screen, trommel screen, grit tank. The biological unit, developed by a Hungarian team, consists of multiphase, aerobic, submerged contact media units. The biological phase is distributed under the FLEXIPAK®-MIX brand name, while the submerged biofilm contact media unit under the TURBOPAK® brand name and both are manufactured in Hungary. These biofilm systems are collectively called System Gyulavári. The systems and models have been and still are being installed in many different structures. In the case of the EKO canning factory the concentration of raw waste water reached a maximum of as high as 13.000 mg/l CODCr and 6000-6500 mg/l BOD5 values at times. The mandatory treatment values specified for public sewer systems are: 1000 mg/l CODCr and 500 mg/l BOD5. The diameter of the FLEXIPAK®-MIX system, namely the circular steel structure, built in a ringed format, is 28 meters in total. A total of 680 m3 in-line TURBOPAK® contact-media had been built into these 2 rings marked as I. and II. forming a total of 102.000 m2 biofilm surface.

In the center of the structure a 9.0 m Ø DUALOX (System Gyulavári) ventilation unit has been installed in cells a, b, c and d joined in-line. Circular flow and supplementary O2 supply is ensured by 20 HP-Jet injector pumps which are suspended at 4 different locations resulting in 250-300 instances of contact with the biofilm for the waste water being treated on the surface of the fix contact units. Total time spent in the system is 2 days. The final complex polishing treatment is provided by the high pressure floating DAF equipment conditioned with chemicals. The results of 3 years of operation have proved the efficiency and cost effectiveness of the system. Based on organic pollutant content, the order of magnitude of the pretreatment system is 200.000 PE. From a global perspective, the system/structure is the first Hungarian patent (registered under 229.918 patent number, I. Gyulavári 2010) has ever built.