Wastewater from civil or mix sewerage and from industrial parks
|The Microbioflottazione process can also be used for wastewater discharges from civil and mixed sewerage. Thanks to its potential and flexibility it is possible treating waste waters with high flow rate in reduced volumes with a minimum excess sludge production. The system, thanks to its technical characteristics and biological, manages to ensure constant results even in case of strong discontinuity of flow rate and load.
In some cases or when some factories with special discharges are settled in the industrial park, the system can be up or down-stream up-graded, if necessary, with specific phases for the removal of particular pollutants (i.e. oil/sand separation, ozonization, UV disinfection or chlorination, etc.).
Hereunder is reported the example of a treatment plant installed in February 2008 for wastewater from an industrial park of a city (Kuwan-Yin) in the northern part on the island of Taiwan ROC.
The plant is made up with an initial screening phase and two phases in series of Microbioflottazione followed by a phase of flotation. The flow rate treated is 20.000 mg/l, the average concentration of COD in the wastewater is 650 mg/l with a soluble fraction characterized by a very low biodegradability, in fact the BOD5 is less than 120 mg/l. Nonetheless this negative characteristic the plant is anyway able to treat biologically this kind of wastewater differently from others traditional treatment plant previously installed in the industrial park. After treatment the average outlet COD is lower than 90 mg/l.
In order to increase the COD removal more than 90% of efficiency, an up-grade of the plant with a pre-ozonization phase is under examination.