Biological Activated Filters in Wastewater Treatment – A Useful Process for an Efficient Performance –

The biological activated filtration has been developed from conventional sewage water filter systems. Currently, bio-filters are used as biological main -, secondary - and post-treatment for degradation of organic compounds as well as for nitrification and denitrification. Within a German ATV-DVWK research project, operational data has been recorded by a questionnaire of known bio-filter operators in Germany, Austria and Switzerland. The results show that biological activated filtration leads to an improvement of wastewater treatment plant effluent quality. Furthermore, the selected data could be used to calculate the volumetric load and - degradation of COD, NH4-N and NO3-N. It becomes obvious that the volumetric degradation of bio-filters applied in different stages of the clarification process differ. This emphasizes the influence of various parameters on purification performance which makes the process controllable by dosage of external carbon source and supply of process air.