Untersuchungen uber die Entnahme-wirksamkeit der Fibrotexfiltration fur Cryptosporidium-Oozysten aus trubstoff-armem Wasser nach Flockenfiltration

Fine-filtration techniques may be applied as an additional step after the common treatment by flocculation and filtration to enhance the removal of parasites. As an alternative to membrane technology Fibrotex® filtration appears to being a useful means to retain the Cryptosporidium-oocysts of 5 μm in size. The method uses backwashable fibrous filter elements from Nylon® yarn which are compressed during filtration and expanded during backwash. Trials with inactivated oocysts spiked to the filtrate of a treatment plant achieved a 99% removal. Besides these tests problems are explained and discussed that occur with dosing and determination of the oocysts, and which must be cared for when evaluating the performance of technical processes.