MECHANICAL PRE-TREATMENT STAGES OF MUNICIPAL MBR APPLICATIONS IN GERMANY - CURRENT STATUS AND TREATMENT EFFICIENCY

INTRODUCTION Screening normally is the first mechanical treatment step at the headworks of any wwtp employing vertical slit geometries usually ranging from large through middle gap sizes. Performances of screening systems, single staged or multi staged, or on occasion fine screens (sieves) differing in type of construction, gap geometry and gap size are absolutely reliable and that's why till today screening or sieving was not focused as a main investigation or research topic. There are only small hints (Schier and Frechen, 2004) to be found in literature where efficiency of screens and particularly sieves applied in municipal wastewater treatment is described.