Micro screening in wastewater treatment – an overview
Microscreens, or microstrainers, are widely used within wastewater treatment, and applications include primary and tertiary treatment as well as treatment of stormwater. The following paper is an attempt to present an overview of literature in order to identify possibilities and key questions associated with two types of microscreens based on gravity flow – disc- and drumfilters. Generally there is a good foundation based on practical experience, especially for tertiary treatment. The particle size distribution and floc strength are identified as crucial parameters in understanding and design of microscreens. Difficulties in applying chemical pre-treatment and clogging of filter media are described as drawbacks but also as key questions for further development of the technology.