Die Bestimmung der Luftkeimzahl an abwassertechnischen Anlagen

Comparative measurements were carried out within the framework of the presented investigation to develop a standardised method for personal and static sampling which suits the special conditions in and on the premises of sewage plants. In fact, the central problem is the high humidity of the environment to be investigated: The use of gelatine filters, utilised for comparable measurements in the foodstuff industry and in hospitals, is impossible, because this filter type would swell during sampling, thus producing a change in the separation characteristics. The paper presents three sampling methods enabling personal and static measurements under the described framework conditions. The investigations were carried out both in a municipal sewage plant and at a laboratory sewage treatment station at places and during operational cycles of a particularly high germination index. The measuring results permit no representative statement concerning the concrete exposure of workers in these work