MODLING WWTP - TREATMENT EFFICIENCY AND RELATIONSHIP TO RECEIVING WATER-QUALITY

The relationship between water protection of small receiving waters an d the reliability of treatment efficiency is represented by a 100,000 PE plant. On the basis of stringent emission and immission standards a concept for a one-stage activated sludge plant was developed that mee ts the current demands on removal efficiency and limit values in Austr ia with a high degree of reliability. Classic saprobiological analysis of the receiving creek showed saprobic class II. The operation of the treatment plant has been tested in a period of more than two years un der normal operational conditions. In this period several modes of ope ration were investigated and the concept has proved to be successful. A comprehensive data base has been worked up for process comparison an d design evaluation. Relevant effluent parameters of a filtration unit in pilot scale are also given. Mass balances for a validation of the data and statistical characterisation of treatment efficiency combined with saprobiological characterisation of the receiving river has prov ed the applicability to similar cases. These investigations may serve as an example of how to relate treatment efficiency to saprobity of sm all receiving rivers. Copyright (C) 1996 IAWQ. Published by Elsevier S cience Ltd.