Method to upgrade sewage treatment plants overloaded in continuous operation

摘要

A method to upgrade existing sewage treatment plants which become overloaded in long-term continuous operation by passing waste water or a part stream thereof through a filter device which is installed additionally prior and/or subsequent to at least one overloaded stage of the treatment plant. Thus method replaces preclarification, clearing, thickening and sludge dehydration steps for a part of waste water to be treated and also a part of the biological degradation by a simple purification process using the separated solids as an alluvial filter layer. A sewage treatment plant for waste water treatment by said method is described.