Sludge Tanks Operation in Small and Middle-Sized Waste Water Treatment Plants

Abstract

Sludge treatment in the small and middle-sized WWTPs represents a separate unit in waste water treatment. In the past years this issue did not receive proper care due to missing legislation. After Slovakia entered the EU, our country has been following the EU requirements, which have been implemented into Slovak legislation. On January 1, 2004 Act No. 188/2003 Coll. on application of treatment sludge and drain sediments into the soil came into force. It established requirements on thickened and dewatered sludge before its utilization in agriculture. The improving of building of new small and middle-sized WWTP to the year 2015 will also improve the production of treated sludge. Therefore the question of sludge solution is of high importance. We expect growing number of WWTP with sludge treatment in open sludge tanks. In our research work we have applied the description of processes which are in process in sludge tanks. We monitored operation of open sludge tanks on two WWTPs directly in the sludge objects and on models, where we simulated several treatment conditions. The objective of our work is to create requested treatment condition in sludge tank; so that the process of sludge thickening and stabilization has sufficient efficiency and treated sludge can be used according to valid Slovak legislation in other procedures.