SIZING OF WASTEWATER SLUDGE ANAEROBIC DIGESTERS

摘要

The necessity of a new approach to design (bioreactors' volumes sizing) of the municipal wastewater sludge digesters motivates the research reported in this paper and the main reasons for this are discussed. The proposed model is founded on the kinetics of the relevant physical and biological processes (the later taken in lump) and needs only few basic sludge quality parameters as input. It allows positioning of the designed digesting system in an arbitrary study-state, motivated according to the local environment (hygienic) and economical requirements and conditions. Considerations of the different rates of aerobic and anaerobic digestion of primary, waste activated and mixed sludge, along with the relevant hydrodynamic conditions and processes of thickening taking place in some anaerobic digesters, are among the unique features and main advantages of the model. The software package STAB, which is based on the proposed model, proved to be a useful tool not only for design but also for various technical and economic investigations concerning determination of the optimal technological scheme and degree of municipal waste-water sludge stabilisation, and costs minimisation.