Disposal alternative Advantages Disadvantages
Incineration
Drastic volume reduction Sterilization Energetic valorization of sludges Low sensitivity to sludge composition Minimization of odors, due to closed systems and high temperature High costs Ash disposal Atmospheric pollution
Landfill disposal
Low cost Problems with locations near urban centers Gas and landfill leachate production Difficulty in reintegrating the area after decommissioning Requirement of large areas Requirement of special soil characteristics
Thermal drying
Total destruction of organic matter and total mineralization of sewage sludge The possibility of burning both stabilized and unstable sewage sludge Up to 10-fold reduction of sludge volume Energy recovery No odor emission Large investment cost, high operating costs Energy consumption of the installation The necessity of using pre-dried, dehydrated sediments; Emission of dusts, gases (SOx, NOx, HCL, HF) The need to store the resulting ashes
Composting
The possibility of burning both stabilized and unstable sewage sludge Sewage sludge mass and volume reduction Sludge water content reduction The product can be used as a fertilizer as it contains nitrogen, phosphorus, potassium, and microelements, and it improves soil properties Easy operation of the installation Windrow and aerated static pile composting require relatively large areas, and odor control is a common problem Ambient temperatures and weather conditions influence windrow and aerated static pile composting In-vessel reactors have limited flexibility to handle changing conditions and are maintenance intensive
Agricultural reuse
Large area availability Potential as a fertilizer Positive effects for the soil Positive outcome for the crops Long-term solution Contamination of the soil by metals Odors Limitations regarding composition and application rates Food contamination with toxic elements and pathogenic