Sludge disposal and wastewater treatment in the region of Bratislava

In the process of wastewater treatment there are generated products that wastewater treatment plant operators want to eliminate. The most important product – waste generated in mechanical-biological treatment of wastewater – is sludge. Bratislava Water Company (BVS) operates three wastewater treatment plants (WWTP) with different mechanical-biological treatment technologies in the region of the Slovak capital. The total capacity of these WWTP is 1,515,000 population equivalent (p.e.). The WWTP serve the needs of about 557,000 p.e. who produce about 140,000 m³/day of wastewater. Annual production of mechanically dewatered anaerobically stabilized sludge is about 560,000 tons. At present, the biogas obtained from sludge is used for bioenergy production. The resulting thermal energy is used for technological purposes such as heating of operating premises and sludge digestion tanks. The obtained sludge is further recovered as a component in production of industrial compost or it can also be used for direct application to agricultural or forest land (if appropriate composition).