SOFIA MECHANICAL & BIOLOGICAL TREATMENT PLANT

Preventive maintenance of a bioreactor for organic waste processing of food waste

The challenge

Sofia’s MBT municipal waste plant is located in the village of Gorni Bogrov, near Sofia. A biological treatment plant (BT) was built on site which includes composting of biodegradable waste and composting of green waste.

The anaerobic reactor is 3600 m³ in volume and stopped functioning due to clogging with large debris thus causing a serious environmental issue for the Client. 70 % of the sludge remained in the reactor and had to be disposed of to the Sofia WWTP operated by Veolia. The Client had to find a reliable and experienced partner to safely dispose of the sludge urgently and to restart the technological functioning of the reactor without causing any risk to the environment.

Veolia’s solution

For the purpose of carrying out the maintenance, the team of Veolia Bulgaria had to install specially designed valves - compatible with the mobile equipment used for vacuum suctioning and transportation of the bioreactor’s contents. In addition, in order to scoop out the solid residue mass, another valve was installed to ensure the controlled and safe release of wastewater. 

All activities were performed in accordance with the Health & Safety requirements for working in a hazardous gaseous environment with elevated levels of hydrogen sulphide and methane.