What after the construction of the wastewater treatment plant: How will gases, odors... be controlled?

The capacities of the wastewater treatment plant that is to be built in Botun will be able to be expanded depending on the need, for now the maximum capacity is 230 thousand inhabitants, Branka Knežević from the Secretariat for Spatial Planning and Sustainable Development of the Capital City, a biologist by profession, pointed out in Boje jutra.

What is most controversial in the public opinion is the sludge treatment plant and incinerator. What technology will be used, what filters will be used and will they be sufficient, and what is the risk of pollution?

"Sludge incineration is permitted in European Union member states, but of course with the definition and application of strict measures. Germany, Austria, Belgium, and the Netherlands are examples of countries dominated by this technology, which involves incinerating sludge in a percentage higher than 50, and perhaps even 60 percent on average, I repeat, with the application of strictly defined measures that also characterize our plant. Why was this technology chosen? Because it is multi-effective, because it reduces the amount of sludge, or the space needed for its disposal, which is one less risk, because we get electricity that can be used, meaning energy efficiency, which is also one of the globally important topics at all levels, and because in this way, in a sustainable way, harmful substances are eliminated by incineration at high temperatures and prevented from reaching segments of the environment," said Knežević.

She also explained how to treat unpleasant odors.

"The main sources of unpleasant odors when it comes to this plant can be wastewater pretreatment units and sludge treatment units. These are systems that are located in closed buildings and are directly connected to biofilter units for the removal of unpleasant odors. What does this mean? Removal is carried out for the treatment of unpleasant odors. The treatment is carried out on two levels. First, the air that is burdened with unpleasant odors is washed, by removing the key particles that cause these odors, and then additional purification is carried out on biofilters based on organic humus. In this way, the air that reaches the atmosphere is freed from unpleasant odors. In addition to this, a mechanism will be installed that includes odor analyzers, so that we will have real-time information about the situation and what will enable us to react in the event of any unacceptable deviations. When it comes to incineration of sewage sludge, the system in which the incineration will take place is completely closed, the chimney has been designed to be adapted to this technology in terms of its height and other dimensions, and it is very important to emphasize that only "The plant has integrated filters for flue gas purification, in which purification is again performed at two levels, so that the air that enters the atmosphere after combustion is fully in accordance with our legislation, which is very strict and harmonized, since this is also one of the issues that is often mentioned, general environmental legislation is harmonized with European Union directives. In addition to the flue gas purification filter, the system itself has an integrated system for monitoring emission levels in real time, in all segments, during all segments of the plant's operation, in all conditions. So from that side, we will also have, I repeat, in real time, what the emission level is, whether it is within the legally defined limits, as foreseen by the technology itself," she pointed out.

The facility will be designed to monitor any deviations in gas quality in real time. In addition, control monitoring, or emission monitoring by a national accredited institution, will be established. There is a risk in accident situations.

"The system itself is equipped with a sufficient amount of equipment for all segments that are its integral part, which is necessary when it comes to regular maintenance, when it comes to the need for temporary shutdown, and in the case of accident situations, there is an aggregate for supplying electricity. The technology from the aspect of energy efficiency that will be applied in this system, implies the use of biogas for the production of electricity and heat, so that it will be partially self-sustainable, in the sense that 50% of the need for electricity will be covered by production in the system itself, and the heat energy will be used to cover the waste incineration system. On the other hand, if an accident occurs, a mechanism is foreseen that will allow untreated water to be discharged into the Morača, that is, which allows, these are three bypass lines that allow water to be purified to the level that, within the framework defined by our legislation, is purified in Morača. When it comes to technology, I would like to emphasize that it includes both chemical and biological purification," she pointed out.

According to estimates, the incinerator will produce around 400 tons of hazardous waste annually. Analyses conducted during the preparation of the project documentation showed that the price per ton is around 280 euros. If this average is taken into account, this would require around 100 thousand euros per year.

The water flowing from the plant into the Morača River will be of A1 quality.