Aeration Element Descaling / Diffuser Descaling:

Diffuser descaling is a process in which contaminants, particularly lime deposits, are removed from the aeration elements in a wastewater treatment plant. These diffusers are responsible for introducing oxygen into the wastewater, a critical step in the treatment process, as it promotes the growth of microorganisms that break down pollutants.

Over time, deposits such as lime can accumulate on the diffusers. This can reduce their efficiency and increase energy consumption for compressed air generation. Diffuser descaling, often performed using an acid dosing system, applies acid to the diffusers to remove these deposits. The result is improved diffuser efficiency, reduced energy consumption, and extended lifespan of the aeration elements and, consequently, the entire plant.

Why Aeration?
The activated sludge process is used in the majority of municipal wastewater treatment plants. Here, wastewater and activated sludge are aerated in so-called aeration tanks. Aerobic bacteria and microorganisms consume oxygen and convert carbon compounds primarily into carbon dioxide and biomass. Nitrogen from organic compounds is initially converted into ammonia and then oxidized to nitrate. The activated sludge process operates continuously, with wastewater being fed in and aerated water with activated sludge being discharged.

Municipal and industrial wastewater treatment plants use blowers to treat wastewater. In the biological treatment stage, the tanks are aerated, where aerobic degradation processes take place. Additionally, diffusers can mix the water, replacing more energy-intensive agitators. In rural areas, wastewater ponds are also used for preliminary wastewater treatment. Aerating such ponds can reduce their space requirements and improve treatment performance. Approximately 70% of the energy consumed by a wastewater treatment plant is attributed to aeration systems. Therefore, efficient compressed air supply is critical to reducing operating costs. This is not only relevant for municipal treatment plants but also for dairies, breweries, and beverage bottlers, which operate their own treatment plants to reduce the load on municipal facilities.

The constant and reliable air supply to the aeration tanks is essential, as the bacteria responsible for the degradation processes can only survive for a short time without oxygen. The blowers must therefore be low-maintenance and reliable. Depending on the specific treatment plant, the inflow of wastewater may vary, which also affects the compressed air demand. When investing in new systems, maintenance costs and, in particular, energy consumption should be considered. Regular maintenance with an acid dosing system, such as the DOSY-S acid dosing system, can significantly reduce energy consumption and improve the CO2 balance.

Summary:
A significant cost factor in wastewater treatment plants is compressed air generation, which is required to supply the aeration system. Energy costs increase when aeration elements or diffusers become fouled, for example, by lime or other deposits. The higher energy demand is accompanied by increased resistance in the diffusers and reduced lifespan of system components. A solution to this problem is the regular use of acid. By using a mobile acid dosing system, such as those provided by ETL, operators can introduce acid directly into the aeration line. This process enables the descaling and cleaning of diffusers, resulting in improved bubble patterns, reduced pressure in the aeration system, and energy savings of up to 10%.