Trickling filter systems, their function and their properties

Tricklers work on their principle like filters. However, the wastewater treatment also take over bacterial cultures here.

Functional principle of the trickling filter

Tricklers contain a filler material through which the wastewater is passed. Fillers may be, for example, plastic or lava paints.

On the plastic bacteria are collected from the wastewater, which proliferate over time and form a so-called bacterial lawn on the grained filler. With each waste water entry into the trickling filter, the bacteria receive new nutrients and multiply again.

To activate the bacteria, oxygen is supplied to the trickling filter from below. The ventilation flow runs exactly opposite to the inlet direction of the water. This ensures maximum oxygen enrichment.

After the water has run through the trickling filter, a further secondary clarification in a secondary clarifier is required. In this secondary clarification, the bacteria washed out are also separated again.

Advantages and disadvantages of the trickling filter method

Unlike plants with activated sludge process, the amount of sewage sludge in plants according to the trickling filter principle is comparatively low.

Due to their simple design, trickling filters are also more robust and require less maintenance. In addition, there is no risk of bulking. The mud index is also low.

The problem is that no denitrification - so no removal of nitrogen - can take place by trickling filter. This would require additional clarification steps, which are generally structurally not worthwhile.

Distribution of trickling filter systems

Trickling bodies are very rare - even in the municipal area, where they would mean a major construction effort. In small wastewater treatment plants, they are only worthwhile if no denitrification of the wastewater has to be carried out.

Tips & Tricks

The universally applicable process for wastewater treatment is the activated sludge or SBR technology. Here, cleaning services are achieved which correspond to the scope and the process quality of the services of municipal sewage treatment plants.

Video Board: Trickling filter system