Trickling filters
SESSIL® and BIO-NET® support trickling filter equipment. They can be used at
industrial and municipal waste water treatment sites and guarantee low sludge
disposal costs through a lower production of excess sludge. The biomass is not
flushed out by hydraulic impacts, as it is fixed to the support bracket. The trickling
filter process has the particular advantage that it has low control regulation costs,
thus reducing costs for the installation and regular maintenance of the measuring,
control and feedback control systems to a minimum. Therefore, for example, for
measuring the operating weight of SESSIL® trickling filters, simple and robust
mechanical systems can be used instead of electronic measuring systems. The
process also has the advantage that the requirements for the technical training
of the operator can be lowered.
The use of compressed aeration systems in activated sludge plants and SBR plants results in very high annual energy costs, which add up over the life-span of the plant and quickly overtake the construction costs. These costs do not apply to trickling filters, as due to the flue effect within the trickling filter, ventilation takes place naturally. In an ideal scenario, the waste water would be fed to the trickling filter in freefall, which would additionally dispense with the energy costs for operating the feeder pump. With artificial ventilation no longer being a necessity, this results further in a very high plant availability if there are irregularities in the supply of energy, as micro-organisms in waste water treatment survive much longer without sustenance than without oxygen.
- SESSIL® and BIO-NET® can be used as support material
- Static design in accordance with DIN regulations
- Existing trickling filters can be rehabilitated at low cost
Submerged fixed bed systems
The submerged fixed bed procedure is now being used more frequently for industrial and communal sewage treatment.
Like the trickling filter procedure, it has the advantage of producing smaller amounts of excess sludge and is also extremely compact in design since the active biomass is fixed to a support material. This means that the procedure has clear benefits in comparison with the activation/SBR procedure. When using a submerged fixed bed in particular, the elimination of sewage substances that are hard to degrade is made as easy as possible thanks to the tailored biomass that is attached to the support material.
The main challenge when working with submerged fixed bed systems is preventing the fixed bed material from becoming blocked up and thus avoiding the consequential loss of active surface. Blockages can occur for the following reasons:
- Due to the selection of a specific surface that is too large in relation to the available volumetric load of the system
- Due to poor discharge from the support material due to the structure not being vertical or because the permeability is not completely three-dimensional
This is where SESSIL® and BIO-NET® come into their own, since both materials ensure optimum sludge discharge.
In particular, SESSIL® - with its structure of combined film strips - provides a level of protection against blockage that is unique within the field of fixed bed materials.
- An aeration device installed beneath the support material supplies oxygen to the biomass
- Fixed bed units can be optimally modified in line with the tank geometry
- Cascade design with individual or multiple tanks in which the support material is permanently installed
- Short assembly times thanks to prefabricated elements
- Compact, space-saving design
BIO-NET® system used as a cage-type fixed bed unit with integrated aeration. The unit can be hoisted out of the tank using a crane.
The fixed bed unit consists of a substructure, buoyancy restrainer, and the support material. The aeration device is located beneath the fixed bed unit.