Mechanical Wastewater Treatment for High Operational Reliability

When it comes to wastewater treatment, mechanical processes play a crucial role in removing water-insoluble substances or colloids. These processes involve sedimentation, filtration, and separation techniques, which effectively eliminate solid pollutants from the wastewater.

Mechanical cleaning is the first step in many industrial wastewater plants. This not only ensures operational safety but also reduces the need for unnecessary maintenance and associated costs in subsequent treatment stages.

Additionally, mechanical processes can be utilized for sludge dewatering purposes, particularly in filter presses.

Overall, mechanical wastewater treatment can remove approximately 20% — 30% of the total pollutants from untreated wastewater. The remaining dissolved substances can then undergo further purification through biological or chemical-physical treatment methods.

Mechanical Processes for Wastewater Treatment

Coarse-and-Fine Materials Separation Utilizing Screens and Strainer

Screens and strainers play a crucial role in removing solid contaminants from wastewater. These mechanical processes effectively separate pollutants like diapers, hair, wet wipes, and other solid substances from the wastewater stream. In the treatment of industrial wastewaters, strainers are used to separate textile fibers, paper labels, plastic residues, potato peels, and other production waste.

Depending on the application area, either coarse or fine screens are used to clean the wastewater. These screens feature different sizes of parallel rods, grits, screens, perforations, and meshes. Coarse screens (>20 mm) can separate solid substances as large as human waste, while micro screens (<0.05 mm) can filter tiny particles like sand and sludge.

Maintaining sanitary wastewater treatment systems is crucial. Wet wipes and non-woven materials contain extremely tear-resistant textile fibers that can cause blockages and damage to pumps and mixers. At DAS Environmental Expert, we work closely with our clients to choose the right drum screens and self-cleaning screens that prevent damage to their treatment technology, ultimately reducing maintenance costs.

Schlammfilter in Kläranlage

Mechanical Separation of Solid Substances through Filtration

Filtration is another mechanical process used to separate solid substances from fluids. Paper, textiles, metal, sand filters, cloth filters, and drum screens are commonly utilized filter media. These filtration systems effectively remove organic and inorganic suspended solids, sands, and dust from wastewater. In the case of sludge drainage in filter presses, filtration systems are particularly essential.

Membrane filtration is a specific mechanical separation process where a membrane serves as the filter medium. This method is utilized for the separation of very fine particles.

Wastewater Treatment through Membrane Technology

Membrane filtration plays a vital role in separating dissolved and undissolved substances from wastewater under pressure. The membrane, with its specific pore size, retains particles and molecules of a certain size. Membrane technology is used for water purification, wastewater treatment, process water recycling, and the recovery of valuable substances.


Employed to separate particles, bacteria, yeasts, for cold sterilization, and for the separation of oil-water emulsions.



An important method for treating wastewater and potable water. It separates particles, microorganisms, proteins, and turbidities. Used in the Membrane Activation Reactor (MBR) and to clean water in swimming pools.



Retains viruses, heavy metal ions, large molecules, and fine particles. Used for water softening and potable water treatment.


Reverse Osmosis

Concentrates landfill wastewaters, treats potable water in rural areas, desalinates seawater, and decalcifies boiler water in power plants. This method concentrates dissolved substances in fluids by applying pressure through a semi-permeable membrane, reversing the osmosis process. Also used to produce ultrapure water.


Dr.-Ing. Anita Haupt

Your contact person on the subject of wastewater treatment processes

Dr.-Ing. Anita Haupt

Abteilungsleiterin Verfahrenstechnik Wasserbehandlung