Abwasserkläranlagen

Abwasserkläranlagen, also known as wastewater treatment plants, are facilities designed to remove pollutants from sewage and other wastewater. The primary goal of these plants is to protect public health and the environment by treating wastewater before it is discharged back into rivers, lakes, or oceans. The treatment process typically involves several stages.

The first stage is preliminary treatment, where large solid objects like rags, grit, and sand are removed. This is usually done using screens and grit chambers. Following this is primary treatment, where wastewater flows through large settling tanks. Here, suspended solids settle to the bottom as sludge, while lighter materials like oil and grease float to the surface and are skimmed off.

The next stage is secondary treatment, which is primarily biological. Microorganisms, such as bacteria, are used to break down dissolved and suspended organic matter. This is often achieved in aeration tanks, where air is pumped into the wastewater to provide oxygen for the microbes, or in trickling filters. After the biological stage, the wastewater moves to secondary settling tanks to allow the microorganisms to settle out as sludge.

Finally, tertiary treatment, also known as advanced treatment, may be employed to remove specific pollutants not addressed in earlier stages. This can include disinfection processes, such as chlorination or UV irradiation, to kill remaining pathogens, or nutrient removal to prevent eutrophication of receiving waters. The treated effluent is then discharged, and the collected sludge undergoes further processing, such as dewatering and digestion, before disposal or beneficial reuse.