yläraatorilaitokset

Yläraatorilaitokset, which translates to "upper sewage treatment plants" or "primary wastewater treatment facilities" in English, refers to the initial stage of a multi-stage wastewater treatment process. These facilities are designed to remove solid materials and suspended solids from raw sewage before it undergoes further treatment. The primary goal is to reduce the volume and organic load of the wastewater, making subsequent treatment stages more efficient and less costly.

The process typically begins with screening, where large debris such as rags, grit, and other coarse materials are removed using screens or grates. Following screening, the wastewater flows into sedimentation tanks, also known as primary clarifiers. In these large tanks, the flow of water is slowed down significantly, allowing heavier solids to settle to the bottom as sludge, and lighter materials like grease and oil to float to the surface. The settled sludge is then collected and removed for further processing, which may include dewatering and disposal. The partially clarified effluent, still containing dissolved organic matter and other contaminants, then proceeds to secondary treatment. Yläraatorilaitokset are crucial for removing a significant portion of the pollutants and preparing the wastewater for more advanced purification steps.