Jätevedenpuhdistamoissa

Jätevedenpuhdistamo is the Finnish term for a wastewater treatment plant. These facilities are essential for public health and environmental protection, responsible for removing contaminants from domestic and industrial wastewater before it is discharged back into natural water bodies or reused. The process typically involves several stages.

The first stage is preliminary treatment, which removes large debris like rags, grit, and sand. This is usually done using screens and grit chambers. Following this is primary treatment, where wastewater flows slowly through large tanks, allowing heavier solids to settle to the bottom as sludge, and lighter materials like oil and grease to float to the surface.

Secondary treatment is the core of the biological purification process. Here, microorganisms, primarily bacteria, are used to consume and break down dissolved organic matter. This is often achieved through processes like activated sludge or trickling filters, where the wastewater is aerated to provide oxygen for the microbes.

The final stage, tertiary treatment, aims to further refine the water quality. This can involve removing nutrients like nitrogen and phosphorus, which can cause eutrophication in receiving waters. Disinfection, often using chlorine or UV radiation, is also a common part of tertiary treatment to kill any remaining harmful bacteria or viruses. The treated sludge collected throughout the process is then managed, often through dewatering and disposal or further processing.