Reningsanlägg

A reningsanlägg, or wastewater treatment plant, is a facility designed to remove pollutants from wastewater before it is discharged into the environment. This process is crucial for protecting public health and aquatic ecosystems. Wastewater, which includes domestic sewage, industrial effluent, and stormwater runoff, contains a variety of contaminants such as organic matter, nutrients like nitrogen and phosphorus, heavy metals, pathogens, and suspended solids.

The treatment process typically involves several stages. Primary treatment focuses on removing solid materials through screening and sedimentation. Wastewater passes through screens to catch larger debris, followed by settling tanks where heavier solids sink to the bottom as sludge. Secondary treatment uses biological processes to break down dissolved organic matter and nutrients. Microorganisms, often in aerated tanks, consume these pollutants. Tertiary treatment, or advanced treatment, is employed to further purify the water, removing specific contaminants like nutrients, pathogens, or micropollutants. This can involve filtration, disinfection (e.g., UV radiation or chlorination), or advanced oxidation processes. The treated effluent is then discharged, and the removed sludge is often further treated and disposed of or reused.