Filterbäddar

Filterbäddar, also known as biofilters or trickling filters, are a type of biological wastewater treatment system. They are commonly used in municipal and industrial wastewater treatment plants to remove organic pollutants. The fundamental principle involves passing wastewater over a bed of filter media, such as gravel, plastic, or wood chips. This media provides a large surface area for a biofilm to grow.

The biofilm is a complex community of microorganisms, including bacteria, fungi, and protozoa, that are responsible for breaking down the organic matter in the wastewater. As the wastewater flows through the filter media, these microorganisms consume the dissolved and suspended organic compounds, converting them into simpler substances like carbon dioxide, water, and new microbial cells.

Filterbäddar can be broadly categorized into two main types: trickling filters and submerged biofilters. Trickling filters operate with the wastewater trickling down through the media, allowing for good aeration. Submerged biofilters have the media fully submerged in water, often with forced aeration or relying on natural circulation. The efficiency of a filterbädd depends on factors such as the type of media, the hydraulic loading rate, the organic loading rate, and the temperature. They are a robust and effective technology for secondary wastewater treatment.