A biofilm reactor is a type of wastewater treatment system that utilizes biofilms to remove contaminants from water. In this system, microorganisms attach to surfaces, forming a thin layer known as a biofilm. As water flows through the reactor, these microorganisms break down organic matter and pollutants, effectively cleaning the water. Biofilm reactors can be designed in various configurations, such as moving bed biofilm reactors (MBBR) or fixed film reactors. They are often used in municipal and industrial applications due to their efficiency and ability to handle varying loads of contaminants. This technology helps improve water quality and supports environmental sustainability.