Biofilters are systems that use living organisms, typically microorganisms, to remove contaminants from air or water. They work by allowing polluted air or water to pass through a medium, such as soil or compost, where these organisms break down harmful substances into less harmful ones. This process is often used in wastewater treatment and air purification. These systems are environmentally friendly and can be more sustainable than traditional filtration methods. Biofilters can be designed for various applications, including industrial processes, agricultural runoff, and landfill gas management, making them versatile tools for pollution control.