Filtration is an important and common unit operation in chemical engineering. It is frequently used in combination with other unit operations to effectively treat feed streams. A good case in point is the biofilter, which both filters and biologically digests, offering an integrated solution to contaminant removal and pollutant degradation in a single system. This integration allows for greater process efficiency and effectiveness in many applications.

Filtration is a general process involving different mechanical, physical, or biological processes to remove solids from liquids or gases using a medium through which only the liquid or gas can pass. The liquid or gas that passes through the medium successfully is known as the filtrate. Filtration is a critical process with significant applications in various industrial processes as well as environmental management to ensure efficient separation and purification.