Filtration techniques are methods used to separate solids from liquids or gases by using a barrier that allows only certain particles to pass through. Common examples include using a coffee filter to separate coffee grounds from liquid or employing a membrane filter in water purification systems. These techniques are essential in various industries, including pharmaceuticals, food processing, and environmental management. Different filtration methods can be categorized based on their mechanisms, such as mechanical filtration, which physically blocks particles, or chemical filtration, which involves reactions to remove contaminants. Each technique is chosen based on the specific requirements of the process, such as the size of particles to be filtered and the desired purity of the final product.