Ultrafiltration is a pressure-driven separation process wherein small molecules permeate through, while large ones are retained by, a semi-permeable membrane. When a surfactant above the critical micelle concentration is added, small molecules are entrapped in micelles and retained by the membrane. This process is called micellar-enhanced ultrafiltration. Alternatively, a polyelectrolyte is added which binds the ionic solute and prevents its permeation across membrane; this is called polyelectrolyte-enhanced ultrafiltration. Using prepared cellulose acetate membranes, volatile organic compounds from mango puree and processing effluent can be recovered. On the other hand, by using polyamide membranes, growth hormones and sugar have been separated from coconut water. The cellulose acetate membranes were also used to separate dissolved metals ions such as NO3-, P2+, Cd2+, Zn2+, and Hg2+ from wastewater.