Ultrafiltration (UF), a membrane separation technique, excels at removing particulate materials from solutions. Widely employed in industrial and research settings, this separation process proves invaluable for purifying and concentrating macromolecular solutions, particularly those in the range of 103–106 Da, such as protein solutions. Operating on the principles of size exclusion or particle capture akin to microfiltration, ultrafiltration membranes are characterized by their Molecular Weight Cut-Off (MWCO). The application of cross-flow or dead-end mode varies according to specific requirements.

Ultrafiltration membranes selectively allow the passage of small molecules, including leachate molecules, inorganic salts, and micromolecular organics. However, they effectively restrict the passage of larger macromolecules such as SS, colloids, proteins, and bacteria. UF emerges as a preferred method for pretreating leachate with lower organic concentrations before embarking on nanofiltration (NF). This sequential approach optimizes the overall purification process, ensuring that NF can target and effectively remove remaining contaminants, thereby enhancing the efficiency of the treatment system. In diverse process and wastewater scenarios, the imperative is not solely to diminish dissolved ions but to skillfully reduce colloidal inorganic or organic molecules. Ultrafiltration (UF) membrane configurations and system designs closely mirror those utilized in the single-stage Reverse Osmosis (RO) process. Notably, the larger molecules that UF effectively eliminates exert minimal osmotic pressure, resulting in operational pressures that consistently remain considerably lower than those witnessed in RO systems. Among its various applications, UF excels in curtailing oil and grease, while also facilitating the recovery of valuable impurities within process waste streams.