Separation of landfill leachate with polymeric ultrafiltration membranes

The use of ultrafiltration for treatment of landfill leachate was evaluated. A high-strength industrial landfill leachate that has undergone some pretreatment contains residual suspended solids. These solids have molecular diameters greater than 190 Å and diameters between 32 and 55 Å, and foul ultrafiltration membranes. The fouling layer is 99 percent inorganic and does not block the passage of organic carbon across the membrane. It acts simply to create a pressure drop that results in lower flux. This fouling layer can be minimized by increasing shear at the membrane surface (increased stirring rate) and/or lowering the strength of the leachate. Membranes cast from an aromatic polymer exhibit the highest flux when used with leachate.