a method of processing landfill leachate by use of a membrane separation process is disclosed . specifically , the following steps are taken to process landfill leachate : collecting landfill leachate in a receptacle suitable to hold said landfill leachate ; treating said landfill leachate with one or more water soluble polymers , wherein said water soluble polymers are selected from the group consisting of : amphoteric polymers ; cationic polymers ; zwitterionic polymers ; and a combination thereof ; optionally mixing said water soluble polymers with said landfill leachate ; passing said treated landfill leachate through a membrane , wherein said membrane is an ultrafiltration membrane or a microfiltration membrane ; and optionally back - flushing said membrane to remove solids from the membrane surface .