Patent ID: 7517456

Claim:
A method for treating landfill leachate comprising the steps of: (a) coagulatively settling the leachate to produce a supernatant liquid; (b) followed by, filtering said supernatant liquid through a filtration device to produce a first filtered liquid; (c) followed by filtering said first filtered liquid in a reverse osmosis apparatus to produce a second filtered liquid; and (d) followed by, treating said second filtered liquid with a chlorine-based oxidant to produce a purified liquid; Wherein said filtration device is a 3-stage filtration device comprising: a first stage cartridge filter having a wire wound cartridge with pore size of about 10-30 um; a second stage cartridge filter having a cartridge selected from a wire wound cartridge, and a melt-blown spun cartridge, said cartridge having pore size of 5-15 um; and a third stage cartridge filter having a melt spun cartridge with pore size of about 3-10 um; wherein a scale inhibitor is introduced between said second stage filter and said third stage filter; and wherein during coagulatively settling the leachate the pH of the leachate is adjusted between about 10.5 to 11.