Patent ID: 7632406

Claim:
An apparatus for treatment of water to remove nitrate from the water wherein the water includes nitrate ions and wherein the nitrate ions have a thickness and a charge, comprising: a water source containing nitrate ions a cathode, an anode, a voltage source connected to said cathode and to said anode, and a microengineered porous membrane stack, said microengineered porous membrane stack including an anion permeable membrane having a surface, wherein the water is directed along said surface, a series of nanopores extending through said anion permeable membrane from said surface, said nanopores having a pore size, wherein said pore size is smaller than double the thickness of the nitrate ions and wherein said pore size is such that when the water contacts said surface of said anion permeable membrane, said nanopores will be in a condition of double layer overlap and allow passage only of nitrate ions with a charge opposite to said electrical charge across said anion permeable membrane and wherein the nitrate ions are drawn toward said cathode for removal.