Systems and methods for plasma-based remediation

A system for chemically altering an NOx concentration of an exhaust stream, comprising:

• an exhaust inlet port;
• an exhaust outlet port;
• first and second parallel elongate conduits fluidly coupling the exhaust inlet port to the exhaust outlet port;
• a pulse voltage source;
• a voltage connector disposed between the first and second parallel elongate conduits, said voltage connector electrically coupled to the pulse voltage source, said voltage connector comprising a first tapered, insulating end protruding into an interior of the first elongate conduit and a second tapered, insulating end protruding into an interior of the second elongate conduit;
• a first electrically conductive member extending through the first tapered, insulating end and a second electrically conductive member extending through the second tapered, insulating end;
• and
• a first electrode aligned axially within the first elongate conduit and electrically coupled to the first electrically conductive member and a second electrode aligned axially within the second elongate conduit and electrically coupled to the second electrically conductive member;
• wherein said pulse voltage source is configured to produce a transient plasma within the first and second elongate parallel conduits;
• and
• wherein said transient plasma is adapted to remove a portion of NOx flowing from the exhaust inlet port to the exhaust outlet port.