Abstract: Most nitrogen recovery techniques recover acidic ammonium fertilizers, and few enable alkaline ammonia recovery. Many embodiments provide multi-chamber electrochemical stripping reactors to recover alkaline ammonia and acidic ammonium from wastewater. The reactor combines electrodialysis and membrane stripping. The acidic and alkaline product portfolio for wastewater-derived ammonia expand implementation opportunities for nitrogen recovery.

Abstract: An apparatus and method for extracting nitrogen including compounds from wastewater is disclosed herein. The methods and apparatus use molecularly designed selective electrocatalysts, electrolytes, and separation reactors to enable automated, distributed ammonia manufacturing with minimal environmental impacts. In some embodiments, a method of nitrogen reduction of wastewater is provided. The method includes: providing an apparatus including: a first chamber comprising a salt solution; a second chamber comprising a wastewater source; a third chamber comprising a salt solution and a third electrode, wherein the second chamber is positioned between the first chamber and the third chamber; an anion exchange membrane positioned between the first chamber and the second chamber; and a cation exchange membrane positioned between the second chamber and the third chamber; applying a potential bias between any two of the first chamber, the second chamber, and the third chamber.

Abstract: A sensor for gas species in water includes two membranes separating first, second and third chambers. The first and second chambers are separated by an ion exchange membrane, and the second and third chambers are separated by a gas permeable membrane. Water electrolysis in the first and second chambers provides analyte-ions corresponding to an analyte being detected that pass through the ion exchange membrane from the first chamber to the second chamber. Within the second chamber, these analyte-ions generate analyte via the electrolysis. Analyte in the second chamber passes through the gas permeable membrane to arrive at the third chamber. Within the third chamber, the analyte-ion is generated chemically from the analyte. Electrical detection of the analyte-ion in the third chamber provides sensing of the analyte present in the first chamber.