Apparatus and method for urea electrolysis with controlled alkalinity

Abstract

Apparatus and method for electrolysis of urea is capable of removing urea from waste-water generated by human urine or agricultural run-off while simultaneously producing cleaner water and hydrogen gas. The apparatus and method employ at least one water reduction electrode located close to at least one urea oxidation electrode. The water reduction electrode operates to generate a locally high pH such that the urea oxidation electrode operates in a locally high pH envelope where it can perform its reaction efficiently to break down the urea with little or no impact on the pH of the bulk solution.

What is claimed is: 
     
         1 . A method of removing urea from an aqueous solution, the method comprising:
 bringing the aqueous solution into contact with at least one water reduction electrode;   generating hydroxide anions at the water reduction electrode to produce a concentration of hydroxide anions in a volume of the aqueous solution;   arranging for the volume of the aqueous solution having the concentration of hydroxide anions to come in contact with at least a portion of a urea oxidation electrode;   allowing a reaction at the urea oxidation electrode to take place in order to electrolytically break down the urea to produce at least CO 2  and N 2  gasses,   wherein the concentration of hydroxide anions is in the aqueous solution in the volume contacting at least the portion of the urea oxidation electrode such that urea removal from the aqueous solution proceeds by electrolytic breakdown of urea.   
     
     
         2 . The method of  claim 1 , further comprising:
 providing a counter electrode in contact with the aqueous solution; and   using the counter electrode to maintain a charge balance with currents passing at the water reduction electrode and the urea oxidation electrode.