Method and apparatus for producing hydroxyl radicals

A method of producing hydroxyl radicals in a fluid in a fluid chamber in an electrochemical cell comprising at least one cathode and at least one anode, the method comprising:

• causing the electrochemical cell to produce hydrogen peroxide in the fluid, wherein the electrochemical cell comprises a cathode assembly comprising the at least one cathode, the cathode assembly further comprising a breathable support layer made of at least one material impermeable to the fluid that resists fluid flow across the support layer and wherein the at least one cathode is on the support layer;
• diffusing a gas separate from the fluid through the support layer, the gas comprising oxygen;
• and
• causing at least one photolyzing radiation source to emit photolyzing radiation into the fluid chamber in the electrochemical cell such that the photolyzing radiation reacts with the hydrogen peroxide to produce the hydroxyl radicals in the fluid.