A sono-molecular-conversion device and method for effecting nitrification of ammonia in water, the method including feeding the water containing ammonia through a sono-molecular conversion device including a plurality of ultrasound transducers and applying ultrasonic energy to the water containing ammonia by the sono-molecular conversion device to ultrasonically collapse microsized bubbles with transient cavitation in the water containing ammonia to effect nitrification of ammonia therein by sono-molecular-conversion.
