Ultrasound cleaning method with suspended nanoparticles

A method for reducing level of contaminants from objects carrying contaminants, the method comprising:

• introducing the objects into an ultrasonic (US) bath carrying a liquid medium holding suspended therein water insoluble nanoparticles, wherein said objects are plant parts;
• and
• activating said bath to cause US waves in said liquid medium while the objects are at least partially submerged within said liquid medium;
• wherein said bath is activated at a frequency of at most 150 kHz, said frequency being sufficient to cause movement of the water insoluble nanoparticles within said liquid medium and thereby removal of said contaminants from the objects;
• wherein said nanoparticles comprise at least one of a metal oxide and a silicon oxide at a determined density,
• wherein said objects are plant parts;
• said nanoparticles in the US bath are at a concentration of between 0.0001% w/v to 1.0% w/v;
• and
• said nanoparticles have an average diameter in a range of 30 nm to 80 nm.