Abstract: An advanced oxidation procedure for treating solution waste water, comprising: applying an ultrasound-Fenton reaction, wherein said ultrasound-Fenton reaction includes: providing oxidants and at least one catalyst selected from bivalent metal ions which include Ti, Fe, Mg, Mo, and Cu; subjecting the treated solution and said oxidants and catalyst to ultrasound cavitation generated by a generator device; forcing a flow of treated solution through said ultrasound device adapted to generate ultrasound waves for forming cavitation in said treated solution, said flow of treated solution passing through at least one flow-through tubular reactor chamber of the ultrasound device, and wherein said cavitation is effected by longitudinally linear distributed string of ultrasound transducers fixedly disposed and attached along a length of said at least one tubular reactor chamber, and wherein said cavitation is effected along a width dimension of said reactor chamber.