A process for removing compounds from an aqueous effluent, the process comprising: introducing the aqueous effluent through at least one inlet port of an elongate housing of a treatment chamber, the housing comprising longitudinally opposite ends and an interior space, the housing further being generally closed at at least one longitudinal end; ultrasonically energizing and electrically charging an outer surface of a first longitudinally elongate ultrasonic horn of a first longitudinally elongate ultrasonic waveguide assembly located within the housing at a first predetermined ultrasonic frequency and an electrode potential and ultrasonically energizing and electrically charging an outer surface of a second longitudinally elongate ultrasonic horn of a second longitudinally elongate ultrasonic waveguide assembly located within the housing at a second predetermined ultrasonic frequency and the electrode potential to remove compounds from the aqueous effluent, wherein the first waveguide assembly and the second waveguide assembly are oriented in parallel within the housing, and wherein at least one of the first ultrasonic horn and the second ultrasonic horn further comprises a plurality of discrete agitating members in contact with and extending transversely outward from the outer surface of the horn intermediate the inlet port and the outlet port of the housing in longitudinally spaced relationship with each other, the agitating members and the ultrasonic horn being constructed and arranged for dynamic motion of the agitating members relative to the ultrasonic horn upon ultrasonic vibration of the ultrasonic horn at the predetermined frequency and to operate in an ultrasonic cavitation mode of the agitating members corresponding to the predetermined frequency and the aqueous effluent being treated in the chamber; and exhausting the cleaned aqueous effluent from at least one outlet port of the housing. introducing the aqueous effluent through at least one inlet port of an elongate housing of a treatment chamber, the housing comprising longitudinally opposite ends and an interior space, the housing further being generally closed at at least one longitudinal end; ultrasonically energizing and electrically charging an outer surface of a first longitudinally elongate ultrasonic horn of a first longitudinally elongate ultrasonic waveguide assembly located within the housing at a first predetermined ultrasonic frequency and an electrode potential and ultrasonically energizing and electrically charging an outer surface of a second longitudinally elongate ultrasonic horn of a second longitudinally elongate ultrasonic waveguide assembly located within the housing at a second predetermined ultrasonic frequency and the electrode potential to remove compounds from the aqueous effluent, wherein the first waveguide assembly and the second waveguide assembly are oriented in parallel within the housing, and wherein at least one of the first ultrasonic horn and the second ultrasonic horn further comprises a plurality of discrete agitating members in contact with and extending transversely outward from the outer surface of the horn intermediate the inlet port and the outlet port of the housing in longitudinally spaced relationship with each other, the agitating members and the ultrasonic horn being constructed and arranged for dynamic motion of the agitating members relative to the ultrasonic horn upon ultrasonic vibration of the ultrasonic horn at the predetermined frequency and to operate in an ultrasonic cavitation mode of the agitating members corresponding to the predetermined frequency and the aqueous effluent being treated in the chamber; and exhausting the cleaned aqueous effluent from at least one outlet port of the housing.