Sonochemical degradation of a polydisperse nonylphenol ethoxylate in aqueous solution

Abstract

The ultrasound (363 kHz) induced decomposition of a commercially available polydisperse nonylphenol ethoxylate surfactant (Teric GN9) has been investigated. The initial rate of decomposition was found to be a function of the monomer concentration of the surfactant below and above the critical micelle concentration. Based on HPLC, TOC, GC, and sonoluminescence quenching measurements, we conclude that the initial pathway for the decomposition of the Teric GN9 occurs via a combination of thermal breakdown and radical attack on surfactant molecules adsorbed at the surface of cavitating bubbles. Nearly 90% mineralization and/ or degradation into volatile products of the surfactant was achieved af..