Reaction pathways and kinetics parameters of sonolytically induced oxidation of dimethyl methyl-phosphonate in air saturated aqueous solutions

The oxidation of dimethyl methylphosphonate (DMMP) was examined under ultrasonic conditions (640 kHz) in oxygen saturated aqueous solutions. Acetic acid, formic acid, methylphosphonic acid, phosphate, and oxalic acid have been identified as the major products produced during the sonolytic irradiation of DMMP. The initial rates of oxidation were determined as a function of initial DMMP concentration. The kinetic behavior of the system is consistent with the Langmuir-Hinshelwood model implying oxidative processes occur at or near the gas-liquid interface during cavitation. Mechanistic implications and conclusions are discussed based on the product distributions and kinetic parameters.