Ozonation of soluble organics in aqueous solutions using microbubbles

This work investigates ozonation of a mixture of benzene, toluene, ethylben zene, and xylenes (BTEX) dissolved in aqueous solutions having salt concent rations ranging from 0 to 2 M. The effect of microbubbles on the ozonation rate is examined. Microbubbles are formed either by an electrostatic sprayi ng method or by a small-pore bubble diffuser. Although electrostatic sprayi ng is effective for BTEX removal in low-conductivity solutions, results ind icate it is not suitable for microbubble formation in high-ionic-strength s olutions due to high electric current. In contrast, the bubble-diffuser met hod proved to be very effective in producing small bubbles in high-ionic-st rength solutions. The production of small bubbles makes it possible to miti gate the mass transfer limitation, which has been shown to be the primary r estriction in ozonation systems. When a bubble diffuser is employed, the re moval rate of BTEX from simulated seawater is approximately twice that obta ined with a simple capillary tube.