SINGLE-PHASE MEMBRANE OZONATION OF HAZARDOUS ORGANIC-COMPOUNDS IN AQUEOUS STREAMS

The use of ozone to treat hazardous organic wastes in water is limited by the low solubility of ozone in water. The use of semipermeable non porous silicone capillary membranes to transfer ozone nondispersively into an aqueous phase and ozonate organic species has been studied for the single pollutants phenol, nitrobenzene and acrylonitrile. Prelimi nary experimental results are presented here to demonstrate the effica cy of such a process using silicone capillary membranes. The substanti ally larger a (surface area per unit volume of device) (15.3 cm2/cm3 i n the case of module 2) that this membrane ozonator provides leads to a significantly larger value of mass transfer parameter compared to th ose in conventional equipments. For iodometric consumption of ozone, t he value of k(l)a in presence of reaction was found to be 5.8 x 10(-3) s-1 in module 2 compared to calculated values of 1.058 x 10(-3) s-1 f or a packed column containing Raschig rings 1.3 cm in size and 3.22 x 10(-4) s-1 for a bubble column operating under comparable superficial gas and liquid velocities.