Investigation of radical reactions for efficiency improvement in ozone hydrogen peroxide treatment

It was verified by laboratory-scale experiments that the two-port ozone injection method was more advantageous for reaction efficiency in the ozone-hydrogen peroxide treatment than the conventional one-port ozone injection method under the condition of same ozone dose. The reason for this effectiveness was also investigated in detail by computer simulations in the wide range of the rate constant of OH radical reacting with TOC (k(TOC)). The laboratory-scale experiments revealed that the amount of TOC decomposed (Delta TOC) increased by up to 41 % by the two-port injection method, indicating a 27% improvement in DeltaO(3)/Delta TOC. A detailed investigation of these experimental results by computer simulations showed that by injecting ozone in two ports the amount of ozone consumed for the OH radical formation was increased more remarkably than that of ozone consumed for the radical chain reactions, and that the amount of OH radical reacting with TOC was increased more strikingly than that with ozone. Furthermore, it was found that the smaller the k(TOC) value within 10(5)-10(9) M(-1)s(-1) was, the more advantageous for the reaction efficiency the two-port injection method was.