Experimental and model study on the mixing effect of injection method in UV/H2O2 process

Heekyong Oh, Pyonghwa Jang, Jinseok Hyung, Jayong Koo, Sung Kyu Maeng

Research output: Contribution to journalArticlepeer-review


The appropriate injection of H2O2 is essential to produce hydroxyl radicals (OH·) by mixing H2O2 quickly and exposing the resulting H2O2 solution to UV irradiation. This study focused on evaluating mixing device of H2O2 as a design factor of UV/H2O2 AOP pilot plant using a surface water. The experimental investigation involved both experimental and model-based analyses to evaluate the mixing effect of different devices available for the H2O2 injection of a tubular hollow pipe, elliptical type of inline mixer, and nozzle-type injection mixer. Computational fluid dynamics analysis was employed to model and simulate the mixing devices. The results showed that the elliptical type of inline mixer showed the highest uniformity of 95%, followed by the nozzle mixer with 83%, and the hollow pipe with only 18%, after passing through each mixing device. These results indicated that the elliptical type of inline mixer was the most effective in mixing H2O2 in a bulk. Regarding the pressure drops between the inlet and outlet of pipe, the elliptical-type inline mixer exhibited the highest pressure drop of 15.8 kPa, which was unfavorable for operation. On the other hand, the nozzle mixer and hollow pipe showed similar pressure drops of 0.4 kPa and 0.3 kPa, respectively. Experimental study showed that the elliptical type of inline and nozzle-type injection mixers worked well for low concentration (less than 5mg/L) of H2O2 injection within 10% of the input value, indicating that both mixers were appropriate for required H2O2 concentration and mixing intensity of UV/ H2O2 AOP process. Additionally, the elliptical-type inline mixer proved to be more stable than the nozzle-type injection mixer when dealing with highly concentrated pollutants entering the UV/H2O2 AOP process. It is recommended to use a suitable mixing device to meet the desired range of H2O2 concentration in AOP process.

Original languageEnglish
Pages (from-to)129-140
Number of pages12
JournalMembrane Water Treatment
Issue number3
StatePublished - 2023


  • AOP
  • CFD UV/ HO
  • inline mixer
  • mixing
  • nozzle mixer
  • uniformity


Dive into the research topics of 'Experimental and model study on the mixing effect of injection method in UV/H2O2 process'. Together they form a unique fingerprint.

Cite this