This paper reports the effects of pH, gas-liquid flow rate ratio, membrane length, and membrane contactor configuration on the oxidation of iodide by ozone. Comparison between membrane contactor and bubbling technology was also conducted and the application of membrane contactor is confirmed to improve the iodide oxidation process. The best configuration for iodide oxidation process is the liquid (acidic iodide solution) flows through the shell side and the gas (ozone) flows through the tube side. In this configuration, the acidic iodide solution passes the membrane pores and contacted with the ozone at the membrane lumens. To get optimum process condition, overall mass transfer coefficient (K-ov) was investigated and statistic examination was conducted for non-looping system. The highest potassium iodide (KI) conversion was achieved at pH of 1, gas-liquid flow rate ratio of 35 and membrane length of 0.5 m with K-ov of 1.88 x 10(-6) m/s. Based on statistic examination, pH did not give a significant effect on the conversion compared to gas-liquid flow rate ratio, membrane length. According to that, this process should be held at pH of 2, gas-liquid flow rate ratio of 35, and membrane length of 0.5 m with K-ov of 1.71 x 10(-6) m/s. (C) 2012 Elsevier B.V. All rights reserved.