The transport of mercury ions (Hg2+) through hollow fiber supported liquid membrane was examined using the extractant Calix[4]arene nitrile. Optimum condition was achieved using 4.5 pH of feed solution, 0.004 M of Calix[4]arene nitrile as extractant, de-ionized water as stripping solution and an operating temperature of 313 K. Percentages of extraction and stripping of mercury(II) ions obtained reached 99.5% and 97.5%, respectively. The stability of the liquid membrane was investigated and showed stable performance over 24 h. After treatment, mercury(II) ions from petroleum produced water in feed solution was found to be below the legislation limit of 5 ppb. (C) 2015 Elsevier B.V. All rights reserved.