Excessive plastic waste and river water pollution are both never ending environmental problems faced by every country around the world. In this paper, polymeric membrane was synthesized from plastic waste of high density polyethylene (HDPE) type to treat contaminated river water. The plastic waste was grinded into powder of different particle sizes before synthesizing the membrane by sintering method. The membranes were synthesized both with and without the addition of solvents. The heating temperature during membrane synthesis was also being study for membrane performance in terms of percentage of permeate rejection and permeate flux. HDPE membrane produced from average particle size of 270.7 +/- 178.6 mu m achieved the highest permeate rejection and has highest heating temperature (180 degrees C). Field Emission Scanning Electron Microscopic (FESEM) analysis showed that the sintered membranes exhibit a porous asymmetric structure. Meanwhile, Fourier Transform Infrared Spectroscopy (FTIR) analysis denote the HDPE membranes in grouped as alkanes and aromatics compounds. (C) 2017 Penerbit UTM Press. All rights reserved