ENHANCEMENT OF MEMBRANE DISTILLATION OF PET TRACK-ETCHED MEMBRANES BY HYDROPHOBIZATION WITH DICHLORODIMETHYLSILANE

Abstract

Recent reports from the United Nations show that approximately 1.8 billion people live in countries that experience an absolute shortage of water resources. Due to global population growth and industrialization, it is expected that water consumption will lead to a 40% shortage of fresh water by 2030. Desalination by membrane distillation can help to reduce lack of water by extracting fresh water from polluted sources, including seawater, and wastewater. In this study, new types of membranes have been tested for this purpose. Hydrophobic track-etched membranes (TeMs) based on poly(ethyleneterephtalate) (PET) were prepared using covalent binding of silicon monomer such as dichlorodimethylsilane (DCDMS). Efficiency of hydrophobization was increased by preliminary oxidation by hydrogen peroxide treatment. Pre-oxidation of PET TeMs leads to an increase inwater contact angle (CA) up to 102º.The effect of reagent concentration, reaction time were studied by scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), gravimetrically, water- and gas-flow rate, contact angle measurements. The performance of the modified membranes was evaluated using direct contact membrane distillation (DCMD) process. The results show maximum water flux of 17 kg/m2·h during 6h of saline solution operation at 15 g/l with efficiency up to 98 %.

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