Development of Ultrafiltration Membrane from Polyethylene Terephthalate (Pet) Bottle Waste

Polyethylene Terephthalate (PET) bottle is used as beverage packaging, which is very convenient as one time use packaging. However, the huge amount of PET bottle waste has been becoming a serious problem for the environment. The utilization of PET bottle waste is very important to reduce the environmental problem. In this work, PET bottle waste was used a raw material to develop an ultrafiltration (UF) membrane. The membrane was prepared by using a phase inversion technique. The effect of the type of solvent, additive, and non-solvent on the microstructure and ultrafiltration performance of the membrane was studied. Different type of solvent, phenol, m-cresol, and DMSO were used to dissolve PET bottle as the source of membrane polymer. Two different additives, Polyethylene Glycol (PEG) and Polyvinyl Pyrrolidone (PVP) were used. Membrane 3 with the composition of PET, phenol as solvent, and PEG as additive was prepared successfully. The variation of aqueous alcohol solutions as non-solvent resulted in different microstructures of the membranes as shown by the scanning electron microscopy (SEM). The permeation experiment result using pure water as the feed showed that membrane 3 using aqueous butanol as non-solvent (membrane 3-ButOH) exhibited the highest permeate flux compared to that of membrane 3 using aqueous propanol (membrane 3-PrOH) or ethanol as non-solvent (membrane 3-EtOH). The ultrafiltration experiment was carried out using a feed solution of water containing polyethylene glycol (PEG) 20,000. The membrane 3-EtOH showed the lowest permeate flux of 3.24 kg/m h, but the highest rejection of PEG 20,000 of 65.87%. The membrane 3-PrOH had a permeate flux of 11.57 kg/m h and a rejection of 64.73%. Whereas the membrane 3-ButOH showed the highest permeate flux of 27.78 kg/m h, but the lowest rejection 16.93%. This result was obtained due to the different membrane microstructures which were strongly affected by the type of non-solvent.