Utilization of drinking water bottle waste as a sustainable and low-cost membrane material in water purification

The rapid development of membrane technology in various applications requires new membrane materials to achieve good separation performance. Materials in great demand are low in cost, easy to prepare, sustainable, and have good separation performance. In addition, consideration of environmental aspects is also crucial in the selection of membrane materials. On the other hand, plastic bottle waste, which increases every year (381.73 million tons), has the property of forming films or thin layers. Therefore, plastic bottle waste as a low-cost, sustainable, and “green” membrane material has great potential. The membrane from PET plastic bottle waste (PET-B membrane) was prepared using the immersion-precipitation phase inversion technique. Modification of the membrane is done by adding LiCl as an additive. Furthermore, the fabricated membranes were tested for their performance in water purification. The results showed that the PET-B membrane had a porosity of 74.8%. The addition of LiCl can increase the porosity of the PET-B membrane to 81.4%. The addition of LiCl caused an increase in flux to 3 times (65.30 Lm^-2h^-1bar⁻¹ to 171.1 Lm^-2h^-1bar⁻¹) and an increase in rejection from 64.46% to 99.45%.