Revolutionizing membrane Performance: Repurposing drinking water bottle waste for enhanced chromium removal in wastewater treatment

Wastewater from the electroplating industry contains chromium (VI) ions, which can cause lung cancer, nose cancer, DNA transcription issues, kidney failure, liver damage, and digestive tract disorders. Developing membrane technology that effectively removes chromium ions at a low cost is crucial to addressing this problem. This research utilizes plastic waste from drinking water bottles of polyethylene terephthalate (PET-PW) to create a low-cost and environmentally friendly membrane material to address this problem. Modifications were made by adding zeolite-Y (ZY) filler and cellulose acetate (CA) membrane coating to enhance its performance in removing chromium (VI) ions. The research results showed that adding ZY and CA coating increased the porosity value of the PET-PW membrane from 75 % to 82 % and 83 %, respectively. These modifications changed the surface pores and cross-section of the membrane to become relatively smaller and more sponge-like than the PET-PW membrane. The CA coating on the PET-PW/ZY membrane produces a membrane with two layers, where the top layer has larger finger-like pores than the bottom layer. The performance of the ZY-modified PET-PW membrane increased the rejection of chromium (VI) ions from 4 % to 48 %. The chromium flux produced by the PET-PW/ZY membrane is 120 Lm^-2h^-1bar⁻¹. The CA coating increased the water flux from 50 Lm^-2h^-1bar⁻¹ to 200 Lm^-2h^-1bar⁻¹. This CA coating also increased chromium (VI) ion rejection from 60 % to 70 %. Thus, this study demonstrates a very perspective and cheap way of pollution abuse regarding chromium VI, while utilizing plastic waste to create an environment-friendly solution.