Performance of polycaprolactone/TiO₂ composite membrane for the effective treatment of dairy effluents

This work is the first, to the best of our knowledge, to use polycaprolactone (PCL)-based membrane for the treatment of dairy wastewater. PCL is a biodegradable polymer with high biocompatibility and good oil resistance. The chlorine tolerance analysis of PCL-based membranes exhibited a good tolerance against chlorine. The PCL/TiO₂ nanocomposite membrane with the addition of polyethylene glycol was prepared and tested for protein separation. The dependency of contact angle with time was analysed for the membrane, and the contact angle value reduced from 74.5 ± 2° to a steady value of 65 ± 2° in 120 s. The proteins were removed using a cross-flow filtration unit at an operating pressure of 0.4 MPa at room temperature with permeate flux of 10 L/m² h and a relative permeate flux of about 0.10. The removal of proteins was measured qualitatively using native polyacrylamide gel electrophoresis (PAGE) and quantitatively using Lowry's test. A percentage rejection of 97.6 was obtained and the native PAGE showed the complete removal of all the major proteins present in the milk sample.