Recovery of Pure Water, Salicylic Acid Crystals, and Paracetamol using PVDF-MWCNT Membranes by Membrane Distillation-crystallization

Abstract

Membrane distillation-crystallization (MDC) is presented as a novel technique in the treatment of waste concentrated water which produces valuable crystals along with pure water. In the present study, multi-walled carbon nanotubes (MWCNT)/polyvinylidene fluoride (PVDF) flat sheet membranes were prepared via the wet phase inversion method and applied in MDC for the treatment of pharmaceutical waste. The pure and modified membrane surface properties are characterized with the help of SEM, FTIR, and contact angle measurement. The present work reported the effect of MWCNT content and feed temperature on the MDCperformance and measured pure water flux and pharmaceutical compounds recovery. The observed maximum permeate flux and crystal recovery for Salicylic acid system was 5.5 kg/m2h and 50%, respectively for PVDF+0.5% CNT membrane and 5 kg/m2h and 48%, respectively for pure PVDF. Also, for paracetamol system it was 3.9 kg/m2h and 41% for PVDF +0.5% CNT membrane and 3.5 kg/ m2h and 38% for pure PVDF. Obtained results show that MDC has good potential in treating pharmaceutical waste.