Novel MIL101(Fe) impregnated poly(vinylidene fluoride-co-hexafluoropropylene) mixed matrix membranes for dye removal from textile industry wastewater

Abstract In this work, the potential of direct contact membrane distillation (DCMD) technology using novel MIL101(Fe) impregnated poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) mixed matrix membranes has been explored for dye removal from the textile industry wastewater. The influence of MIL101(Fe) impregnation on membrane performance was investigated by various morphological (SEM, AFM) and spectral techniques (XRD, FT-IR) along with transmembrane flux and dye rejection efficiency. Membrane performance over the range of feed temperature and the flow rate has also been explored for its applicability and suitability. The permeate flux grows exponentially with the feed temperature, whereas the dye rejection decreased with increased feed temperature. A decrease in boundary layer thickness at the membrane surface resulted in a linear increase in permeate flux with flow rate. The rejection was negligibly affected by the increase in flow rate. Among the fabricated membranes, M-M(0.5) (20% PVDF-HFP/0.5% MIL101(Fe)) membrane was adjudged the most suitable. Response surface methodology was used to investigate the influence of feed temperature and flow rate on permeate flux and dye rejection to optimize membrane performance. The optimized process parameters obtained were feed temperature: 353 K, flow rate: 40 l h−1. For these optimized input process parameters, the predicted responses were permeate flux: 6.75 l m−2 h−1 and dye rejection: 98.14%. Using the optimized parameters obtained from the RSM study, 24 h long run DCMD experiment was done to study membrane fouling on membranes using SEM and FT-IR analysis. The fabricated membranes showed great potential to treat real textile industry wastewater.