An efficient and simple strategy for fabricating a polypyrrole decorated ceramic-polymeric porous membrane for purification of a variety of oily wastewater streams

Abstract

A ceramic-polymeric membrane was fabricated through in-situ oxidative polymerization of pyrrole (Py) on alumina (Al2O3) ceramic ultrafiltration support. The establishment of polypyrrole (PPy) active layer on the ceramic support led to a new PPy coated ceramic-polymeric membrane. Various salient features such as surface wettability, surface morphology, composition and functional goups of PPy coated ceramic-polymeric membrane were determined by various characterization techniques water contact angle (WCA), scanning electron microscopy (SEM), energy dispersive x-ray (EDX) analysis and attenuated total reflectance fourier transform infrared (ATR-FTIR). The PPy coated ceramic-polymeric membrane showed superhydrophilic nature owing to its under water oil contact angle of ≥160° (superoleophobic). Thanks to stable deposition of PPy active layer on ceramic support, the membrane retained a separation efficiency of >99% for O/W emulsions at varied transmembrane pressures ranging from 0.5 bar to 2 bar with a feed concentration of 125 ppm of oil in water. Moreover, the PPy coated ceramic-polymeric membrane exhibited an ideal behaviour to the applied transmembrane pressure with a linear increase from 380 LMH to 2112 LMH in permeate flux as the pressure increased from 0.5 bar to 2 bar. As the concentration of oil was raised from 50 ppm to 250 ppm, the separation efficeincy separation remained at >99%. From among the different types of oils (Motor oil, Diesel oil and Crude oil) to mimic the oily waste water streams, the permeate flux was found to be highest in case of motor oil with a value reaching to 1690 LMH at 1 bar. The stability test revealed that the PPy coated ceramic-polymeric membrane was able to separate >99% of 125 ppm O/W surfactant stabilized emulsion for a period of 420 min.