Biomass assisted microfiltration of chromium(VI) using Baker's yeast by ceramic membrane prepared from low cost raw materials

This work deals with the preparation of ceramic microfiltration membrane from inexpensive raw materials such as kaolin, quartz, calcium carbonate by uniaxial dry compaction method. The prepared green membrane was initially dried at 100 °C for 24 h, 200 °C for 24 h and finally sintered at 900 °C for 6 h. The properties of the membrane such as porosity, flexural strength, chemical stability and hydraulic permeability were investigated. The fabricated membrane possessed an average pore diameter of 1.32 μm, porosity of 30% and flexural strength of 34 MPa. Furthermore, the chemical stability of the membrane was found to be excellent. Eventually, the separation performance of the membrane in terms of flux and removal of chromium(VI) ion using baker's yeast biomass as a function of applied pressure, pH, metal ion concentration and biomass dosage was also studied. The removal of Cr(VI) was found to be strongly dependent on the initial pH of the solution. At lower pH, the metal solution shows higher removal due to higher binding of the metal ion with biomass. It was also observed that the removal of Cr(VI) ion increases with increasing the biomass concentration and decreases with increasing the metal ion concentration. The removal of Cr(VI) was found to be independent of the applied pressure. The maximum removal of Cr(VI) was found to be 94% with the permeate flux of 2.07 × 10^-5 (m³/m² s) for a metal solution concentration of 100 mg/L.