Separation of Bacteria Kocuria rhizophila from Fermentation Broth by Cross-Flow Microfiltration Using Inexpensive Tubular Ceramic Membrane

In this work, a ceramic membrane with tubular configuration was made via the extrusion method using naturally available clay materials such as ball clay, white clay, quartz and calcium carbonate and sintered at 1000 °C. Along with thermogravimetric (TGA and DTA), X-ray powder diffraction (XRD) and scanning electron microscopic (SEM) analysis, the tubular membrane was characterized for porosity, water permeability, average pore size and chemical tolerance. The porosity, water permeability and average pore size were calculated to be 25%, 5.40 × 10 –4 L/m 2 hPa and 194 nm, respectively. The membrane showed better chemical tolerance as it is more stable in acid, alkali and chlorine solutions. The membrane was utilized in separating the bacteria Kocuria rhizophila from its culture broth which was used for the synthesis of silver nanoparticles. The influence of operating parameters such as cross-flow rate and pressure on permeate flux and rejection was investigated. It was observed that the pressure shows more effect on permeate flux and rejection than the cross-flow rate. The maximum bacteria rejection of 99.6% with average permeate flux of 3.6 L/m 2 h was observed at a pressure and cross-flow rate of 69 kPa and 100 L/h, respectively.