A Novel and Rapid Harvesting Method of Microalgae Using Saw Dust Coated Polypyrrole

In this study a simple and rapid harvesting method using electro conductive polymer coated saw dust has been presented as a new coagulant for separating chlorella vulgaris from a diluted suspension. polypyrrole (ppy) coated saw dust as a novel coagulant was prepared via in-situ polymerization of pyrrole (py) monomer using fecl3 oxidant in aqueous medium in which saw dust particles were suspended. the zeta potential of coagulant and c. vulgaris and x-ray photoelectron spectroscopic (xps) analysis of coagulant were characterized. ppy maintain predominantly positive charge over a wide ph range (2-10) with an isoelectric point 10.4 while, c. vulgaris maintained negative surface charge from ph 5 and onward with isoelectric point 3.8. the microalgae showed the highest separation efficiency at ph 10. the maximal recovery efficiency reached more than 90% for microalgae at a stirring speed of 120 rpm within 7 min. the maximal adsorption capacity of c. vulgaris was 28.8 mg dry biomass/mg-saw dust coated ppy. the concentration factor obtained is higher than 32 which save energy and time associated with microalgal harvesting and allows a reduction in the equipment size necessary for biomass dewatering and improves the feasibility of using these microorganisms in biofuel or wastewater processes.