Diatomite coated plate and frame filter press as novel harvest method of microalgae biomass: Design and pilot-scale...

Filtration-based methods, proposed for recovering microalgae biomass, have limitations in practical applications. The difficulty in managing filter-cloth porosity leads to fouling and inefficiency, posing obstacles for industrial scalability. This study demonstrated that these challenges can be overcome by employing diatomite (DE) as a precoating material for the filtration. In plate and frame filter press, the effects of DE-precoating on harvesting efficiency was assessed. The optimal applied concentration of DE was 250-500 mg/L, resulting in 15-20% increase in the efficiency. Moreover, DE-precoating improved fouling resistance, increased permeate flux, and extended operational cycle times. Pilot-scale trials processing 1-5 m³ of Chlorella sp. culture showed scale-up potentials, consistent performances, and high reproducibility over multiple filtration cycles. Energy consumption was 2.5-3.0 kWh/m³, lower than that of conventional centrifugation. Overall, DE-precoating provide a robust, economically viable, energy-efficient, and easily scalable filtration process, suitable for the sustainable and high-yield harvesting of large-scaled microalgae biomass.