Surface patterns of mortar plates influence Spirulina platensis biofilm attached cultivation: Experiment and modeling

Substrata selection is a key problem for engineering application of microalgae biofilm attached cultivation technology. In this work, 40 kinds of mortar plates with different surface patterns were fabricated and evaluated using Spirulina platensis biofilm cultivation. Results show surface patterns have great influences on S. platensis cultivation behaviors. Surface pitted patterns have the highest algal holding capacities, furrowed patterns are the second and bossed patterns are the lowest. After three days of cultivation, furrow patterned mortar plates have the fastest growth rate ranging at 13– 15 g m−2 d−1, the highest surface coverage ratio over 99 % and the strongest water erosion resistibility. Pit patterned mortar plates are the second, while surface bossed patterns are the worst, having the slowest grow rate, only 85–93 % surface coverage and more than 40– 50 % water erosion ratio. The surface furrow patterned mortar plates are the best engineerable supporting materials for S. platensis biofilm attached cultivation. A mathematical model has been constructed and successfully simulated the complex processes of S. platensis biofilm cultivation from inoculation adhesion, growth to biofilm development and water erosion.