Developing staggered woven mesh aerator with three variable-micropore layers in recycling water pipeline to enhance CO2 conversion for improving Arthrospira growth.

A staggered woven mesh (SWM) aerator equipped with three variable-micropore layers was developed to enhance the CO2 conversion into HCO3- in a recycling water pipeline for promoting CO2 utilization efficiency and Arthrospira growth in large-scale raceway ponds. The input CO2 gas was broken into smaller bubbles (0.78- 2.43 mm) through the first-stage shear with axial rectangles, second-stage shear with radial rectangles (equivalent pore diameter = 150 µm), and third-stage shear with uniform micropores. A high-speed camera (MotionXtra HG-100K CMOS) and an Image J image processing software were employed to capture the bubble pictures. Compared to the traditional steel pipe (TSP) aerator, the bubble generation diameter and time in the SWM aerator reduced by 72.3% and 48.6%, respectively. The optimized structure (ε = 14, pore = 23 µm) of the SWM aerator promoted the carbonization efficiency and HCO3- conversion efficiency into biomass by 78.6% and 64.6% than the TSP aerator. Further, the chlorophyll fluorescence and biomass measurements showed an increase in the actual photochemical efficiency (analyzed by Hansatech FMS1 chlorophyll fluorescence instrument) and biomass yield by 1.8 times and 80.1%.