title: Improving microalgal growth with reduced diameters of aeration bubbles and enhanced mass transfer of solution in an oscillating flow field.
abstract: A novel oscillating gas aerator combined with an oscillating baffle was proposed to generate smaller aeration bubbles and enhance solution mass transfer, which can improve microalgal growth in a raceway pond. A high-speed photography system (HSP) was used to measure bubble diameter and generation time, and online precise dissolved oxygen probes and pH probes were used to measure mass-transfer coefficient and mixing time. Bubble diameter and generation time decreased with decreased aeration gas rate, decreased orifice diameter, and increased water velocity in the oscillating gas aerator. The optimized oscillating gas aerator decreased bubble diameter and generation time by 25% and 58%, respectively, compared with a horizontal tubular gas aerator. Using an oscillating gas aerator and an oscillating baffle in a raceway pond increased the solution mass-transfer coefficient by 15% and decreased mixing time by 32%; consequently, microalgal biomass yield increased by 19%.
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors.forename: Zongbo
authors.initials: Z
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China. Electronic address: juncheng@zju.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Cheng
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors.forename: Richen
authors.initials: R
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors.forename: Junhu
authors.initials: J
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors.forename: Kefa
authors.initials: K
authors.lastname: Cen
mesh_terms: D000332:Aerobiosis; D018533:Biomass; D019149:Bioreactors; D058086:Microalgae / Q000254:growth & development*; D061005:Ponds; D012212:Rheology; D012996:Solutions; D013997:Time Factors; D014867:Water
chemical_list: D012996:Solutions; D014867:Water
keywords: Aeration bubble; Flow field; Microalgae; Oscillating; Raceway pond