We’re excited to share that our latest work, “Nanobubble-enabled Foam Fractionation to Remove Freshwater Microalgae and Microcystin”, has been published in Bioresource Technology!
👨🔬 First author: Yihan Zhang
👨🏫 Corresponding author: Wen Zhang
🔗https://doi.org/10.1016/j.biortech.2025.133351
This study evaluated the use of nanobubble-enabled foam fractionation for the removal of Microcystis aeruginosa and three microcystin congeners (MC-LR, MC-RR, MC-YR). Foam was generated using air nanobubbles combined with surfactants—cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and chitosan—to enhance foamability and stability. Among the tested surfactants, CTAB exhibited the highest foamability, yielding improved removal performance. Removal of microcystins was influenced by both the presence of microalgae and surfactant conditions. MC-RR showed higher removal in the absence of microalgae (43.2 ± 1.5% to 56.8 ± 2.0%) compared to when algae was present (27.0 ± 5.6% to 28.3 ± 3.3%), suggesting competition during foam separation. Among the three congeners, the most hydrophobic MC-LR exhibited the highest foam affinity, with a removal efficiency of 77.4 ± 9.2%. Test results from real lake water suggests that background contaminants in lake water compete with target pollutants for adsorption onto foam bubbles, decreasing system efficiency at lower surfactant doses. These findings provide new insights into integrating nanobubble-enhanced foam fractionation into water treatment systems for mitigating harmful algal blooms (HABs) and microcystins.
Grateful for the support from a subaward of the NOAA Prevention, Control and Mitigation of HABs (PCMHAB) award (NA22NOS4780172) to the University of Maryland Center for Environmental Studies (UMCES) through the US HAB Control Technologies Incubator (US HAB-CTI), a partnership between the National Oceanic and Atmospheric Administration (NOAA), UMCES and Mote Marine Laboratory. Authors would like to thank the project mentors Allen, Taylor Armstrong, Liz Longstreet and Kevin Claridge.