Indole-3-Acetic Acid-Assisted Microalgal Biofilm for High-Efficiency Wastewater Purification: Biomass Densification and Pollutant Removal Kinetics
Year: 2026
Type: article
Abstract: The enhancement of startup and performance in a Tetradesmus obliquus-polyurethane sponge biofilm system was investigated via the regulation of the phytohormone Indole-3-acetic acid (IAA). IAA supplementation at 1 and 5 mg/L increased biofilm biomass and chlorophyll a content, with the maximum biofilm biomass reaching 48.2 mg/g, and improved nutrient removal performance under shock-loading conditions, particularly for total nitrogen (TN) and total phosphorus (TP). IAA treatment was associated with EPS remodeling, including an increase in the protein/polysaccharide ratio to 0.68 and a 16% enrichment in tryptophan-like protein components. These EPS-related changes coincided with a decrease in the absolute zeta potential to −2.49 mV, which may be relevant to enhanced initial biofilm development. The corresponding EPS-related changes were characterized by three-dimensional excitation–emission matrix (3D-EEM) and Fourier transform infrared (FTIR) analyses using representative concentrations. Furthermore, the IAA-treated biofilm showed improved resilience under low, medium, and high loading conditions, with the most favorable TN removal reaching 87% at 1 mg/L IAA. These results suggest that IAA supplementation at 1 and 5 mg/L can promote microalgal biofilm start-up and improve nutrient-removal resilience under the tested conditions, with 5 mg/L showing the strongest response in biofilm growth and structural characterization.
Source: Water
DOI: 10.3390/w18070805
Authors: Qun Wei, Fu Pang, Dan Zhao, Wenxi Chu, Ziming Pan, Xiangmeng Ma
Institution: Guangxi University
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,137
Award: G1762963072
OpenAlex ID: W7141267858
FWCI:
Cites:
Cited by:
Related to: