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Updated: Jan 25, 2026

Biofilm Removal Using Carbon Dioxide Aerosols without Nitrogen Purge
Published on: November 6, 2016
Enhanced biofilm formation and denitrification in biofilters for advanced nitrogen removal by rhamnolipid addition
Chong Peng1, Yilin Gao1, Xuan Fan1
1State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, PR China.
Abstract:
Denitrification biofilters (DNBFs) are widely used in advanced nitrogen removal of wastewater with low C/N and effective biofilm formation is critical to their long-term operation. Hereby the influence of rhamnolipid addition in DNBFs was investigated for the first time. Gradient concentrations (0, 20, 40, 80, 120 mg/L) of rhamnolipid were applied to investigate nitrogen removal, biofilm properties and microbial community of lab-scale DNBFs. A significant increase of nitrogen removal was observed in rhamnolipid-treated DNBFs (p < 0.05). Total solid (TS), extracellular polymeric substances (EPS) and adhesion force of biofilms in DNBF with 120 mg/L rhamnolipid reached the maximum, which were 2.17, 2.15 and 3.36 times of those in the control, respectively. Moreover, rhamnolipid exhibited an improvement in abundance of Simplicispira and Gemmatimonas which were responsible for enhanced biofilm formation and denitrification. The results suggested that rhamnolipid addition can be a novel strategy to improve the start-up and denitrification performance of DNBFs.
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