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Updated: Jan 4, 2026
Extraction of Structural Extracellular Polymeric Substances from Aerobic Granular Sludge
Published on: September 26, 2016
Interaction between perfluorooctanoic acid and aerobic granular sludge.
Guojing Yang1, Ni Zhang2, Jingnan Yang3
1College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, 315100, PR China; College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China.
Perfluorooctanoic acid (PFOA) is partially removed by aerobic granular sludge primarily through adsorption, not biodegradation. This PFOA uptake negatively impacts sludge settleability and crucial nutrient removal processes.
Area of Science:
- Environmental Science
- Environmental Chemistry
- Wastewater Treatment
Background:
- Perfluorooctanoic acid (PFOA) is increasingly used, raising environmental toxicity concerns.
- The interaction between PFOA and aerobic granular sludge (AGS) is not well understood.
- AGS is a vital component in advanced wastewater treatment systems.
Purpose of the Study:
- To investigate the fate of PFOA in AGS systems at environmentally relevant concentrations.
- To assess the impact of PFOA on AGS structure, function, and microbial communities.
- To elucidate the removal mechanisms of PFOA by AGS.
Main Methods:
- Experimental studies using AGS reactors exposed to varying PFOA concentrations (0.1–1.0 mg/L).
- Mass balance analysis and X-ray photoelectron spectroscopy (XPS) for PFOA fate and adsorption mechanisms.
- Settleability tests, nutrient removal efficiency measurements (N and P), and microbial community analysis (16S rRNA gene sequencing).
- Analysis of extracellular polymeric substances (EPS) using Fourier-transform infrared spectroscopy (FTIR) and XPS.
Main Results:
- AGS removed 32.0%–36.4% of PFOA, primarily via adsorption (inhomogeneous multilayer adsorption).
- PFOA significantly inhibited sludge settleability and biological nutrient removal (N and P), with 1.0 mg/L PFOA reducing key processes by up to 60%.
- PFOA altered AGS morphology, increased EPS, affected EPS functional groups, inhibited polyhydroxyalkanoates and glycogen cycling, and reduced the abundance of key microbial groups like Nitrosomonas and Nitrospira.
Conclusions:
- Adsorption is the dominant PFOA removal mechanism by AGS, but it leads to significant operational issues.
- PFOA poses a substantial risk to the performance of AGS wastewater treatment systems.
- Further research is needed to mitigate PFOA's adverse effects on AGS and ensure effective wastewater treatment.
