Mixotrophic denitrification using pyrite and biodegradable polymer composite as electron donors
Yunmeng Pang1, Liang Hu2, Jianlong Wang1
1Laboratory of Environmental Technology, INET, Tsinghua University, Beijing 100084, PR China; Beijing Key Laboratory of Radioactive Waste Treatment, INET, Tsinghua University, Beijing 100084, PR China.
Bioresource Technology
|March 21, 2022
Summary
A novel mixotrophic system using pyrite and a biodegradable polymer composite significantly enhanced nitrate removal by 37%. This innovative approach leverages synergistic microbial interactions for efficient wastewater treatment.
Area of Science:
- Environmental microbiology
- Biogeochemical cycles
- Wastewater treatment technologies
Background:
- Nitrate pollution is a major environmental concern requiring effective removal strategies.
- Mixotrophic systems offer potential for enhanced denitrification by combining different metabolic pathways.
- Pyrite and biodegradable polymers are explored as sustainable electron donors for denitrification.
Purpose of the Study:
- To investigate the denitrification performance of a novel mixotrophic system using pyrite (FeS2) and a biodegradable polymer composite (PLA/PHBV/rice hulls, PPRH).
- To elucidate the underlying microbial mechanisms and biogeochemical cycling involved in this system.
Main Methods:
- Experimental operation of a mixotrophic denitrification system.
- X-ray Photoelectron Spectroscopy (XPS) for surface analysis.
- PICRUSt2 for microbial function prediction.
- Network analysis for microbial community interactions.
Main Results:
- The mixotrophic system achieved a 37% higher average nitrate removal rate compared to single heterotrophic and autotrophic systems.
- XPS analysis revealed sulfate, sulfide, and Fe(III) formation on pyrite.
- PICRUSt2 indicated enrichment of S-oxidation, denitrification, and carbon fixation genes.
- Network analysis showed synergistic interactions among diverse microbial groups.
Conclusions:
- The pyrite/PPRH mixotrophic system demonstrates superior denitrification efficiency.
- Autotrophic S-oxidizing denitrification significantly contributes to nitrate removal.
- Synergistic microbial interactions are crucial for the system's performance.
- This study offers insights into C, N, S, and Fe cycling in such systems.
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