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[Anaerobic Reduction Process Characteristics and Microbial Community Analysis for Sulfate and Fe(Ⅱ) EDTA-NO/Fe(Ⅲ)
Yu Zhang1, Fang Wan1, Ji-Ti Zhou1
1Key Laboratory of Industrial Ecology and Environmental Engineering(MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
Huan Jing Ke Xue= Huanjing Kexue
|July 3, 2018
Summary
This study introduces a novel biological flue gas desulfurization (Bio-FGD) and denitrification method using chelating absorption. The process effectively removes sulfur dioxide (SO2) and nitrogen oxides (NOx) with high efficiency in an anaerobic reactor.
Area of Science:
- Environmental Biotechnology
- Chemical Engineering
- Microbiology
Background:
- Traditional flue gas treatment methods face challenges in efficiency and environmental impact.
- Biological flue gas desulfurization (Bio-FGD) and biological regeneration technologies offer promising alternatives.
- Simultaneous removal of sulfur dioxide (SO2) and nitrogen oxides (NOx) is crucial for industrial emissions control.
Purpose of the Study:
- To develop and evaluate a combined chelating absorption and biological regeneration process for simultaneous SO2 and NOx removal.
- To investigate the removal efficiencies of SO2 and NOx byproducts, specifically sulfate (SO4^2-) and Fe(II) EDTA-NO, in an anaerobic reactor.
- To identify the microbial communities responsible for the reduction of byproducts and the regeneration of the chelating agent.
Main Methods:
- Utilized an alkaline absorption liquid containing Fe(II) EDTA to capture SO2 and NO from flue gas.
- Employed an anaerobic reactor to simultaneously remove SO4^2- and Fe(II) EDTA-NO byproducts.
- Monitored removal efficiencies under controlled hydraulic residence time (HRT) and pH, and identified microbial populations using genetic analysis.
Main Results:
- Achieved average removal efficiencies of 95.16% for SO4^2- and 96.61% for Fe(II) EDTA-NO at optimal HRT (16 h) and pH (7.0).
- Identified the primary reduction products as sulfide (S^2-) and hydrogen sulfide (H2S) for SO4^2-, and nitrogen gas (N2) for Fe(II) EDTA-NO.
- Observed effective regeneration of Fe(III) EDTA, with reduction rates dependent on HRT, and identified key microbial genera including *Desulfomicrobium*, *Pseudomonas*, *Sulfurimonas*, *Sulfurovum*, *Thermovirga*, and *Mesotoga*.
Conclusions:
- The combined chelating absorption and biological regeneration process is highly effective for simultaneous SO2 and NOx removal from flue gas.
- Optimized operating conditions (HRT and pH) and a diverse microbial community are critical for efficient byproduct removal and system regeneration.
- This integrated approach presents a sustainable and efficient solution for industrial emissions control.
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