Simultaneous removal of NOX and SO2 from flue gas in an integrated FGD-CABR system by sulfur cycling-mediated Fe(II)EDTA regeneration
Journal
Environmental Research
Journal Volume
205
Date Issued
2022
Author(s)
Abstract
Chemical absorption-biological reduction (CABR) process is an attractive method for NOX removal and Fe(II)EDTA regeneration is important to sustain high NOX removal. In this study a sustainable and eco-friendly sulfur cycling-mediated Fe(II)EDTA regeneration method was incorporated in the integrated biological flue gas desulfurization (FGD)-CABR system. Here, we investigated the NOX and SO2 removal efficiency of the system under three different flue gas flows (100 mL/min, 500 mL/min, and 1000 mL/min) and evaluated the feasibility of chemical Fe(III)EDTA reduction by sulfide in series of batch tests. Our results showed that complete SO2 removal was achieved at all the tested scenarios with sulfide, thiosulfate and S0 accumulation in the solution. Meanwhile, the total removal efficiency of NOX achieved ?100% in the system, of which 3.2%–23.3% was removed in spray scrubber and 76.7%–96.5% in EGSB reactor along with no N2O emission. The optimal pH and S2?/Fe(III)EDTA for Fe(II)EDTA regeneration and S0 recovery was 8.0 and 1:2. The microbial community analysis results showed that the cooperation of heterotrophic denitrifier (Saprospiraceae_uncultured and Dechloromonas) and iron-reducing bacteria (Klebsiella and Petrimonas) in EGSB reactor and sulfide-oxidizing, nitrate-reducing bacteria (Azoarcus and Pseudarcobacter) in spray scrubber contributed to the efficient removal of NOX in flue gas. ? 2021 Elsevier Inc.
Subjects
Fe(II)EDTA regeneration
Flue gas
NOX
S0 recovery
SO2
edetic acid
nitric oxide
sulfate
sulfide
sulfur
sulfur dioxide
thiosulfate
accumulation
biological analysis
microbial community
regeneration
Article
Azoarcus
bacterium
chemical absorption biological reduction
chemical reaction
controlled study
Dechloromonas
denitrifying bacterium
desulfurization
flue gas
heterotrophy
Klebsiella
nonhuman
Petrimonas
Pseudarcobacter
Saprospiraceae
sulfide oxidizing bacterium
sulfur cycle
waste component removal
Type
journal article