Simultaneous Biological and Chemical Removal of Sulfate and Fe(II)EDTA-NO in Anaerobic Conditions and Regulation of Sulfate Reduction Products

Abstract

In the simultaneous flue gas desulfurization and denitrification by biological combined with chelating absorption technology, SO 2 and NO are converted into sulfate and Fe(II)EDTA-NO which need to be reduced in biological reactor. Increasing the removal loads of sulfate and Fe(II)EDTA-NO and converting sulfate to elemental sulfur will benefit the application of this process. A moving-bed biofilm reactor was adopted for sulfate and Fe(II)EDTA-NO biological reduction. The removal efficiencies of the sulfate and Fe(II)EDTA-NO were 96% and 92% with the influent loads of 2.88 kg SO 4 2− ·m −3 ·d −1 and 0.48 kg NO·m −3 ·d −1 . The sulfide produced by sulfate reduction could be reduced by increasing the concentrations of Fe(II)EDTA-NO and Fe(III)EDTA. The main reduction products of sulfate and Fe(II)EDTA-NO were elemental sulfur and N 2 . It was found that the dominant strain of sulfate reducing bacteria in the system was Desulfomicrobium. Pseudomonas, Sulfurovum and Arcobacter were involved in the reduction of Fe(II)EDTA-NO.

Biological Reduction of Nitric Oxide for Efficient Recovery of Nitrous Oxide as an Energy Source

“…In branch 2, the relative abundance of genera M10–M16 increased at low concentration of Fe­(II)­EDTA–NO but decreased at higher NO levels. Most genera in branch 1 were reported to be conventional denitrifying bacteria and able to completely reduce nitrate to N 2 , such as Dokdonella and Ferruginibacter, − while most genera in branch 2 were related to partial denitrification such as NO reduction or the reaction with Fe­(II) and Fe­(III), such as Rhizobium and Desulfuromonas. − Genera in branch 3 were found to be the dominant bacterial community in the denitrification process, especially biological NO reduction with Fe­(II)­EDTA as the chelating agent, such as Pseudomonas. − Overall, the diversity at the genus level decreased with the increasing levels of Fe­(II)­EDTA–NO.…”

A review: Biological technologies for nitrogen monoxide abatement

“…Furthermore, the elemental sulfur produced can be applied to agri-cultural and industrial sectors. For example, Zhang et al (2019b) achieved 78% of elemental sulfur when the SO 2− 4 concentration in the influent was 15 mM. The conversion of elemental sulfur from Fe(II)EDTA − NO 2− and sulfide occurred via the sulfur autotrophic denitrification process, as follows:…”

“…Manconi et al (2006) studied the simultaneous abatement of SO x and NO through batch tests to assess the influence of SO 2 in various NO treatment systems. In continuous systems, the integration of SO 2 and NO removal has been studied in one-stage systems such as the BTF (van der Zhang et al, 2008a), RDB (Chen et al, 2016a(Chen et al, , 2019, and moving-bed biofilm reactor (MBBR) (Zhang et al, 2019b). Two-stage systems have also been tested (Xu et al, 2022;Zhou et al, 2013b).…”

“…and Escherichia coli in a BTF that was inoculated with activated sludge from a municipal wastewater treatment plant, which led to a maximum removal capacity of 18.78 g NO m − 3 h − 1 during 5 h of operation at the steady state. Furthermore, Chen et al (2016aChen et al ( , 2019 and Zhang et al (2019b) showed that Pseudomonas, Sulfurovum, and Arcobacter were present in denitrification processes, whereas Desulfovibrio and Desulfomicrobium were present in sulfate reduction processes. Chen et al (2015b) enriched Desulfovibrio sp.…”

Spectrophotometric Determination of Fe(II)EDTA-NO, Fe(II)EDTA/Fe(III)EDTA in Chemical Absorption-Biological Reduction Integrated NO_x Removal System

“…The chemical absorption-biological reduction (CABR) integrated NO x removal system well integrates biological treatment with physicochemical methods, which improves the mass transfer of NO by adding a chelating agent [7]. It obtained a rapid development in recent years attribute to these advantages [8][9][10]. Much research has been performed on this approach including the choice of chelating agent, microbial strains, kinetics, and the optimal parameters of the bioreactor [11][12][13].…”