Abstract
The effect of nitrate concentration on denitrification rate, microbial community and byproduct accumulation in sulfide-driven autotrophic denitrification, one of the dominant processes during anoxic marine sediment remediation, was investigated in this study. Microorganisms which were phylogenetically closely related with Sulfurimonas denitrificans of ε-Proteobacteria and Thiohalomonas denitrificans of γ-Proteobacteria were the major autotrophic denitrifiers in this study. Nitrate concentration was demonstrated to have selective effect on denitrifying microbial community as revealed by denaturing gradient gel electrophoresis. Denitrifiers enriched at 30mM NO3- have higher diversity than other two groups (10, and 80mM NO3-) according to Shannon index. Denitrification showed zero-order reaction kinetics when nitrate concentration was higher than 4mM. Neither absolute nitrate concentration nor overall nitrate/sulfide ratio acted as the determinant for denitrification byproduct (i.e. N2O and NO2-) accumulation. The limitation of sulfide due to low mass transfer might be the reason for the byproduct accumulation.
Original language | English |
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Pages (from-to) | 1-6 |
Number of pages | 6 |
Journal | Chemosphere |
Volume | 83 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1 Mar 2011 |
Keywords
- Autotrophic denitrification
- Nitrate concentration
- Sediment
- Sulfurimonas denitrificans
ASJC Scopus subject areas
- Environmental Chemistry
- General Chemistry