Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7476935 | Journal of Environmental Management | 2018 | 11 Pages |
Abstract
Fe(II)-mediated autotrophic denitrification in the presence of copper (Cu), nickel (Ni) and zinc (Zn) with four different microbial cultures was investigated in batch bioassays. In the absence of metals, complete nitrate removal and Fe(II) oxidation were achieved with a Thiobacillus-dominated mixed culture and Pseudogulbenkiania sp. 2002 after 7â¯d. A nitrate removal of 96 and 91% was observed with a pure culture of T. denitrificans and an activated sludge enrichment, respectively, after 10â¯d of incubation. Cu, Ni and Zn were then supplemented at an initial concentration of 5, 10, 20 and 40â¯mg Me/L. A decrease of approximately 50% of the soluble metal concentrations occurred in the first 4â¯d of denitrification, due to metal precipitation, co-precipitation, sorption onto iron (hydr)oxides, and probably sorption onto biomass. A higher sensitivity to metal toxicity was observed for the microbial pure cultures. Pseudogulbenkiania sp. 2002 was the least tolerant among the biomasses tested, resulting in only 6, 8 and 6% nitrate removal for the highest Cu, Ni and Zn concentrations, respectively. In contrast, the highest nitrate removal efficiency and specific rates were achieved with the Thiobacillus-dominated mixed culture, which better tolerated the presence of metals. Averagely, Cu resulted in the highest inhibition of nitrate removal, followed by Zn and Ni.
Related Topics
Physical Sciences and Engineering
Energy
Renewable Energy, Sustainability and the Environment
Authors
Kyriaki Kiskira, Stefano Papirio, Chloé Fourdrin, Eric D. van Hullebusch, Giovanni Esposito,