Title |
Cr(VI) removal from aqueous solution by thermophilic denitrifying bacterium Chelatococcus daeguensis TAD1 in the presence of single and multiple heavy metals |
Author |
Han Li1, Shaobin Huang1,2*, and Yongqing Zhang1 |
Address |
1College of Environment and Energy, South China University of Technology, Guangzhou 510006, P. R. China, 2Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, Guangzhou 510006, P. R. China |
Bibliography |
Journal of Microbiology, 54(9),602-610, 2016,
|
DOI |
10.1007/s12275-016-5295-5
|
Key Words |
thermophilic denitrifying bacterium, Cr(VI) removal,
aqueous solution, heavy metals, cellulose acetate microspheres |
Abstract |
Cr(VI) pollution is increasing continuously as a result of ongoing
industrialization. In this study, we investigated the
thermophilic denitrifying bacterium Chelatococcus daeguensis
TAD1, isolated from the biofilm of a biotrickling filter used
in nitrogen oxides (NOX) removal, with respect to its ability
to remove Cr(VI) from an aqueous solution. TAD1 was capable
of reducing Cr(VI) from an initial concentration of
10 mg/L to non-detectable levels over a pH range of 7–9 and
at a temperature range of 30–50°C. TAD1 simultaneously
removed both Cr(VI) and NO3
−-N at 50°C, when the pH
was 7 and the initial Cr(VI) concentration was 15 mg/L.
The reduction of Cr(VI) to Cr(III) correlated with the growth
metabolic activity of TAD1. The presence of other heavy
metals (Cu, Zn, and Ni) inhibited the ability of TAD1 to remove
Cr(VI). The metals each individually inhibited Cr(VI)
removal, and the extent of inhibition increased in a cooperative
manner in the presence of a combination of the metals.
The addition of biodegradable cellulose acetate microspheres
(an adsorption material) weakened the toxicity of the heavy
metals; in their presence, the Cr(VI) removal efficiency returned
to a high level. The feasibility and applicability of simultaneous
nitrate removal and Cr(VI) reduction by strain
TAD1 is promising, and may be an effective biological method
for the clean-up of wastewater. |