Evaluating simultaneous chromate and nitrate reduction during microbial denitrification processes

Peng, Lai, Liu, Yiwen, Gao, Shu-Hong, Chen, Xueming and Ni, Bing-Jie (2016) Evaluating simultaneous chromate and nitrate reduction during microbial denitrification processes. Water Research, 89 1-8. doi:10.1016/j.watres.2015.11.031


Author Peng, Lai
Liu, Yiwen
Gao, Shu-Hong
Chen, Xueming
Ni, Bing-Jie
Title Evaluating simultaneous chromate and nitrate reduction during microbial denitrification processes
Journal name Water Research   Check publisher's open access policy
ISSN 1879-2448
0043-1354
Publication date 2016-02-01
Year available 2015
Sub-type Article (original research)
DOI 10.1016/j.watres.2015.11.031
Open Access Status Not Open Access
Volume 89
Start page 1
End page 8
Total pages 8
Place of publication London, United Kingdom
Publisher IWA Publishing
Collection year 2016
Language eng
Formatted abstract
Sulfur-based autotrophic denitrification and heterotrophic denitrification have been demonstrated to be promising technological processes for simultaneous removal of nitrate (−NO3) and chromate (Cr (VI)), two common contaminants in surface and ground waters. In this work, a mathematical model was developed to describe and evaluate the microbial and substrate interactions among sulfur oxidizing denitrifying organism, methanol-based heterotrophic denitrifiers and chromate reducing bacteria in the biofilm systems for simultaneous nitrate and chromate removal. The concomitant multiple chromate reduction pathways by these microbes were taken into account in this model. The validity of the model was tested using experimental data from three independent biofilm reactors under autotrophic, heterotrophic and mixotrophic conditions. The model sufficiently described the nitrate, chromate, methanol, and sulfate dynamics under varying conditions. The modeling results demonstrated the coexistence of sulfur-oxidizing denitrifying bacteria and heterotrophic denitrifying bacteria in the biofilm under mixotrophic conditions, with chromate reducing bacteria being outcompeted. The sulfur-oxidizing denitrifying bacteria substantially contributed to both nitrate and chromate reductions although heterotrophic denitrifying bacteria dominated in the biofilm. The mixotrophic denitrification could improve the tolerance of autotrophic denitrifying bacteria to Cr (VI) toxicity. Furthermore, HRT would play an important role in affecting the microbial distribution and system performance, with HRT of higher than 0.15 day being critical for a high level removal of nitrate and chromate (over 90%).
Keyword Sulfur-based autotrophic denitrification
Heterotrophic denitrification
Nitrate (NO3-)
Chromate (Cr (VI))
Mathematical model
Mixotrophic conditions
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2016 Collection
Advanced Water Management Centre Publications
 
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