Abstract

In this study, the effects of Hg2+ shock on the removal efficiencies for organic matters and nutrient, enzyme activities, and microbial community structures in lab-scale sequencing batch reactor (SBR) were investigated. The results showed that the short-term exposure (6 h) to Hg2+ at 0.05 mM significantly reduced the removal efficiencies of dissolved organic carbon (DOC), ammonium-nitrogen (NH4 +-N) and orthophosphate (PO4 3--P). At lower concentration (0.01 mM) and prolonged (30 days) exposure condition, NH4 +-N removal was severely inhibited, and it was recovered after 15 days of restoration. Higher levels of reactive oxygen species (ROS), catalase (CAT) and superoxide dismutase (SOD) activities were detected in the Hg2+ shocked reactor and eventually restored to the control level after 60 days of restoration. No increase in the release of lactate dehydrogenase (LDH) was observed under both short-term and long-term shock conditions, indicating no irreversible damage to the cell membrane. The relative abundance of genus Zoogloea and Paracoccus were decreased after Hg2+ shock, which implies these microorganisms may be sensitive to heavy metal exposure.

Details

Title
The effects of mercury shock on the performance and microorganisms in biological wastewater treatment process
Author
Wang, D Q 1 ; Li, X X 2 ; Yang, Z J 2 ; Liu, T 2 ; Chai, G D 2 ; Tang, G 2 ; Zheng, X 2 ; Lin, Y S 3 

 Shaanxi Key Laboratory of Water Resources and Environment, Xi’an University of Technology, Xi’an, Shaanxi 710048, China; State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi’an University of Technology, Xi’an, Shaanxi 710048, China 
 State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi’an University of Technology, Xi’an, Shaanxi 710048, China 
 State Key Laboratory of Pollution Control & Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China 
Publication year
2019
Publication date
Oct 2019
Publisher
IOP Publishing
ISSN
17551307
e-ISSN
17551315
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2558001272
Copyright
© 2019. This work is published under http://creativecommons.org/licenses/by/3.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.