scholarly journals Correction to: Organic matter degradation state affects dissimilatory nitrate reduction processes in Knysna estuarine sediment, South Africa

Author(s):  
Yongkai Chang ◽  
Lijun Hou ◽  
Dengzhou Gao ◽  
Min Liu ◽  
Cheng Liu ◽  
...  
2021 ◽  
Vol 206 ◽  
pp. 104815
Author(s):  
Yinghui Jiang ◽  
Guoyu Yin ◽  
Lijun Hou ◽  
Min Liu ◽  
Dengzhou Gao ◽  
...  

2016 ◽  
Vol 36 (5) ◽  
Author(s):  
杨杉 YANG Shan ◽  
吴胜军 WU Shengjun ◽  
蔡延江 CAI Yanjiang ◽  
周文佐 ZHOU Wenzuo ◽  
朱同彬 ZHU Tongbin ◽  
...  

Author(s):  
Huiping Xu ◽  
Guanghua Lu ◽  
Chenwang Xue

The nitrogen pollution of rivers as a global environmental problem has received great attentions in recent years. The occurrence of emerging pollutants in high-altitude rivers will inevitably affect the dissimilatory nitrate reduction processes. In this study, sediment slurry experiments combined with 15N tracer techniques were conducted to investigate the influence of pharmaceutical and personal care products (alone and in combination) on denitrification and the anaerobic ammonium oxidation (anammox) process and the resulting N2O release in the sediments of the Yarlung Zangbo River. The results showed that the denitrification rates were inhibited by sulfamethoxazole (SMX) treatments (1–100 μg L−1) and the anammox rates decreased as the SMX concentrations increased, which may be due to the inhibitory effect of this antibiotic on nitrate reducing microbes. 2-Ethylhexyl-4-methoxycinnamate (EHMC) impacted nitrogen transformation mainly though the inhibition of the anammox processes. SMX and EHMC showed a superposition effect on the denitrification processes. The expression levels of the denitrifying functional genes nirS and nosZ were decreased and N2O release was stimulated due to the presence of SMX and/or EHMC in the sediments. To the best of our knowledge, this study is the first to report the effects of EHMC and its mixtures on the dissimilatory nitrate reduction processes and N2O releases in river sediments. Our results indicated that the widespread occurrence of emerging pollutants in high-altitude rivers may disturb the nitrogen transformation processes and increase the pressure of global warming.


2013 ◽  
Vol 10 (11) ◽  
pp. 6851-6864 ◽  
Author(s):  
G. D. Song ◽  
S. M. Liu ◽  
H. Marchant ◽  
M. M. M. Kuypers ◽  
G. Lavik

Abstract. Benthic nitrogen transformation pathways were investigated in the sediment of the East China Sea (ECS) in June of 2010 using the 15N isotope pairing technique. Slurry incubations indicated that denitrification, anammox and dissimilatory nitrate reduction to ammonium (DNRA) as well as intracellular nitrate release occurred in the ECS sediments. These four processes did not exist independently, nitrate release therefore diluted the 15N labeling fraction of NO3−, and a part of the 15NH4+ derived from DNRA also formed 30N2 via anammox. Therefore, current methods of rate calculations led to over and underestimations of anammox and denitrification respectively. Following the procedure outlined in Thamdrup and Dalsgaard (2002), denitrification rates were slightly underestimated by an average 6% without regard to the effect of nitrate release, while this underestimation could be counteracted by the presence of DNRA. On the contrary, anammox rates calculated from 15NO3− experiment were significantly overestimated by 42% without considering nitrate release. In our study, this overestimation could only be compensated 14% by taking DNRA into consideration. In a parallel experiment amended with 15NH4++14NO3−, anammox rates were not significantly influenced by DNRA due to the high background of 15NH4+ addition. The significant correlation between potential denitrification rate and sediment organic matter content (r = 0.68, p < 0.001, Pearson) indicated that denitrification was regulated by organic matter, while, no such correlations were found for anammox and DNRA. The relative contribution of anammox to the total N-loss increased from 13% at the shallowest site near the Changjiang estuary to 50% at the deepest site on the outer shelf, implying the significant role of anammox in benthic nitrogen cycling in the ECS sediments, especially on the outer shelf. N-loss as N2 was the main pathway, while DNRA was also an important pathway accounting for 20–31% of benthic nitrate reduction in the ECS. Our study demonstrates the complicated interactions among different benthic nitrogen transformations and the importance of considering denitrification, DNRA, anammox and nitrate release together when designing and interpreting future studies.


Sign in / Sign up

Export Citation Format

Share Document