TY - JOUR
T1 - Effects of HRT and water temperature on nitrogen removal in autotrophic gravel filter
AU - Xu, Jing hang
AU - He, Sheng bing
AU - Wu, Su qing
AU - Huang, Jung Chen
AU - Zhou, Wei li
AU - Chen, Xue chu
N1 - Funding Information:
This research was supported by the National Natural Science Foundation of China (No. 51378306 ) and Education Ministry's New Century Excellent Talents Supporting Plan ( NCET-11-0320 ) and Zhejiang Provincial Key Lab for Water Environment and Marine Biological Resources Protection. I would like to thank Dr. Sheng-bing He and Dr, Jung-Chen Huang, for his assistance in research guides.
Publisher Copyright:
© 2016 Elsevier Ltd.
PY - 2016/3/1
Y1 - 2016/3/1
N2 - Organic Carbon added to low ratio of carbon to nitrogen (C/N ratio) wastewater to enhance heterotrophic denitrification performance might lead to higher operating costs and secondary pollution. In this study, sodium thiosulfate (Na2S2O3) was applied as an electron donor for a gravel filter (one kind of constructed wetland) to investigate effects of hydraulic retention time (HRT) and water temperature on the nitrate removal efficiency. The results show that with an HRT of 12 h, the average total nitrogen (TN) removal efficiencies were 91% at 15-20 °C and 18% at 3-6 °C, respectively. When HRT increased to 24 h, the average TN removal increased accordingly to 41% at 3-6 °C, suggesting denitrification performance was improved by extended HRT at low water temperatures. Due to denitrification, 96% of added nitrate nitrogen (NO3--N) was converted to nitrogen gas, with a mean flux of nitrous oxide (N2O) was 0.0268-0.1500 ug m-2 h-1, while 98.86% of thiosulfate was gradually converted to sulfate throughout the system. Thus, our results show that the sulfur driven autotrophic denitrification constructed wetland demonstrated an excellent removal efficiency of nitrate for wastewater treatment. The HRT and water temperature proved to be two influencing factors in this constructed wetland treatment system.
AB - Organic Carbon added to low ratio of carbon to nitrogen (C/N ratio) wastewater to enhance heterotrophic denitrification performance might lead to higher operating costs and secondary pollution. In this study, sodium thiosulfate (Na2S2O3) was applied as an electron donor for a gravel filter (one kind of constructed wetland) to investigate effects of hydraulic retention time (HRT) and water temperature on the nitrate removal efficiency. The results show that with an HRT of 12 h, the average total nitrogen (TN) removal efficiencies were 91% at 15-20 °C and 18% at 3-6 °C, respectively. When HRT increased to 24 h, the average TN removal increased accordingly to 41% at 3-6 °C, suggesting denitrification performance was improved by extended HRT at low water temperatures. Due to denitrification, 96% of added nitrate nitrogen (NO3--N) was converted to nitrogen gas, with a mean flux of nitrous oxide (N2O) was 0.0268-0.1500 ug m-2 h-1, while 98.86% of thiosulfate was gradually converted to sulfate throughout the system. Thus, our results show that the sulfur driven autotrophic denitrification constructed wetland demonstrated an excellent removal efficiency of nitrate for wastewater treatment. The HRT and water temperature proved to be two influencing factors in this constructed wetland treatment system.
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U2 - 10.1016/j.chemosphere.2015.12.136
DO - 10.1016/j.chemosphere.2015.12.136
M3 - Article
C2 - 26766357
AN - SCOPUS:84957795999
SN - 0045-6535
VL - 147
SP - 203
EP - 209
JO - Chemosphere
JF - Chemosphere
ER -