TY - JOUR
T1 - Biological iron nitrogen cycle in ecological floating bed
T2 - Nitrogen removal improvement and nitrous oxide emission reduction
AU - Sun, Shanshan
AU - Gu, Xushun
AU - Zhang, Manping
AU - Tang, Li
AU - He, Shengbing
AU - Huang, Jungchen
N1 - Funding Information:
This work is financially supported by the National Natural Science Foundation of China (51678356), the National Key R&D Program of China (2017YFC0506003), and the Program for Chinese National Key Projects of Water Pollution Control and Reclamation (2017ZX07205003).
Funding Information:
This work is financially supported by the National Natural Science Foundation of China ( 51678356 ), the National Key R&D Program of China ( 2017YFC0506003 ), and the Program for Chinese National Key Projects of Water Pollution Control and Reclamation (2017ZX07205003).
Publisher Copyright:
© 2020 Elsevier Ltd
PY - 2021/1/1
Y1 - 2021/1/1
N2 - Ecological floating beds (EFBs) have become a superior method for treating secondary effluent from wastewater treatment plant. However, insufficient electron donor limited its denitrification efficiency. Iron scraps from lathe cutting waste consist of more than 95% iron could be used as electron donors to enhance denitrification. In this study, EFBs with and without iron scraps supplementation (EFB-Fe and EFB, respectively) were conducted to explore the impacts of iron scraps addition on nitrogen removal, nitrous oxide (N2O) emissions and microbial communities. Results showed the total nitrogen (TN) removal in EFB-Fe improved to 79% while that in EFB was 56%. N2O emission was 0–6.20 mg m−2 d−1 (EFB-Fe) and 1.74–15.2 mg m−2 d−1 (EFB). Iron scraps could not only improve nitrogen removal efficiency, but also reduce N2O emissions. In addition, high-throughput sequencing analysis revealed that adding iron scraps could improve the sum of denitrification related genera, among which Novosphingobium accounted for the highest proportion (6.75% of PFe1, 4.24% of PFe2, 3.18% of PFe3). Iron-oxidizing bacteria and iron-respiring bacteria associated with and nitrate reducing bacteria mainly concentrated on the surface of iron scraps. Principal co-ordinates analysis (PCoA) indicated that iron scraps were the key factor affecting microbial community composition. The mechanism of iron scraps enhanced nitrogen removal was realized by enhanced biological denitrification process. Iron release dynamic from iron scraps was detected in bench-scale experiment and the electron transfer mechanism was that Fe0 transferred electrons directly to NO3−-N, and biological iron nitrogen cycle occurred in EFB-Fe without secondary pollution.
AB - Ecological floating beds (EFBs) have become a superior method for treating secondary effluent from wastewater treatment plant. However, insufficient electron donor limited its denitrification efficiency. Iron scraps from lathe cutting waste consist of more than 95% iron could be used as electron donors to enhance denitrification. In this study, EFBs with and without iron scraps supplementation (EFB-Fe and EFB, respectively) were conducted to explore the impacts of iron scraps addition on nitrogen removal, nitrous oxide (N2O) emissions and microbial communities. Results showed the total nitrogen (TN) removal in EFB-Fe improved to 79% while that in EFB was 56%. N2O emission was 0–6.20 mg m−2 d−1 (EFB-Fe) and 1.74–15.2 mg m−2 d−1 (EFB). Iron scraps could not only improve nitrogen removal efficiency, but also reduce N2O emissions. In addition, high-throughput sequencing analysis revealed that adding iron scraps could improve the sum of denitrification related genera, among which Novosphingobium accounted for the highest proportion (6.75% of PFe1, 4.24% of PFe2, 3.18% of PFe3). Iron-oxidizing bacteria and iron-respiring bacteria associated with and nitrate reducing bacteria mainly concentrated on the surface of iron scraps. Principal co-ordinates analysis (PCoA) indicated that iron scraps were the key factor affecting microbial community composition. The mechanism of iron scraps enhanced nitrogen removal was realized by enhanced biological denitrification process. Iron release dynamic from iron scraps was detected in bench-scale experiment and the electron transfer mechanism was that Fe0 transferred electrons directly to NO3−-N, and biological iron nitrogen cycle occurred in EFB-Fe without secondary pollution.
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U2 - 10.1016/j.envpol.2020.115842
DO - 10.1016/j.envpol.2020.115842
M3 - Article
C2 - 33120338
AN - SCOPUS:85093670756
SN - 0269-7491
VL - 268
JO - Environmental Pollution
JF - Environmental Pollution
M1 - 115842
ER -