The document summarizes a meta-analysis that compared the nitrate removal performance of different substrates used in denitrifying bioreactors. It found that wood media had the highest nitrate removal rate (NRR) and percentage (NRE), followed by mulch media, nutshell-based media, and inorganic media. However, when considering cost-effectiveness, woodchip and corn cob were the most economical natural organic carbon substrates. Overall, the analysis suggests that mulch media is the optimal material for nitrate removal due to its low cost and potential to overcome deficiencies in other media types.

1. Global Significance of Substrates for Nitrate Removal in
Denitrifying Bioreactors Revealed by Meta-analysis
Yuchuan
Fan
(Postdoc)
Aug, 31 2022
Department of Soil, Water, and Ecosystem Sciences,
University of Florida

2. D O C U M E N T T I T L E |
S E C T I O N T I T L
Outline
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Section Item | Section Item | Section
Item Section Item | Section
Item
Media
Soil
Soil
Denitrifying bioreactor
NO3
-
Sand layer
Nitrate
-laden
N2
 Introduction
 Performance
 Mechanism
 Cost analysis

3. NO3
N2
N2
N2 N2
N2
NO3
NO3
NO3
NO3
D O C U M E N T T I T L E |
S E C T I O N T I T L
Denitrifying
bioreactor
(DNBR)
Question: Which filling material is better?

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Materials &
Methods
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Item

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Bioreactor
types
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Item Section Item | Section
Item

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Media
taxonomy
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8. D O C U M E N T T I T L E |
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Indicators
Where VT are influent water (m3), Nin and Nout are the inflow and
outflow nitrate concentrations (mg N L-1), VBR is the total volume
of the DNBR (m3), and t represents operation time (day).
NRR =
𝑉𝑇 𝑁𝑖𝑛 − 𝑁𝑜𝑢𝑡
VBR × 𝑡
NRE =
𝑁𝑖𝑛 − 𝑁𝑜𝑢𝑡
𝑁𝑖𝑛
(g N m-3 d-1)
(%)

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Performance
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Performance
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Item Section Item | Section
Item

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S E C T I O N T I T L
Performance
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Item Section Item | Section
Item

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Mechanism
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Cost
analysis
SubEcoi
=
NRRi
Pricei
(g N m-3 d-1)
($ m-3)
(g N $-1 d-1)

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Conclusions
 Our meta-analysis conducted a comparative assessment among
the substrate and indicated that nitrate removal (NRE & NRR)
in descending order were: NNC>MM>NC>IM.
 Our cost-effective index (SubEco) showed that woodchip and
corn cob was more economical than other NCs or NNCs.
 From a holistic review, we suggest MM as the optimum
material for nitrate removal due to the low cost and great
potential to make up media’s deficiencies.
Take home message:

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Questions
y.fan@ufl.edu
https://denitrifying-bioreactor.webnode.page