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Categoría del artículo: research-article
Publicado en línea: 18 oct 2019
Páginas: 153 - 159
Recibido: 17 jul 2019
Aceptado: 18 ago 2019
DOI: https://doi.org/10.21307/acee-2019-046
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© 2019 Maciej ŻOŁNIERCZYK et al., published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Figure 1.
![The effectiveness of chemical reduction of nitrate using nanoscale iron powder with different initial nitrate concentrations and the metal to solution ratio 4 g Fe0/dm3, [14]:](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64706f7083f1392090d6979d/j_acee-2019-046_fig_001.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20250907%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20250907T215155Z&X-Amz-Expires=3600&X-Amz-Signature=b565643790782b28ab4169362120abddcebfa6108ee55f3629422aa01bd9f3a2&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Figure 2.
![Effects of pH on nitrate removal with iron powder (160–200 mesh). Test conditions: 20 g Fe0/dm3 and 50 mg/dm3 NO3-N solutions, [5]](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64706f7083f1392090d6979d/j_acee-2019-046_fig_002.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20250907%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20250907T215155Z&X-Amz-Expires=3600&X-Amz-Signature=3b3604e16c1e93643fb5bac3fd2e5117cfcc36186195efb5900374d609656fe4&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Figure 3.
![Concentration of nitrate with iron powder (160–200 mesh). Metal to solution ratio 4 g Fe0/dm3. Initial pH 2, [5]](https://sciendo-parsed.s3.eu-central-1.amazonaws.com/64706f7083f1392090d6979d/j_acee-2019-046_fig_003.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6AP2G7AKOUXAVR44%2F20250907%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20250907T215155Z&X-Amz-Expires=3600&X-Amz-Signature=67fa1a066821840d96e7b5509c44a4f37a0c7d397a68bcf69b57ca6c4edceb68&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)
Reducing agents for nitrate chemical reduction, [5]
Reducing agent | E°, V | pH | Nitrogen conversion products | Other by-products | Process indicators |
---|---|---|---|---|---|
|
-2.30 | Alkaline | NH2, NO2- , N2 | Al.(OH)3 | - |
|
-0.037 | Acidic | NO2- | Fe3+ | - |
-0.771 | Alkaline | N2 | Fe2O3, OH- | - | |
|
-1.245 | Alkaline | NH3, NO2-, N2 | Zn(OH)2 | Catalysator |
|
+0.27 | Acidic | N2O, N2 | - | High pressure and temperature, Cl- ions |
|
-0.199 | Acidic | N2O, N2, NH3 | CO2 | Rh/C |
Acidic | N2 | CO2, H2 | High pressure and temperature | ||
|
+0.017 | Acidic | NH4+ | HCO3- | High pressure and temperature |
|
-0.05 | Acidic | N2O | - | - |
|
-1.05 | Alkaline | N2O | OH- | Cu2+ |
|
+0.771 | Acidic | NO, N2O, N2 | Fe3+ | - |
-0.56 | Alkaline | NH3 | Fe(OH)3, OH- | Cu2+, Ag+ |
Effectiveness of electrochemical reduction in the presence of NaCl solution, [12]
no. | Type of anode | NaCl concentration in solution [g/dm3] | Initial nitrate-N concentration [g/dm3] | Final nitrate-N concentration [mg/dm3] | Reaction by-products | Effectiveness |
1 | Ti/Pt | 0.75 | 100 | 24.6 | ammonia | 75.4% |
2 | 1.00 | 100 | 23.8 | - | 76.2% | |
3 | Ti/IrO2 | 0.50 | 100 | 17.3 | ammonia | 82.7% |
4 | 0.75 | 100 | 22.6 | - | 77.4% |