<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>Nitrate(V) ions in surface water and sewage are pollutants, which excessive concentration have a negative impact on aquatic ecosystems. Due to the chemical properties, removal of nitrates from wastewater is a difficult process. In the municipal sector, biological denitrification (activated sludge) is the most commonly used process. However, in the case of industrial wastewater, where inhibiting substances or substances toxic to microorganisms are present in wastewater, it is necessary to use other types of methods.</p>
<p>It is possible to distinguish here methods based on physicochemical processes, in particular: physicochemical separation, chemical or electrochemical reduction and oxidation under supercritical conditions. At present, membrane methods and ion exchange processes are used mainly in the industrial sector because of the high knowledge of the technology and the amount of applications used. Intensive studies are also being carried out on methods using chemical reduction processes, where greatest advantage is the ability to transform nitrates to neutral molecular nitrogen.</p>
</abstract>

Nitrate(V) ions in surface water and sewage are pollutants, which excessive concentration have a negative impact on aquatic ecosystems. Due to the chemical properties, removal of nitrates from wastewater is a difficult process. In the municipal sector, biological denitrification (activated sludge) is the most commonly used process. However, in the case of industrial wastewater, where inhibiting substances or substances toxic to microorganisms are present in wastewater, it is necessary to use other types of methods.
It is possible to distinguish here methods based on physicochemical processes, in particular: physicochemical separation, chemical or electrochemical reduction and oxidation under supercritical conditions. At present, membrane methods and ion exchange processes are used mainly in the industrial sector because of the high knowledge of the technology and the amount of applications used. Intensive studies are also being carried out on methods using chemical reduction processes, where greatest advantage is the ability to transform nitrates to neutral molecular nitrogen.

PHYSICOCHEMICAL METHODS OF NITRATES REMOVAL FROM WASTEWATER

Architecture, Civil Engineering, Environment

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

{"article-title":"PHYSICOCHEMICAL METHODS OF NITRATES REMOVAL FROM WASTEWATER"}

Nitrate(V) ions in surface water and sewage are pollutants, which excessive concentration have a negative impact on aquatic ecosystems. Due to the chemical...

Reducing agent	E°, V	pH	Nitrogen conversion products	Other by-products	Process indicators
Al (metal)	-2.30	Alkaline	NH₂, NO_2^-, N₂	Al.(OH)₃	-
Fe (metal)	-0.037	Acidic	NO_2-	Fe³⁺	-
Fe (metal)	-0.771	Alkaline	N₂	Fe₂O₃, OH^-	-
Zn (metal)	-1.245	Alkaline	NH₃, NO_2-, N₂	Zn(OH)₂	Catalysator
NH_4⁺	+0.27	Acidic	N₂O, N₂	-	High pressure and temperature, Cl^- ions
HCO₂H	-0.199	Acidic	N₂O, N₂, NH₃	CO₂	Rh/C
HCO₂H		Acidic	N₂	CO₂, H₂	High pressure and temperature
CH₃OH	+0.017	Acidic	NH₄+	HCO_3^-	High pressure and temperature
NH₃OH⁺	-0.05	Acidic	N₂O	-	-
NH₂OH	-1.05	Alkaline	N₂O	OH^-	Cu²⁺
Fe²⁺	+0.771	Acidic	NO, N₂O, N₂	Fe³⁺	-
Fe²⁺	-0.56	Alkaline	NH₃	Fe(OH)₃, OH^-	Cu²⁺, Ag⁺

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	Ti/Pt	1.00	100	23.8	-	76.2%
3	Ti/IrO₂	0.50	100	17.3	ammonia	82.7%
4	Ti/IrO₂	0.75	100	22.6	-	77.4%

PHYSICOCHEMICAL METHODS OF NITRATES REMOVAL FROM WASTEWATER

Article Category: research-article

Data publikacji: 18 paź 2019

Zakres stron: 153 - 159

Otrzymano: 17 lip 2019

Przyjęty: 18 sie 2019

DOI: https://doi.org/10.21307/acee-2019-046

Słowa kluczowe
Chemical reduction, Chemical denitrification, Nitrates, Nitrates removal

© 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.

Figure 2.

Figure 3.

Reducing agents for nitrate chemical reduction, [5]

Effectiveness of electrochemical reduction in the presence of NaCl solution, [12]

PHYSICOCHEMICAL METHODS OF NITRATES REMOVAL FROM WASTEWATER

Article Category: research-article

Data publikacji: 18 paź 2019

Zakres stron: 153 - 159

Otrzymano: 17 lip 2019

Przyjęty: 18 sie 2019

DOI: https://doi.org/10.21307/acee-2019-046

Słowa kluczoweChemical reduction, Chemical denitrification, Nitrates, Nitrates removal

© 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.

Figure 2.

Figure 3.

Reducing agents for nitrate chemical reduction, [5]

Effectiveness of electrochemical reduction in the presence of NaCl solution, [12]

Słowa kluczowe
Chemical reduction, Chemical denitrification, Nitrates, Nitrates removal