Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Jul 25;25(15):3380.
doi: 10.3390/molecules25153380.

Impact of the Oxidant Type on the Efficiency of the Oxidation and Removal of Iron Compounds from Groundwater Containing Humic Substances

Izabela Krupińska  1
Affiliations

Impact of the Oxidant Type on the Efficiency of the Oxidation and Removal of Iron Compounds from Groundwater Containing Humic Substances

Izabela Krupińska. Molecules. .

Abstract

Due to the coexistence of organic matter and iron in groundwater, a certain part of the iron is present as iron-organic complexes in the form of colloids and/or dissolved complexes. The study was conducted to evaluate the impact of the type of oxidizing agent: O2, Cl2, H2O2, or KMnO4, on the efficiency of the oxidation and removal of iron compounds from three groundwaters with significantly different contents and types of organic substances among which humic and fulvic acids occurred. This study shows that after the aeration and the oxidation with Cl2 and H2O2, the increasing content of dissolved hydrophilic organic substances containing aromatic rings in the raw water reduced the effectiveness of Fe(II) oxidation and the effectiveness of iron removal during the sedimentation process. This regularity was not found only when KMnO4 was used as the oxidant. After oxidation with H2O2, the highest number of organo-iron complexes and an increased concentration of dissolved organic carbon were found. High concentrations of organo-ferrous connections were also found in aerated water samples. The highest KMnO4 efficiency of removing iron and organic substances and reducing the color intensity and turbidity was due to the catalytic and adsorptive properties of the precipitated MnO2, which also improved the sedimentation properties of the resultant oxidation products.

Keywords: aeration; chemical oxidation; groundwater; iron-organic complexes; organic substances.

PubMed Disclaimer

Conflict of interest statement

The author declares no conflict of interest.

Figures

Figure 1
Figure 1
Iron-organic complexes [16].
Figure 2
Figure 2
The IR spectra of humic and fulvic acids extracted from the groundwater.
Figure 3
Figure 3
The impact of the type of oxidant and values of the co-occurrence coefficient of organic substances and total iron (D and D’), SUVA254 coefficient, and hydrophilic organic content (%) on the oxidation efficiency of Fe(II) to Fe(III).
Figure 4
Figure 4
The impact of the type of oxidant and values of the co-occurrence coefficient of organic substances and total iron (D and D’), SUVA254 coefficient, and the content of hydrophilic organic substances (%) on the apparent color of water.
Figure 5
Figure 5
The influence of the type of oxidant and values of the co-occurrence coefficient of organic substances and total iron (D and D’), SUVA254 coefficient, and the content of hydrophilic organic substances (%) on water turbidity.
Figure 6
Figure 6
The influence of the type of oxidant and values of the co-occurrence coefficient of organic substances and total iron (D and D‘), SUVA254 coefficient value, and the content of hydrophilic organic substances (%) on the concentration of total iron in water after sedimentation.
Figure 7
Figure 7
The influence of the type of oxidant and values of the co-occurrence coefficient of organic substances and total iron (D and D’), SUVA254 coefficient value, and hydrophilic organic content (%) on the efficiency of TOC removal from water in the sedimentation process.
Figure 8
Figure 8
The influence of the type of oxidant and values of the co-occurrence coefficient of organic substances and total iron (D and D’), SUVA254 value, and the content of hydrophilic organic substances (%) on the amount of iron-organic complexes in water after the sedimentation process.
See this image and copyright information in PMC

References

    1. Albrektiene R., Rimeika M., Lubyte E. The removal of iron-organic complexes from drinking water using coagulation process [CD]; Proceedings of the 8th International Conference “En-vironmental Engineering”; Vilnius, Lithuania. 19–20 May 2011; pp. 509–512.
    1. Krupińska I., Kowalczyk W., Szczepaniak G. Effect of coexistence ratio of organic substances and total iron in groundwater on its treatment efficacy. Ochr. Sr. 2013;35:27–34.
    1. Albrektiene R., Rimeika M., Grazeniene R. Organic fractions and metal-organic complexes in the groundwater [CD]; Proceedings of the 9th International Conference “Environmental Engineering”; Vilnius, Lithuania. 22–23 May 2014; pp. 1–7.
    1. Urbanowska A., Kabsch-Korbutowicz M. Characteristics of natural organic matter removed from water along with its treatment. EPE. 2016;42:183–195. doi: 10.37190/epe160213. - DOI
    1. Frimmel F.H. Aquatic Humic Substances. In: Hofrichter M., Steinbüchel A., editors. Biopolymers: Biology, Chemistry, Biotechnology, Applications. Volume 1 Wiley VCH Verlag GmbH & Co. KGaA; Weinheim, Germany: 2001. Lignin Humic Substances and Coal.

LinkOut - more resources