IDEAS home Printed from https://ideas.repec.org/a/gam/jsusta/v17y2025i2p481-d1563750.html
   My bibliography  Save this article

Presence of Humic Acids in Landfill Leachate and Treatment by Flocculation at Low pH to Reduce High Pollution of This Liquid

Author

Listed:
  • Carlos Costa

    (Chemical Engineering Department, Faculty of Chemical Sciences, University of Salamanca, Plaza de la Merced s/n, 37008 Salamanca, Spain)

  • M. Laura Pinedo

    (Chemical Engineering Department, Faculty of Chemical Sciences, University of Salamanca, Plaza de la Merced s/n, 37008 Salamanca, Spain)

  • Brayan D. Riascos

    (Chemical Engineering Department, Faculty of Chemical Sciences, University of Salamanca, Plaza de la Merced s/n, 37008 Salamanca, Spain)

Abstract

Humic substances are abundant in landfill leachate, especially humic acids, which are insoluble at low pH in aqueous solutions. Focusing on the chemical properties of humic acids, we describe in this work a new method for a sustainable treatment of landfill leachate originated from solid wastes, which consists of the reduction of organic load (COD, chemical oxygen demand) and colour and is based in the gradual decrease in pH to the value in which HAs are insoluble in water solution. Zeta potential values mark the chemical stage of humic acids because of ionisation–protonation of the phenolic and carboxylic groups, and this parameter is monitored during flocculation, changing from −16.8 mV at pH 7.7 to 0.0068 mV at pH 2.0, when HAs precipitate. The final result is the reduction in the organic matter content (COD) and colour in the leachate, 86.1% and 84.7%, respectively. Solids produced by precipitation during the acidification treatment have been characterized by elemental chemical analysis and Fourier transform infrared spectrometry, concluding a high similarity in chemical composition with commercial and natural humic acids. Protonated humic acids at low pH can interact with other molecules by hydrogen bonds and form bigger molecular structures much more unstable in suspension, which conduct to precipitation. The mean diameter of the humic acids aggregates was measured, detecting the formation of big molecular structures at low pH. This process is analysed and compared economically with other processes proposed for landfill leachate treatment, resulting in a promising technique for the management of this residue.

Suggested Citation

  • Carlos Costa & M. Laura Pinedo & Brayan D. Riascos, 2025. "Presence of Humic Acids in Landfill Leachate and Treatment by Flocculation at Low pH to Reduce High Pollution of This Liquid," Sustainability, MDPI, vol. 17(2), pages 1-15, January.
  • Handle: RePEc:gam:jsusta:v:17:y:2025:i:2:p:481-:d:1563750
    as

    Download full text from publisher

    File URL: https://www.mdpi.com/2071-1050/17/2/481/pdf
    Download Restriction: no

    File URL: https://www.mdpi.com/2071-1050/17/2/481/
    Download Restriction: no
    ---><---

    References listed on IDEAS

    as
    1. Arailym Kamal & Ardak Makhatova & Bakzhan Yergali & Aigerim Baidullayeva & Aliya Satayeva & Jong Kim & Vassilis J. Inglezakis & Stavros G. Poulopoulos & Elizabeth Arkhangelsky, 2022. "Biological Treatment, Advanced Oxidation and Membrane Separation for Landfill Leachate Treatment: A Review," Sustainability, MDPI, vol. 14(21), pages 1-32, November.
    2. Magdalena Daria Vaverková & Jakub Elbl & Eugeniusz Koda & Dana Adamcová & Ayla Bilgin & Vojtěch Lukas & Anna Podlasek & Antonín Kintl & Małgorzata Wdowska & Martin Brtnický & Jan Zloch, 2020. "Chemical Composition and Hazardous Effects of Leachate from the Active Municipal Solid Waste Landfill Surrounded by Farmlands," Sustainability, MDPI, vol. 12(11), pages 1-20, June.
    Full references (including those not matched with items on IDEAS)

    Most related items

    These are the items that most often cite the same works as this one and are cited by the same works as this one.
    1. Hegazy Rezk & A. G. Olabi & Mohammad Ali Abdelkareem & Abdul Hai Alami & Enas Taha Sayed, 2023. "Optimal Parameter Determination of Membrane Bioreactor to Boost Biohydrogen Production-Based Integration of ANFIS Modeling and Honey Badger Algorithm," Sustainability, MDPI, vol. 15(2), pages 1-13, January.
    2. Wojciech Rykała & Monika J. Fabiańska & Dominika Dąbrowska, 2022. "The Influence of a Fire at an Illegal Landfill in Southern Poland on the Formation of Toxic Compounds and Their Impact on the Natural Environment," IJERPH, MDPI, vol. 19(20), pages 1-22, October.
    3. Xinyang Liu & Yu Wang, 2022. "Identification and Assessment of Groundwater and Soil Contamination from an Informal Landfill Site," Sustainability, MDPI, vol. 14(24), pages 1-16, December.
    4. Anna Podlasek & Aleksandra Jakimiuk & Magdalena Daria Vaverková & Eugeniusz Koda, 2021. "Monitoring and Assessment of Groundwater Quality at Landfill Sites: Selected Case Studies of Poland and the Czech Republic," Sustainability, MDPI, vol. 13(14), pages 1-20, July.

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:gam:jsusta:v:17:y:2025:i:2:p:481-:d:1563750. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a bibliographic reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: MDPI Indexing Manager (email available below). General contact details of provider: https://www.mdpi.com .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.