Lignite as functional materiál for removal of pollutants from water

presentation, poster

English

Water regime is nature is strongly affected by climatic changes as an increase in temperature and connected decrease in river flows. It means that a potential input of pollutants cannot be sufficiently diluted, and their concentrations can increase above safe limits. It is necessary to solve this problem and strive to remove pollutants from natural and waste waters as well as to reduce their inputs in nature. Lignite as yang coal can be used as a cost-effective and environmental-friendly material for the removal of pollutants from nature. In addition, lignite is rich in humic substances are also considered as sorbent with high capacity and efficiency of adsorption. In this contribution, lignite was used as a functional material for the removal of several types of pollutants from water. Simultaneously, humic acids as the most active constituents of lignite, were isolated from lignite and used as an adsorbent for metal ions, nitrates, and phosphates. The pollutants were chosen on the basis of a screening of pollutants in water closed to Brno as well as our experiences with sorption experiments. Traditional batch adsorption experiments with lignite and humic acids were realized. As expected, the efficiency of adsorption was higher in the case of humic acids. On the other hand, lignite is more suitable in economic terms, because the isolation of humic acids from lignite constitutes additional costs. Interactions between lignite (humic acids) and pollutants have a complex nature given by their heterogeneous, polyelectrolyte and polydispersive character, e.g. metal ions can bond in several different ways – from the purely electrostatic, non-specific interaction of metal cation with the net negative charge on the surface of a humic particle to specific interactions in the formation of complexes and chelates with functional groups. Due to the heterogeneous character of lignite (humic acids) they can form water-soluble and water insoluble complexes with different bond strengths. Thus, pollutants can exist in lignite (humic) material in several different fractions. Desorption experiments, realized in this work, provided the fractionation into free movable particles of pollutants and pollutants immobilized in lignite (humic) structure which were not leached from the adsorbent materials. This work was supported by the project FAST/FCH-J-23-8283 financed by Brno University of Technology.

lignite; humic acid; pollutant; adsorption; desorption

KLUČÁKOVÁ, M.; ZÁVODSKÁ, P.; PAVLÍKOVÁ, M.; BURŠÍK, L.; SOBOTKOVÁ, V.

6. 8. 2023

PONTIFICIA UNIVERSIDAD CATOLICA DE CHILE

Santiago

1