The low-cost hybrid sorbents for immoblization of dyes: sorbents features characterization

The occurrence of dyes in wastewater is a threat for environment and living organisms. Therefore many studies have focused on investigation of diverse sorption materials to develop effective adsorption methods of removing these organic compounds (Yagub et al., 2014). Among the wide range of materials, the low-cost sorbents such as clay minerals, fly ash or lignite have received unflagging interest. However, the novel approach is to mix low-cost sorbents, clay minerals with fly ash or lignite, which could promote efficiency of removing chemically varied dyes and impact the modification of sorbent mixtures properties. Thus, the aim of this study is to investigate and compare features of hybrid sorbents: halloysite-fly ash, palygorskite-lignite before and after sorption reactions of selected dyes and evaluate influence of modified properties on their sorption mechanism. The obtained reactions’ products, as well as hybrid and selected raw sorbents after reactions, were studied by Fourier-transform infrared spectroscopy (FTIR), thermal analysis (DTA/TG) coupled with the measurement of evolved gases composition by mass spectrometer (QMS). The morphology of raw sorbents was analyzed by scanning electron microscopy (SEM) equipped with an energy dispersive spectrometer (EDS) for elemental microanalysis. The results show that sorbents features, especially the presence of organic functional groups, negative surface charges, have distinct impact on their sorption behaviour. Each componnent of hybrid sorbents affects the efficiency of dyes sorption. The obtained results revealed that mixing of various low-cost sorption materials may present unexpected properties.

 

Acknowledgments.

The studies results have been presented with the partial financial support from the EU project of POWR.03.02.00-00-I038/16-00.

Literature:

Yagub M. T., Kanti Sen T., Afroze S., Ang H.M. (2014) Dye and its removal from aqueous solution by adsorption: A review, Advances in Colloid and Interface Science, 209, p. 172-184.