Molecular Spectroscopic Study of Water Hyacinth Dry Matter

ABSTRACT

The potential use of water hyacinth dry matter for removing heavy metals from wastewater is studied by combining various spectroscopic techniques and quantum chemical ab initio calculations. The aquatic plant water hyacinth was treated with 0.025, 0.050, 0.100, 0.200, and 0.400 M acetic acid for different times up to 19.0 hours. The plant was divided into root and shoot then dried and grinded into pieces of 200 µm in diameter. FTIR measurements revealed that acetate finds its way to the plant root and is then transported to the shoot. Furthermore, it is shown that the treated and dried plant can be used to mediate Cd from wastewater. FAAS results indicate that 55% of Cd (in case of low concentration) and 80% of Cd (in case of higher concentration) could be removed from wastewater within 2.0 hours. The coordination of acetate to the plant was assumed to happen via the cellulose of the plant where also the Cd uptake takes place. This is confirmed by studying changes in the absorption of the C=O stretching band of cellulose acetate subject to CdCl₂ by FTIR and by a cellulose monomer quantum chemical model.

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