Development of microspheres using water hyacinth (Eichhornia crassipes) for treatment of contaminated water with Cr(VI)

The chemical contamination of water is increasingly evident, and the lack of alternatives for water treatment is one of the main problems that leads to the contamination of rivers, lagoons, wetlands and others. The biomass of Eichhornia crassipes is an alternative, since it retains heavy metals due to its great bioadsorption capacity in its vegetal structure. The objective of this research is to develop microspheres with dry and pulverized biomass of the roots E. crassipes, combining them with sodium tripolyphosphate for the adsorption of chromium from the waters of tanneries. The pH, the initial concentration and the ideal amount of these microspheres were evaluated together with the adsorption isotherms and the second-order adsorption model. There was an interesting capacity of chromium(VI) adsorption of 7.7 mg/g. The best adjusted isotherm model was the Langmuir model, and the different eliminations were adjusted to a second-order adsorption model, demonstrating that this process of adhesion is governed by a chemisorption process. It was concluded that those microspheres are one alternative for treatment of water contaminated with different heavy metals and could be used in great-scale industry.