Estudo da contaminação por ferro de águas subterrâneas provenientes da região noroeste do estado do Paraná

Abstract

The maintenance of water distributed for human consumption is indispensable to maintain the standards of Potability, once that currently the reserves of drinking water have decreased considerably because of the various human interventions on the planet, as the increasing pollution of spring water by the man’s neglect for the generation and disposal of polluting substances. One of the consequences of this neglect is contamination of underground water supply by metals in the form of dissolved ions in water, as well as the iron, that despite not being characterized as a essentially toxic substance can cause problems to the public water supply, by depositing in pipelines and by changing water properties such as color and flavor. And by the fact that the excessive consumption also causes health problems by accumulating in the skin tissues during aging, causing neurological disorders, such as Alzheimer's And Parkinson's Disease. To reverse these problems it is necessary to develop methods aimed at the removal of heavy metals from water, by simple and rentals mechanisms. To this end, the biosorbents obtained by reuse of agricultural residues such as straw and husks of grains and seeds, which can be a viable alternative for the treatment of water by treating of materials of high availability, low cost and reduce the environmental impact of its disposal because they are traditionally burned. In this work, studies were carried out regarding the adsorptive potential of the agricultural waste, corn straw, wheat straw, soybean straw and soybean hulls. The biosorbent was kept in contact with an iron solution of known concentration, the iron content being measured periodically in order to ascertain the decrease in the concentration of this heavy metal as a function of time. This same study was also carried out with these biosorbents after their chemical modification with EDTA, aiming to intensify the adsorptive potential of the material because it is a hexadentate chelating agent that retains metallic ions inside their structure. The incorporation of the EDTA was confirmed by a series of analyzes which aimed the characterization of the biosorbent’s chemical structure, through Infrared spectroscopy with Fourier transform, total nitrogen content analysis and mass gain analysis. Proving the incorporation of the EDTA by all analyzes performed. Regarding the kinetic study, it was observed that the non-modified biosorbent materials presented efficiency of removal of up to 80% of the metal present in solution, while the modified biosorbent presented efficiency of removal of up to 95% because of the incorporation of the EDTA in this structure. In this way, the biosorbent materials developed have high adsorptive potential for iron metal ions.