Obtención de un coagulante natural modificado con nanopartículas magnéticas para el tratamiento de aguas contaminadas con mercurio

Abstract

The aim of the study was to check if the use of different dosages of a natural coagulant – flocculant based on cocoa husks – CCN – 51 (Theobroma cacao L.) with Magnetic Nanoparticles (MPNs) presents significant differences in the removal of mercury (Hg) during coagulation – flocculation processes. The applied method was based on Jar Test with water samples with 11 μg/L and 2 000 μg/L of Hg with different coagulating solutions (M1, M2, M3). The coagulant solution was obtained from cocoa powder and MPNs were provided by Analytical Chemistry laboratory at Polytechnic School of Chimborazo; both components were characterized by Near Infrared (NIR) and Scanning Electron Microscopy (SEM); additionally, for hypothesis testing, ANOVA was applied through the Statistical Package for the Social Sciences (SPSS) program. The characterization of natural coagulant – flocculant and MPNs by IR, showed the presence of functional groups: Amines, Amides, Alkenes, Alkynes, Alcohols, Fluorides, Sulfons, Sulfonyl Chlorides, Sulfates, Esters, and Bromides or lodides; On the other hand, with characterization by MEB, the particles of the natural coagulant – flocculant and the MPNs showed an average size of 1.26 μm and 0.59 μm respectively, with elliptical and irregular shapes. The highest Hg removal, in the Experimental Units (EU) with a concentration of 11 μg/L, was with M1 with an average of 68.91%, while for the EU with a concentration of 2 000 μg/L of Hg it was M2 with an average of 61.68%. It is concluded statistically that there were no significant differences in the use of different doses of coagulant solution, however, favorable percentages of up to 84.24% of Hg removal were obtained with the coagulant solution M2. This imposes the treatment used as an environmentally friendly alternative to coagulants – synthetic flocculants.