Evaluación de la capacidad de remoción de plomo y cadmio en soluciones acuosas utilizando resinas de carbón mineral
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Marín Castro, Nellys | 2019
In the present investigation, an alternative treatment for the removal of lead and cadmium from
aqueous solutions by means of an adsorbent material made from modified mineral coal
impregnated with carbon disulphide and sodium hydroxide was considered. The material used
was chemically characterized, the effect of pH on removal, adsorption kinetics (using Lagergren
and Ho and McKay models) and Langmuir and Freundlich isotherms were evaluated in order to
evaluate the adsorption capacity of modified coal. The results of the characterization of the coal
showed that it is of metallurgical type, for its high content of volatile material and low content of
Sulphur, as well as of ashes that makes it effective for the combustion and generation of energy.
Tests to evaluate the effect of pH on adsorption determined that the best removal of lead and
cadmium was at pH 6, for both materials, with adsorption percentages of 99.75 % and 99.85% for
lead and cadmium with modified carbon and 75% and 52.5 for lead and cadmium with
unmodified carbon. Kinetic studies indicated that the adsorption process reaches equilibrium in
100 minutes with 19.95 mg/g for lead and 19.94 mg/g for cadmium, following the kinetic model
of pseudo second order for both metals. The isothermal study showed that the adsorption of Lead
and Cadmium in the modified carbon is better suited to a Freundlich isotherm. In addition, a
laboratory scale application test was performed with industrial wastewater, where removal
percentages of 99.11% and 92% of cadmium and lead, respectively, were found. This
modification shows as a result a considerable increase in the adsorption of lead and cadmium
with respect to coal, which indicates that this adsorbent is favorable for the removal of heavy
metals.
LEER