Análisis experimental de la capacidad de la goma de tara (Caesalpinia spinosa) para la remoción de cadmio y plomo

Abstract

In the current research, the capacity of tara gum (Caesalpinia spinosa) for the removal of cadmium and lead in samples of contaminated water under laboratory conditions was experimentally analyzed, the concentrations were 1 ppm of Cd and 3 ppm of Pb. Moreover, stock solutions of 100ppm were made by diluting 0.159g of Pb (NO3)2 and 0.163g of CdCl2 in 1 liter of distilled water; then, the stock solutions were diluted to reach the required concentrations. Initially, the biomass was characterized by means of a FTIR analysis and physicochemical tests: color, odor, texture, moisture, pH, and ash. Regarding the quantification of adsorbed cadmium and lead, it was determined through samples taken in a set period once the biomass was added to the solutions, maintaining a constant agitation of 400rpm, the samples were analyzed by using cuvette tests with the Merck SQ21 118 photocolorimeter. Regarding the adsorption capacity, the data were evaluated by applying the mathematical models of pseudo first and second order. According to the results, the pseudo second order mathematical model was adjusted for the two elements, the removal time was evaluated resulting in a saturation point with lead and cadmium of 0.5g with a maximum removal capacity of 79.6% in 20 minutes for cadmium and for lead 69.33% removal capacity in 40 minutes of contact time. It was concluded that biomass has a higher adsorption capacity for cadmium than for lead, however for the two metals it works naturally. It is recommended that for the implementation of a small and medium-scale adsorption system, it would be appropriate to carry out a dynamic study of the conditions.