Estudo cinético da capacidade de biossorção de metais pesados em resíduos sólidos orgânicos.

Abstract

With the technological development increases the amount of waste released by industry, in most cases without prior treatment. Therefore cause damage to the health can be transmitted to humans through environmental transport or contamination of air, soil, water and food. In developing new methods biosorption is a process which uses biomass or microorganisms, retention, removal or recovery of heavy metals. For the biosorption of nickel (II) ion were used three types of biosorbents (sewage sludge, organic solid waste and activated carbon). All reactors received a mass of 0.4 ± 0.01 g biosorbents, added 75 ml of metal solution whose initial concentration is 0.01; 0.02 and 0.05 mol Ni2+ L-1 and carried out in three experiments at different initial pH values of 4.0; 5.0 and 6.0. The initial and final pH were measured containers, calculated metal retention expressed by biosorption capacity (q) and removal efficiency (%) of the metal ion. Through the theory of Langmuir isotherm established the biosorption kinetics and used the two kinetic models used in our work: (1) pseudo-first order; and (2) pseudo-second order. The results obtained in our experiment, the pH values were approximate neutral. The biosorption capacity of nickel (II) ion revealed that the metal establishes a tendency to take up unoccupied binding sites on the surfaces of biosorbents. Biosorption efficiency obtained values close to 100% of sewage sludge in 720 minutes. The linear regression of biosorption capacity as function of contact time, occurring all R² values close to 1. Conclusion is that the results obtained in the experiment were favorable, due to its good biosorption of nickel (II) ion by biosorbents in concentration of 0.01 mol Ni2+ L-1.