Avaliação da capacidade da concha do marisco Anomalocardia brasiliana em adsorver ferro em amostras de águas subterrâneas

Abstract

The shells of shellfish Anomalocardia brasiliana considered a biomaterial of low cost were tested in this work as bioadsorbente of iron. The shells were washed with deionized water and dried at 110 °C, then were characterized to pH, pH pzc, SBET, VM, DMP, Cz, bulk density, calcium, infrared spectroscopy and diffraction of x-ray. Were estudied the parameters of pH, mass of the biosorbent, contact time, temperature and concentration. We carried out the linear and non-linear fit to the kinetic study at concentrations of 3.00, 5.00 and 10.00 mg L-1 and adsorption equilibrium. Kinetic study using the variances of the models of pseudo-first order and pseudo-second order, at the concentrations studied, it can be seen that there is no significant difference between the two models studied. Regarding the adsorption equilibrium was found that the non-linear regression using the Langmuir Freundich models and fits the experimental data obtained for bioadsorbent, no significant difference for 95% level of confidence. The adsorptive capacity of the bioadsorbent study in equilibrium time was 1.054 mg L-1. The thermodynamic parameters were found H0 = 0.023 KJ mol-1 K-1, S0= 0.087 KJ mol-1 K-1 e G0= -2.260, -3.244, -3.999 (KJ mol-1) at temperature of 298, 308 and 318K, respectively. Percentage of removal of 88.00 and 57.32%, with a standard e with real samples, respective, showing that the biomaterial can be a viable alternative to be used in the processes of adsorption of metals.