Análise da ação da paligorsquita no tratamento de efluentes contaminados por chumbo.

Abstract

With the rapid development of modern industries, the environment has faced more contamination, and one of the main pollutants are metal ions Therefore, new wastewater treatment techniques are required. to that it is possible to combine low costs with efficiency and environmental preservation. Among In many processes, adsorption has become widely researched for use in wastewater. contaminated by heavy metals. Clays have great potential as adsorbents. Among these, there is the paligorsquita that adsorbs many cations because of its porous structure due to its large specific surface. In this research, the potential of Guadalupe-PI paligorsquita adsorption was evaluated with lead ion adsorbent. Initially, a mapping of a certain area identify the points of occurrence of the paligorsquita. Subsequently, three samples of clays with different proportions in paligorsquita composition. THE The objective was to evaluate the influence of contaminants such as kaolinite and quartz on of lead sorption. With the choice of the purest paligorsquita, two Activation methods: a) by hydrochloric and sulfuric acids at concentrations of 2, 4 and 6 mol L "at 25 ° and 90 ° C for 2 and 4 h and (b) the temperature with intervals of 100 - 900 ° C for 24 hours. All activated samples were DRX, FRX, FTIR, SEM, BET, CTC and TG / DSC thermally activated) for the purpose of observing the changes caused by the acid and heat treatments. Subsequently, they were tested on lead ion adsorption. The changes were more pronounced at stricter acid concentrations such as XRD showed a decrease in the intensity of the clay mineral reflection. These changes were confirmed in FRX with the leaching of some oxides and with the increased SiCK concentrationA significant increase in specific surface area was observed in samples treated with 6.0 mol.L "1.2h, 90h C HCl and H2SO4. main changes occurred after heat treatment on the surface of the clay mineral refer to water losses from the structure as physically adsorbed water, zeolitic water and coordination water. Above 500 ° C condensation began to occur silanols and aluminols groups and the emergence of a new phase of enstatite. The Best adsorption results occurred at 500 ° C. Presented the best adsorption results samples C906M2 (43.42 mg g "1); S906M2 (52.30 mg g" 1); and P500 (43.30 mg g "1); The adsorption kinetics of these samples followed the kinetic model. of pseudo second order. The experimental equilibrium data fit well with Freundlich's isotherm. This characterizes that Pb2 + adsorption occurs on surfaces heterogeneous paligorsquita, as well as the natural paligorsquita researched in this job. The value of sorption capacity was greatly affected by the pH and dose of clay.