BATISTA, T. S.; ttp://lattes.cnpq.br/6836352193553269; BATISTA, Thianne Silva.
Resumo:
The process of adsorptive separation stands out as an alternative to minimize contamination problems in water and shows a broad applicability, mainly due to the use of clays as adsorbent. This study aimed to evaluate the adsorption capacity of natural and modified attapulgite clay, using this material as an adsorbent of synthetic oily wastewater. 22 factorial
experimental designs were conducted, wherein, the initial concentration of oil present in the
effluent and the stirring time were independent variables and the response variable was the oil
removal percentage. Then, the removing test was evaluated by performing a feasibility study
of the adsorption process, obtaining the adsorption mechanism through kinetics, as well as
with the definition of the model which best describes the experimental data through the
adsorption isotherm. From the characterizations performed with the attapulgite clay, it was
identified with x-ray diffraction (XRD) that its structure does not favor a shift in the intensity
of the peaks after the organophilization process, however, the spectroscopy in the infrared
(FTIR) demonstrated the presence of the organic groups confirming the insertion of the salt in
the attapulgite structure; furthermore, through scanning electron microscopy (SEM), it was
observed a fibrous morphology of the clay and N2 physisorption (BET method) indicated the
presence of mesoporous structure of natural attapulgite and macroporous of organoclay.
Adsorption tests showed that the organophilization applied to attapulgite favored the
adsorption process because a 67.57% removal of oil and an adsorption capacity of 7.23 mg of
oil per gram of clay were obtained, with the initial concentration of 100 mg.L-1 oil and a
stirring time of 1 hour. With the application of theoretical models, a coefficient of
determination of R² = 0.98 was reached, indicating a strong correlation of the second-order equation in the adsorption kinetics. For adsorption isotherm, it was found that Freundlich, Langmuir and Sigmoid BIDR equations fitted the experimental data.
