RESUMO
The extensive use of organic molecules (Rhodamine B and Amitriptyline) also has contributed to environmental pollution; adsorption is a relevant method for removal of these contaminants in aqueous media. In this context, the objective of this study was to modify the surface of cellulose (Cel) with phosphoric acid and sodium tripolyphosphate to obtain a biopolymer with incorporated phosphate groups (PCel). The modification was confirmed by X-ray dispersive energy spectroscopy, solid state nuclear magnetic resonance, X-ray diffraction, and thermal analysis. The obtained material (PCel) was used as a Rhodamine B (RhB) or Amitriptyline (AmTP) adsorbent, and the highest adsorption capacity of this material was obtained at pH 3.0 (RhB) and 7.0 (AmTP) and the equilibrium time was achieved at 65 (RhB) and 150 min (AmTP). Moreover, the pseudo-first-order model best describes the kinetics of this adsorption. The experimental adsorption isotherms were adjusted to the Langmuir model, indicating that monolayer adsorption occurred and the highest experimental adsorption capacity obtained was 47.58 (RhB) and 45.52 mg g-1 (AmTP) in PCel. The thermodynamic parameters showed that the adsorption process is exothermic and non-spontaneous, with increase of non-spontaneity with enhance of the temperature. However, PCel was efficient in removing the contaminant (RhB or AmTP) in an aqueous solution.
Assuntos
Amitriptilina/química , Biopolímeros/química , Celulose/química , Rodaminas/química , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Polifosfatos , Temperatura , Termodinâmica , Água/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Difração de Raios XRESUMO
In the last years has increased the study about the using of natural biopolymers and theirs derivatives in the removal (adsorption/incorporation) of contaminats of medium aqueous, and theirs utilization in the desorption (release) de drugs. However, there not in the literature studies about the utilization of the cellulose and cellulose phosphate in the adsorption (incorporation)/desorption (release) of the drug amitriptyline (AMI). Therefore, in this study was accomplished the synthesized of the phosphated cellulose (PC) through the reaction of pure cellulose (C) with sodium trimetaphosphate (P) under-reflux, for 4h and at 393K. The efficiency of the reaction was observed by XRD, TG/DTG, (31)P NMR and EDS. The adsorption study for the AMI in aqueous medium was carried out by varying the time, pH, concentration, temperature and ionic strength. The results showed that the PC showed a greater adsorption capacity of AMI than pure cellulose, presenting an increase of about 102.72% in the adsorption capacity of the drug by cellulose after the phosphating reaction. In desorption of drug from the surface of biomaterials was performed by varying the pH and time, where it was observed that PC showed a maximum release of 40.98% ± 0.31% at pH 7.