AVALIAÇÃO DO POTENCIAL BIOSSORVENTE DA BIOMASSA DE CASCAS DE ABACAXI PARA REMOÇÃO DE AGROQUÍMICO EM MATRIZES AQUOSAS

Abstract

The pollution of natural resources due to environmental impacts caused by various human activities, especially in the industrial and agricultural sectors, such as the incorrect disposal of contaminants in the environment, are the main aggravating factors for contamination of these resources. Therefore, it is necessary to use alternative methods of treatment of these contaminants, and one of these techniques is through the use ofbioadsorbents, as an alternative to conventional methods. Thus, the present work investigated the potential of pineapple (Ananas comosus) peels biomass as adsorbent in the removal of Diuron® herbicide in aqueous matrices. Initially, after chemical modification of material, the physicochemical properties of the in natura and NaOH-treated adsorbent were investigated. The zero charge point characterization (pHpcz), the medium infrared spectroscopy with Fourier transform (mid-FTIR) and thermogravimetric analysis, were analysed. Adsorption assays were performed to verify the influence of the chemical modification of biomassa and pH's on the adsorption, using the modified and in natura samples in pH`s range (2 to 10) in concentration 8 mg.L-1 of the herbicide. The results indicated an increase in adsorption capacity to pH values between 8 and 10 using the alkalinized sample. To optimize adsorbent quantity, concentration and contact time, a complete factorial design 23was performed using fixed pH (10), volume (10 mL) and time (h). The best results were obtained with adsorbent mass (40 mg) in concentration 4 mg.L-1 and without agitation. The kinetic study performed had a maximum adsorption capacity corresponding to 0.870 mg.g-1 indicating contact time equilibrium of 240 min. The kinetic model that better adjusted to dataset was the was the pseudo first order. Finally, for the isothermal analyzes the Langmuir model presented the better adjusted to the experimental dataset with maximum adsorption capacity of 0.5636 mg.L-1. Thus, the biosorbent material investigate showed favorable results for the removal of up to 88% of Diuron® herbicide in aqueous solutions.