UTILIZAÇÃO DA BIOMASSA DE CASCAS DE CAFÉ (coffea arabica) COMO BIOSSORVENTE PARA A REMOÇÃO DO AGROQUÍMICO Diuron® DE MATRIZES AQUOSAS

Abstract

The industrial development and the excessive use of agrochemicals has grown in recent years, consequently leading to an increase in the rate of contamination of natural resources. Brazil is among the countries that most consume agrochemicals, which leads to high contamination of soils and waters, thus causing numerous harms, which permeate among humans, fauna and flora. For minimize these impacts, studies has been performed to use agricultural residues to remove these contaminants. The use of biosorbents has been one of the viable alternatives for this purpose, since it causes a viable and low cost purpose for this waste, which would previously can be discarded. The present work aimed to evaluate the biomass capacity of the peels of the cultivar Obatã Vermelho (CV) of arabica coffee (Coffea arabica) as an adsorbent for the removal of the agrochemical Diuron® (3- (3,4-dichlorophenyl) -1,1- dimethylurea) in aqueous medium. To obtain the adsorbent material, the coffee fruits were collected at the Federal Institute Goiano - Campus Ceres, then, they had the peel separated from the seeds and washed with abundant water, to remove dirt and other interferents in the peel. The analytical technique used to measure adsorption was spectrophotometry in the UV-Vis region. The methods consisted of changing variables such as adsorbent mass, pH and agitation. It was observed that the alkalized biomass showed the bestter adsorption capacity. The better conditions were obtained at pH 2, agrochemical concentration of 12 mg L-1, in a system without agitation and with mass of 10 mg. The model that best showed the optimal process conditions was pseudo-second order, which reached equilibrium within 40 minutes.