Carvão ativado produzido a partir do endocarpo de coco da baía (Coccus Nucifera) aplicado no tratamento de efluente têxtil

Abstract

This study investigated the treatment of an industrial textile effluent by combined physicochemical processes, coagulation/flocculation - activated carbon. Trials in Jar-Test using the same time for mixing and sedimentation, have improved organic matter and pollutants removal efficiency from the effluent for the coagulants (Al2(SO4)3 e FeCl3) employed. The treatment characterization for optimum concentration found was measured through the determination of SST, DBO, DQO, COT, nitrate, turbidity and surfactants content. For the parameters investigated, the percent removal in accordance with the best optimization trial were 85.6%, 88.9% and 96.2% for DQO, DBO and turbidity, respectively, using the coagulant FeCl3. For the adsorptive treatment of the pre-treated textile effluent, activated carbons were produced the endocarp of coconut (Coccus Nucifera), with chemical activated using Al2(SO4)3 and physical one using water vapor (steam). The ratio of activator:precursor effect on the activation were analyzed, as well as the carbonization temperature, retention time and type of activation on the textural properties of the activated carbons produced. The activated carbons were characterized by N2 adsorption to determine: SBET, SM, VP, VM, VMS and D. The CAQ232FQ carbon showed higher microporosity and SBET (1009 m2.g-1), and it was used in adsorption experiments. The CAQ232FQ carbon was also characterized by: MEV, Boehm, FTIR, TG, DTA, pH, pHPCZ and apparent density. Adsorption experiments with CAQ232FQ carbon were made for pre-treated textile effluent and synthetic sewage. The pH was not adjusted during the adsorption and the temperature was maintained at 26 ºC. The isotherms obtained for both effluents are better adapted to Freundlich model, however, adsorption processes for the pre-treated industrial effluent follows the kinetic model of pseudo-second order, differently to the synthetic industrial effluent which follows model of pseudo-first order. As a concluding remark, adsorption tests with CAQ232FQ carbon have proved to be effective for color removal, considering that the adsorption rate of the dye was higher than 97% in both effluents and the reduction rate of the analyzed parameters was higher than 99% for the industrial textile effluent.