Utilização do pó de serragem como adsorvente alternativo na remoção de verde de malaquita

Abstract

This study aimed to evaluate the efficiency of using sawdust as an alternative adsorbent for the removal of malachite green in aqueous solution . For this, removal kinetic tests were performed and built the adsorption isotherms according to the models of Freundlich , Langmuir and Temkin . Kinetic study used 7 g of sawdust in solution containing malachite green with initial concentration of 9.0 mg L-1 and initial pH of 4.22 . The adsorption time ranged from 0 to 90 min. The highest removal percentage achieved in the experiment was 94.6 % . The model of Lagergren of pseudo-second order showed better agreement with experimental data on the adsorption of the malachite green dye, with a correlation coefficient of 0.9936 and more approximate results between the experimental and calculated values of biosorbed amount at equilibrium ( qe ). In the biosorptionisotherms , 0.30 g of the biosorbent mass was added to 15 ml of an aqueous solution containing malachite green in different initial concentrations of 0, 3, 6, 12 , 20 and 25 mg L-1. The Freundlich isotherm model best described the behavior of the experimental data , with an R2 of 0.9117 . The Langmuir model was not able to fit the experimental data , showing R2 of 0.2031.The maximum experimental biosorption capacity ( qm ) of malachite green to sawdust was 1.53 mg g -1 .