ESTUDO DO EQUILíBRIO E DA DIN MICA DA BIOSSOR O DO íON CáDMIO PELA MACRóFITA LEMNA MINOR EM COLUNA DE LEITO FIXO

This study aimed to evaluate the Lemna minor in natura and pretreated biomass efficiency in thecadmium removal from synthetic solutions. The macrophyte pretreatment was performed using sodiumhydroxide and sulfuric acid solutions separately at 0,1M and 0,01M. The sodium hydroxide solution(0,1M) pretreatment achieved the best outcome. In addition, there were carried out experimental tests inorder to obtain equilibrium data from a batch system and evaluation of the cadmium removal dynamics ina fixed bed column. Experimental equilibrium data were obtained at 30oC and initial pH at 5. Cadmiumremoval tests were performed in a fixed bed column at five different flow rates: 5, 6, 7, 8 and 9 mL/min.Langmuir, Freundlich and Sips models were applied to equilibrium data modeling. Sips isotherm fitted bestthe experimental equilibrium data. Maximum removal capacity obtained by the batch reactor system wasequivalent to 0,861 meq/g. For the cadmium removal dynamics modeling there was applied a model thattakes into account mass transfer on solid phase. The rate of adsorption was described using a linear drivingforce model (FML).The applied model described adequately the experimental rupture curves behavior.