-Batch experiments were carried out for biosorption of Remazol Brilliant Blue R dye onto the macrophyte Salvinia natans. Effects of parameters such as initial dye concentration, pH, biosorbent dosage, contact time and temperature were investigated. Chemical and morphological characteristics of the biosorbent were evaluated before and after the biosorption process using methods such as Optical Microscopy (OM), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TA), Differential Scanning Calorimetry (DSC) and Infrared Spectroscopy (FT-IR). Sorption kinetics were conducted and followed a pseudo-second order kinetic model. Equilibrium data were well represented by the Langmuir model. Salvinia natans exhibited a maximum uptake of 61.9 mg.g -1 . The Dubinin-Radushkevich model indicated that the adsorption takes place by a physical process. Thermodynamic parameters were estimated. The negative values of the Gibbs energy indicated the spontaneous nature of the adsorption. The entropy was positive and the positive value of the enthalpy showed that the process is endothermic.

-The performance of Salvinia natans macrophyte to recover lead and chromium from single and bicomponent solutions in batch and fixed bed systems was investigated. Equilibrium data were obtained through isotherms and fitted to Langmuir, Freundlich and D-R models for a single component system. In the fixed bed study the breakthrough curves were carried out at three different ratios of concentrations for the bicomponent study and at the concentration of 1 mmol.L -1 for the single system. In order to know the biosorption mechanism, FT-IR analyses were performed for S. natans before and after the uptake of metal ions. The results showed different functional groups in the biomass and the ability of these groups to bind Cr are not common in the literature, which makes the experimental data obtained in this work very important for providing information that could be used in adsorption processes.

The aim of this study was to evaluate the performance of two forms of basic granular activated carbon (GAC), mineral (pH = 10.5) and vegetal (pH = 9), for the removal of three pharmaceuticals, as sulphamethoxazole (SMX), diclofenac (DCF) and 17β-estradiol (E2), from two different matrices: fortified distilled (2.4-3.0 mg L(-1) and pH from 5.5 to 6.5) and natural (∼1.0 mg L(-1) and pH from 7.1 to 7.2) water in a bench scale. The Rapid Small-Scale Column Test used to assess the ability of mineral and vegetal GAC on removal of such pharmaceuticals led to removal capacities varying from 14.9 to 23.5 mg g(-1) for E2, from 23.7 to 24.2 mg g(-1) for DCF and from 20.5 to 20.6 mg g(-1) for SMX. Removal efficiencies of 71%, 88% and 74% for DCF, SMX and E2, respectively, were obtained at breakthrough point when using mineral GAC, whereas for the vegetal GAC the figures were 76%, 77% and 65%, respectively. The carbon usage rate at the breakthrough point varied from 11.9 to 14.5 L g(-1) for mineral GAC and from 8.8 to 14.8 L g(-1) for vegetal GAC. Mineral CAG also exhibited the best performance when treating fortified natural water, since nearly complete removal was observed for all contaminants in the column operated for 22 h at a carbon usage rate of 2.9 L g(-1).

No abstract

RESUMO -Um dos maiores problemas no que diz respeito aos efluentes de indústrias têxteis é a presença de traços de corantes que não se aderem às fibras dos tecidos durante o tingimento. Além de serem prejudiciais ao meio ambiente devido à toxidade, os corantes impedem a passagem da luz solar nos leitos de água, reduzindo a atividade fotossintética dos ambientes contaminados. Técnicas tradicionais de tratamento promovem remoção incompleta do corante e requerem altos investimentos em equipamentos, reagentes e energia. A adsorção utilizando carvão ativado, apesar de eficiente, possui desvantagens financeiras, devido ao alto custo deste material adsorvente. Assim, há uma vasta procura por biomateriais, tais como as macrófitas, que são associadas à capacidade de purificação das águas onde estão presentes atuando como bioadsorventes de poluentes convencionais, metais pesados e compostos orgânicos. Estudou-se a utilização da macrófita aquática Salvinia cucullata como bioadsorvente para a remoção do corante sintético Ácido Laranja 7. Caracterizou-se a macrófita antes e após a bioadsorção por meio de espectroscopia no infravermelho, microscopia óptica e microscopia eletrônica de varredura, além de titração potenciométrica, análise termogravimétrica e calorimetria exploratória diferencial. Após o estudo, certificou-se que a biomassa constitui um promissor bioadsorvente para o tratamento de efluentes de indústrias têxteis.Palavras chave: efluentes, têxtil, bioadsorvente. INTRODUÇÃOBoa parte dos setores industriais (têxtil, papel, plástico, couro, alimentícia etc.) utilizam corantes e pigmentos em seus processos. O processo de tingimento no setor têxtil requer a utilização de grandes quantidades de água, corantes e produtos de diferentes composições (antiespumantes, dispersantes, eletrólitos, etc). Estima-se que sejam perdidos, durante a síntese e o processamento, aproximadamente 15% da produção total de corantes e pigmentos. Isto corresponde a uma descarga média diária de 128 toneladas para o meio ambiente (Zollinger, 2003). Cerca de 20% do total de

-Adsorption process is an efficient alternative in metal ions removal. Many materials can be used in this process; among them, we can cite biological materials such as aquatic macrophytes. The macrophytes have shown a high percentage of metal ions removal and they have an advantage of being low cost and have the possibility of growing. In view of this, the aim of this work is evaluate lead removal by Salvinia natans in dynamic system. Essays were carried out in a fixed bed column for different flow rates. The result showed the higher amount of lead removed from the column was 0.152 mmo.g -1 for a flow rate of 1 mL.min -1 and an initial concentration of lead of 1 mmol.L -1 . In order to know the changes in surface morphology of S. natans before and after the process as well as the functional groups that participate of the removal of lead, the characterization using the SEM/EDX and FTIR techniques was performed.

-Salvinia natansmacrophyte has been studied as a potential biosorbent for metal ions removal. We investigated in this work the performance of the macrophyte in recovery of lead and chromium from bicomponent synthetic solution from two different systems, batch and fixed bed. Equilibrium data were obtained by batch system through isotherms and fitted toLangmuir and Langmuir-Freundlich models.The breakthrough curves were performed at three different concentrations ratio. In order to know the biosorption mechanism FT-IR analyses were performed for S. natans before and after uptake of metal ions. The results showed different functional groups on the biomass surface and the ability of these groups bind with Cr +3 and Pb 2+ions in aqueous solution.

RESUMO -As técnicas tradicionais de remoção de metais de tóxicos de efluentes industriais são conhecidas por grande produção de lama química tóxica e por seu elevado custo. Buscam-se hoje novas tecnologias para efetuar este processo que contornem tais problemas. Neste trabalho investigou-se a viabilidade do uso da macrófita Salvinia Natans na remoção de Pb 2+ presente em efluente industrial. A macrófita foi caracterizada antes e após a remoção de Pb 2+ utilizando métodos convencionais para determinar condições de operação para o processo. Os resultados mostraram que a macrófita é um potencial bioadsorvente de metais tóxicos devido a sua resistência mecânica e capacidade de adsorção observada de 0,386 mmol de adsorbato por grama de adsorvente segundo o modelo de pseudo-segunda ordem.Palavras-chave -adsorção, metal tóxico, macrófita.