The performance of a continuous system for biosorption and desorption of zinc, cadmium, manganese and copper by the seaweed Sargassum sp.

F.P. Duta1, F.P. França1 and A.C.A. Costa2*

1 Universidade Federal do Rio de Janeiro, Departamento de Engenharia Bioquímica, Escola de Química, Centro de Tecnologia, Ilha do Fundão, Rio de Janeiro, Brasil.
2 Universidade do Estado do Rio de Janeiro, Departamento de Tecnologia de Processos Bioquímicos, Instituto de Química, R. S. Francisco Xavier 524, Pavilhão Haroldo Lisboa da Cunha, Maracanã, Rio de Janeiro, Brasil, 20550-013.

Received 31 December 2001; accepted 5 June 2002


The biosorption of cadmium, zinc, manganese and copper was carried out using brown seaweed Sargassum sp. in natura and regenerated with EDTA. The study was done in a continuous system consisting of four serial fixed-bed reactors filled up with a dry biomass of Sargassum sp. as adsorbing bed. The synthetic effluent consisted of a mixed solution containing the four metal ions, at 150 mg/L concentration, each one. It could be observed that the system was able to treat the mixed solution, in the preference order of Cu>Cd>Zn>Mn, both when in natura and regenerated biomass were used. Results also indicated that the amount of metals biosorbed by each column decreased, as a function of the pre-treatment performed by the previous reactor. The regenerated Sargassum sp. biomass presented a decreased biosorption capacity, due to partial desorption or destruction of adsorption sites on the surface of the seaweed. The system, as a whole, was able to treat a high amount of concentrated metals solution, generating outlet solutions able to be discharged according to Brazilian federal environmental legislation.

Keywords: Heavy metals; Biosorption; Sargassum; Desorption; Continuous system

* Corresponding author
   E-mail : acosta@uerj.br