Biosorbents for heavy metals removal and their future

Application of biosorption for the removal of organic pollutants: a review

Plants vary considerably in their physiological response to selenium (Se). Some plant species growing on seleniferous soils are Se tolerant and accumulate very high concentrations of Se (Se accumulators), but most plants are Se nonaccumulators and are Se-sensitive. This review summarizes knowledge of the physiology and biochemistry of both types of plants, particularly with regard to Se uptake and transport, biochemical pathways of assimilation, volatilization and incorporation into proteins, and mechanisms of toxicity and tolerance. Molecular approaches are providing new insights into the role of sulfate transporters and sulfur assimilation enzymes in selenate uptake and metabolism, as well as the question of Se essentiality in plants. Recent advances in our understanding of the plant's ability to metabolize Se into volatile Se forms (phytovolatilization) are discussed, along with the application of phytoremediation for the cleanup of Se contaminated environments.

Selenium in higher plants.

Biosorption of heavy metals by Saccharomyces cerevisiae: a review.

Geomycology: biogeochemical transformations of rocks, minerals, metals and radionuclides by fungi, bioweathering and bioremediation

Binding of hard and soft metal ions to Rhizopus arrhizus biomass

Biomass from two fungi of the Mucorales order, laboratory cultured and immobilised Rhizopus arrhizus, and industrial waste Mucor miehei, was tested for capacity to adsorb copper from solution in batch and continuous-flow column systems. Maximum uptake levels were c 400 and 300 mmol g−1 (dry weight) respectively. Immobilisation of Rhizopus arrhizus in polyvinyl formal to cell loadings of 60% (w/w) did not diminish metal uptake levels. In continuous-flow columns both biosorbents adsorbed copper to levels equal or approaching the batch uptake values. Column breakthrough curves were fitted to a two parameter model and each of the parameters, σ and t0 , were linearly correlated with column operating parameters. Predicted breakthrough curves agreed closely with experimental values.



© 1999 Society of Chemical Industry

Continuous fixed bed biosorption of Cu2+ ions: application of a simple two parameter mathematical model

Volatilization of selenite in aqueous medium by a Penicillium species

Adsorption of metal ions by Rhizopus arrhizus biomass: Characterization studies

The dissolution of alginate gel beads in 20 g sodium citrate /l produces a linear decrease in bead diameter. The rate of dissolution is dependent on the concentration of CaCl2 within the gel beads. This method allows the controlled release of Saccharomyces cerevisiae from alginate gel beads and permits the simple and rapid determination of the radial distribution of cell concentration.

Joseph M. Brady

Papers

Binding of hard and soft metal ions to Rhizopus arrhizus biomass

Continuous fixed bed biosorption of Cu2+ ions: application of a simple two parameter mathematical model

Volatilization of selenite in aqueous medium by a Penicillium species

Adsorption of metal ions by Rhizopus arrhizus biomass: Characterization studies

Determination of the radial distribution of Saccharomyces cerevisiae immobilised in calcium alginate gel beads.