Biosorbents for heavy metals removal and their future

Biosorption of heavy metals by Saccharomyces cerevisiae: a review.

Many algae have immense capability to sorb metals, and there is considerable potential for using them to treat wastewaters. Metal sorption involves binding on the cell surface and to intracellular ligands. The adsorbed metal is several times greater than intracellular metal. Carboxyl group is most important for metal binding. Concentration of metal and biomass in solution, pH, temperature, cations, anions and metabolic stage of the organism affect metal sorption. Algae can effectively remove metals from multi-metal solutions. Dead cells sorb more metal than live cells. Various pretreatments enhance metal sorption capacity of algae. CaCl2 pretreatment is the most suitable and economic method for activation of algal biomass. Algal periphyton has great potential for removing metals from wastewaters. An immobilized or granulated biomass-filled column can be used for several sorption/desorption cycles with unaltered or slightly decreased metal removal. Langmuir and Freundlich models, commonly used for fitting sorption data, cannot precisely describe metal sorption since they ignore the effect of pH, biomass concentration, etc. For commercial application of algal technology for metal removal from wastewaters, emphasis should be given to: (i) selection of strains with high metal sorption capacity, (ii) adequate understanding of sorption mechanisms, (iii) development of low-cost methods for cell immobilization, (iv) development of better models for predicting metal sorption, (v) genetic manipulation of algae for increased number of surface groups or over expression of metal binding proteins, and (vi) economic feasibility.

Use of Algae for Removing Heavy Metal Ions From Wastewater: Progress and Prospects

Nanometer titanium dioxide immobilized on silica gel as sorbent for preconcentration of metal ions prior to their determination by inductively coupled plasma atomic emission spectrometry.

Chromium is introduced into the environment by effluents in several industries. It is important to control this element since it is both toxic and carcinogenic. As its toxicity depends on its state of oxidation, it is especially interesting to determine its most abundant species, Cr(III) and Cr(VI). In this overview, we describe the requirements for chromium determination and speciation and review the analytical methods that have been used in these studies. Focusing in particular on developments since 2000, we examine the features of detection techniques, pre-treatments and applications of the various methods.

Chromium determination and speciation since 2000

Separation and speciation of Cr(III) and Cr(VI) with Saccharomyces cerevisiae immobilized on sepiolite and determination of both species in water by FAAS.

Determination of iron and nickel by flame atomic absorption spectrophotometry after preconcentration on Saccharomyces cerevisiae immobilized sepiolite.

Determination of Cu, Zn, Fe, Ni and Cd by flame atomic absorption spectrophotometry after preconcentration by Escherichia coli immobilized on sepiolite

By using the adsorbent Saccharomyces cerevisiae immobilized on sepiolite an adsorption-elution method was developed for the preconcentration of Cu, Zn, and Cd followed by flame atomic absorption spectrometry (FAAS). Recoveries were 98.3 ± 0.4% for Cu, 94.2 ± 0.3% for Zn, and 99.04 ± 0.04% for Cd at 95% confidence level obtained by the column method. The influence of sea water matrix elements on the separation of the trace elements was also assessed by using the column procedure. The breakthrough capacities were found to be 74 μmol/g for copper, 128 μmol/g for zinc and 97 μmol/g for cadmium. After optimization the proposed method was applied to the trace metal determination in sea and river water.

Determination of Cu, Zn and Cd in water by FAAS after preconcentration by baker's yeast (Saccharomyces cerevisiae) immobilized on sepiolite

https://www.jstage.jst.go.jp/article/analsci/17/7/17_7_901/_pdf

Determination of Fe(II) and Fe(III) in Water by Flame Atomic Absorption Spectrophotometry after Their Separation with Aspergillus niger Immobilized on Sepiolite

Mustafa Lale

Papers

Separation and speciation of Cr(III) and Cr(VI) with Saccharomyces cerevisiae immobilized on sepiolite and determination of both species in water by FAAS.

Determination of iron and nickel by flame atomic absorption spectrophotometry after preconcentration on Saccharomyces cerevisiae immobilized sepiolite.

Determination of Cu, Zn, Fe, Ni and Cd by flame atomic absorption spectrophotometry after preconcentration by Escherichia coli immobilized on sepiolite

Determination of Cu, Zn and Cd in water by FAAS after preconcentration by baker's yeast (Saccharomyces cerevisiae) immobilized on sepiolite

Determination of Fe(II) and Fe(III) in Water by Flame Atomic Absorption Spectrophotometry after Their Separation with Aspergillus niger Immobilized on Sepiolite