Removal of Pb²⁺ from aqueous system by live Oscillatoria laete-virens (Crouan and Crouan) Gomont isolated from industrial effluents.
Cyanobacteria have been found to be potential biosorbents of metal ions from waste water. The Pb²⁺ removal capacity of growing cells of indigenous cyanobacterium Oscillatoria laete-virens (Crouan and Crouan) Gomont was studied under batch experiments and it was found capable of removing Pb²⁺ of lower concentrations (below 100 mg L⁻¹). The effects of different concentrations of Pb²⁺, on the growth rate of alga were also evaluated. The research parameters include the pH of the solution, contact time, initial concentration of Pb²⁺, and culture density. Of the parameters studied, the pH of the solution was found to be the most crucial. The removal of Pb²⁺ peaked at an initial pH of 5. The data obtained from the equilibrium experiments were found well fitting with the Langmuir isotherm with a maximum sorptive capacity (q(max)) of 20.36 mg g⁻¹, indicating a good biosorbtive potential of growing cells. This was confirmed using scanning electron microscope and energy dispersive X-ray analysis, which showed the adsorption of lead on the surface of the cell. The species could tolerate a concentration as high as 60 mg L⁻¹ of Pb²⁺. It was observed that the removal obeyed the pseudo-second-order kinetics. The percentage removal was found to decrease with increasing metal concentration, from 10 to 100 mg L⁻¹. FTIR analysis indicates the involvement of amino, carboxylic and amide groups in the sorption process. Among the desorbing agents evaluated, an efficient recovery of 90.2 % was achieved by HCl, in 24 h. Thus Oscillatoria laete-virens (Crouan and Crouan) Gomont seems to be a promising metal biosorbent for the treatment of Pb²⁺, in waste waters.
Department of Applied Botany, Mangalore University, Mangalagangothri 574199, India. jyothi_ms2000@yahoo.co.in
Jyothi
J
Miranda
G
G
Krishnakumar
Avila
A
D'Silva
D000327:Adsorption; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000032:analysis*; D007477:Ions / Q000032:analysis / Q000378:metabolism; D007700:Kinetics; D007854:Lead / Q000302:isolation & purification*; D008855:Microscopy, Electron, Scanning / Q000379:methods; D054300:Oscillatoria / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D012996:Solutions; D013052:Spectrometry, X-Ray Emission / Q000379:methods; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D062065:Wastewater / Q000382:microbiology*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification
D007220:Industrial Waste; D007477:Ions; D007854:Lead; D012996:Solutions; D062065:Wastewater; D014874:Water Pollutants, Chemical