Metal adsorption and desorption by lyophilized Pseudomonas aeruginosa

Biosorptive capacity of Cd(II) and Cu(II) by lyophilized cells of Pseudomonas stutzeri

“…The data obtained from this experiment was further used successfully to evaluate the kinetics of the adsorption process. This short time required for biosorption is in accordance with the result given by other authors (Sar et al, 1999;Volesky, 1990;Zouboulis et al, 2004). Gabr et al (2008) showed that the maximum biosorption of lead and nickel was reached after 30 min.…”

“…However, at higher concentrations metals need to diffuse into the biomass surface by intra particular diffusion and greatly hydrolyzed ions will diffuse at a slower rate (Gabr et al, 2008). The overall observations from both Freundlich and Langmuir isotherms for metal biosorption were in agreement with many previous studies (Acosta et al, 2005;Pardo et al, 2003;Sar et al, 1999). The selectivity order for metal ion towards the studied biomass matrices is Cd Cu for a given initial metal ion concentration.…”

“…The rate constants (k) for Cd(II) over the range of initial concentrations were higher than those for Cu(II). The patterns were observed in line within 50 min, indicating a correlation with the characteristics of inert biomass and its physicochemical interactions with the metal ion (Kim et al, 1996;Sar et al, 1999). The rapid metal sorption is also highly desirable for successful deployment of the biosorbents for practical applications (Sar et al, 1999;Volesky, 1990).…”

“…As the pH increased, more ligands such as carboxyl, phosphate, imidazole and amino groups would be exposed and carried negative charges with subsequent attraction of metallic ions with positive charge and biosorption onto the cell surface (Pardo et al, 2003). Previous research has shown that most living microorganisms have a limited absorption for heavy metals at lower pH, due to physiological properties (Fowle and Fein, 1999;Sar et al, 1999) as well as physical adsorbents such as zeolites steeply decreasing their adsorption capacity for both Cu and Cd with a decrease in pH (Ok et al, 2007).…”

OPTIMIZATION OF Cr AND Cu BIOSORPTION BY GREEN MARINE ALGAE Caulerpa racemosaVar. Cylindracea & Ulva lactuca

“…The reaction continues till the equilibrium is developed between the adsorbent bound sorbate groups and the amount left in a solution [14]. Further metal sorption mechanisms using biosorbent occurs via chelation, ion-exchange, micro-precipitation, co-ordination, complexation etc [15]. The potential of seaweeds as biosorbents for removal of heavy metal has been studied by various scientists in recent years offers continuous availability and reusability of sorbent in numerous cycles.…”