Biosorption of Uranium by Pseudomonas aeruginosa Strain CSU Immobilized in a Novel Matrix

Abstract

Pseudomonas aeruginosa CSU, a nongenetically engineered bacterial strain previously shown to bind dissolved hexavalent uranium (as UO 2 2+ and/or its cationic hydroxy complexes), shows promise as the basis of an immobilized-cell process for removal of dissolved uranium from contaminated wastewaters. A number of polymeric materials, including calcium alginate, polyacrylamide, polysulfone, and polyurethane, were evaluated as possible immobilization matrices for lyophilized biomass of P. aeruginosa CSU. Polyurethane-based materials such as hydrogel were identified as superior candidates for biomass immobilization. A novel polyurethane gel-bead fabrication technique was developed and successfully demonstrated at pilot-plant scale for producing mass quantities of spherical, uniform-size beads. The immobilized bacterial biomass was evaluated via the measurement of sorption isotherms and dynamics within a batch, stirred-tank reactor; and loading and elution behavior within a continuous, upflow, packed-bed columnar reactor. Sorption equilibrium and dynamics in a batch stirred tank were modeled with a pore-diffusion mass transfer model, by which a pore-diffusion coefficient was determined to be approximately 2.0 × 10 -6 cm 2 /s for uranyl ion transport through the polyurethane gel matrix. The biosorbent beads were regenerable with dilute (0.01-0.1 M) sodium carbonate solutions. Preliminary column breakthrough-elution studies indicated that P. aeruginosa CSU biomass immobilized within polyurethane gel beads was effective for removal of uranium from low-concentration, acidic wastewaters.

BIOSORPTION OF TEXTILE DYE USING IMMOBILIZED BACTERIAL (<i>PSEUDOMONAS AERUGINOSA<i/>) AND FUNGAL (<i>PHANEROCHATE CHRYSOSPORIUM<i/>) CELLS

“…Science Publications AJES biosorption (Hu and Reeves, 1997;Prakasham et al, 1999;Yan and Viraraghavan, 2001;Khoo and Ting, 2001;Beolchini et al, 2003;Bai and Abraham, 2003). Important immobilization matrices used in biosorbent immobilization include sodium alginate (Bai and Abraham, 2003;Xiangliang et al, 2005), polysulfone Beolchini et al, 2003), polyacrylamide (Bai and Abraham, 2003) and polyurethane (Hu and Reeves, 1997).…”

“…Important immobilization matrices used in biosorbent immobilization include sodium alginate (Bai and Abraham, 2003;Xiangliang et al, 2005), polysulfone Beolchini et al, 2003), polyacrylamide (Bai and Abraham, 2003) and polyurethane (Hu and Reeves, 1997). The choice of immobilization matrix is a key factor in the environmental application of immobilized biomass.…”

“…Among these, immobilization techniques such as entrapment and cross linking have been found to be practical for biosorption (Veglio and Beolchini, 1997;Volesky, 2001). Immobilization of microorganisms within a polymeric matrix has exhibited greater potential, especially in packed or fluidized bed reactors, with benefits including the control of particle size, regeneration and reuse of the biomass, easy separation of biomass and effluent, high biomass loading and minimal clogging under continuous-flow conditions (Hu and Reeves, 1997). Very few efforts have been made to utilize the immobilization concept for dye (Fu and Viraraghavan, 2003; …”

Kinetic Modeling of Methylene Blue and Crystal Violet Dyes Adsorption on Alginate-Fixed Water Hyacinth in Single and Binary Systems

“…However, they often suffer several drawbacks, and these include low biomass density, solid-liquid separation problems, possible biomass swelling, inability to regenerate/reuse and development of high pressure drop in the column mode [19]. To improve the mechanical properties of biosorbents, immobilization, which uses techniques such as entrapment and crosslinking, has been reported [20,21]. Immobilization of biosorbent material offers advantages including the control of particle size, regeneration and reuse of the biomass, easy separation of biomass and effluent, high biomass loading and minimal clogging under continuous-flow conditions [22][23][24][25][26].…”

“…Immobilization of biosorbent material offers advantages including the control of particle size, regeneration and reuse of the biomass, easy separation of biomass and effluent, high biomass loading and minimal clogging under continuous-flow conditions [22][23][24][25][26]. Common immobilization matrices used include sodium alginate, polysulphone, polyacrylamide, and polyurethane [21,[27][28][29].…”