title: U(VI) biosorption by bi-functionalized Pseudomonas putida @ chitosan bead: Modeling and optimization using RSM.
abstract: In this work, Pseudomonas putida cells immobilized into chitosan beads (PICB) were synthesized to investigate the impact of microorganism entrapment on biosorption capacity of prepared biosorbent for U(VI) biosorption from aqueous solutions. Response Surface Methodology (RSM) based on Central Composite Design (CCD) was utilized to evaluate the performance of the PICB in comparison with chitosan beads (CB) under batch mode. Performing experiments under optimal condition sets viz. pH 5, initial U(VI) concentration 500mg/L, biosorbent dosage 0.4g/L and 20wt.% bacterial cells showed that the observed biosorption capacity enhanced by 1.27 times from 398mg/g (CB) to 504mg/g (PICB) that confirmed the effectiveness of cells immobilization process. FTIR and potentiometric titration were then utilized to characterize the prepared biosorbents. While the dominant functional group in the binding process was NH3(+) (4.78meq/g) in the CB, the functional groups of NH3(+), NH2, OH, COOH (6.00meq/g) were responsible for the PICB. The equilibrium and kinetic studies revealed that the Langmuir isotherm model and the pseudo-second-order kinetic model were in better fitness with the CB and PICB experimental data. In conclusion, the present study indicated that the PICB could be a suitable biosorbent for uranium (VI) biosorption from aqueous solutions.
authors.affiliation: Nuclear Fuel Cycle Research School, Nuclear Science and Technology Research Institute, P.O. Box 11365/8486, Tehran, Iran.
authors.forename: Hozhabr
authors.initials: H
authors.lastname: Sohbatzadeh
authors.affiliation: Nuclear Fuel Cycle Research School, Nuclear Science and Technology Research Institute, P.O. Box 11365/8486, Tehran, Iran. Electronic address: akeshtkar@aeoi.org.ir.
authors.forename: Ali Reza
authors.initials: AR
authors.lastname: Keshtkar
authors.affiliation: Nuclear Fuel Cycle Research School, Nuclear Science and Technology Research Institute, P.O. Box 11365/8486, Tehran, Iran.
authors.forename: Jaber
authors.initials: J
authors.lastname: Safdari
authors.affiliation: Nuclear Fuel Cycle Research School, Nuclear Science and Technology Research Institute, P.O. Box 11365/8486, Tehran, Iran.
authors.forename: Faezeh
authors.initials: F
authors.lastname: Fatemi
mesh_terms: D001673:Biodegradation, Environmental; D048271:Chitosan / Q000737:chemistry; D002857:Chromium / Q000737:chemistry; D007700:Kinetics; D016958:Pseudomonas putida / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry; D013499:Surface Properties; D014501:Uranium / Q000737:chemistry; D014867:Water / Q000737:chemistry*; D018508:Water Purification
chemical_list: D012996:Solutions; D014867:Water; D002857:Chromium; D014501:Uranium; D048271:Chitosan
keywords: Potentiometric titration; Psudomonas putida @ chitosan; U(VI) biosorption