Biosorption Of Uranium Research Articles

Biosorption of uranium by immobilized cells of Rhodotorula glutinis

Biosorption of uranium ions from diluted solution (≤40 mg L−1) onto immobilized cells of Rhodotorula glutinis was investigated in a batch system. Equilibrium, kinetic and thermodynamic studies were conducted by considering the effect of initial uranium concentration, contact time and temperature. Non-linear forms of Langmuir, Freundlich and Sips isotherm models were used to fit the equilibrium data, Sips model was designated as the best one. Kinetic data were simulated by non-linear pseudo-first-order, pseudo-second-order and intra-particle diffusion equations. Pseudo-first-order kinetic equation described the experimental data better than pseudo-second-order equation and intra-particle diffusion equation can fit the kinetic data with two independent curves. Thermodynamic parameters, including ∆H 0, ∆G 0 and ∆S 0, were evaluated, the sorption process was determined to be spontaneous and endothermic. Uranium sorption from pure uranium solutions and uranium pit wastewater by immobilized biomass and blank beads, as well as the regeneration results indicated that immobilized R. glutinis can be use to recovery uranium from uranium pit wastewater.

Research on Biological Materials with Uranium Biosorption by Microalgae: A Review

With the development of nuclear science, uranium-contained wastewater was heavily generated. If not properly handled, it is bound to bring environmental and human health hazards. Conventional uranium-contained wastewater treatment technologies are limited in certain aspects, such as high reagent and energy consumption, secondary pollution and so on. The microalgae-based biosorption technique for treating uranium-contained wastewater is an economical, simple, effective and feasible approach. This paper summarized the basic mechanism of the technology, and discussed the effects of different pH, algal cell biomass concentration, initial uranium ion concentration and the growth state of algal cells on the biological treatment process of uranium-contained wastewater. Finally, the study explored the future prospects of the technology.

Toxicity of ionic liquids to Clostridium sp. and effects on uranium biosorption

As green solvents ionic liquids (ILs) show high potential in nuclear industry for extraction and purification of actinides. However, to date relatively little information has been gained on ILs application in microbial processes, for example biosorption of radionuclides. We investigated the effects of three ILs, 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6), N-ethylpyridinium trifluoroacetate (EtPyCF3COO) and N-ethylpyridinium tetrafluoroborate (EtPyBF4) on the growth and biosorption of uranium by Clostridium sp. The ILs affected the growth of the bacterium as evidenced by decreases in optical density, total gas production, and organic acids production from glucose metabolism. The IC50-48h of three ILs decreased in the order of BMIMPF6 (8.26mM)>EtPyBF4 (7.04mM)>EtPyCF3COO (4.05mM). Uranium biosorption by the bacterial cells decreased by 75% in the presence of 1% (v/v) BMIMPF6 and by about 90% with 1% (v/v) EtPyBF4 or EtPyCF3COO, in comparison to the control without ILs. The diminished biosorption may be attributed to the membrane damages induced by EtPyBF4 and EtPyCF3COO, which can be visualized by Transmission Electron Microscope (TEM) analysis. Energy-dispersive X-ray spectroscopy (EDS) analysis revealed the accumulation of uranium inside peripheral membrane of the cells exposed to uranium alone or with BMIMPF6, while little or no accumulation was observed in the presence of EtPyBF4 and EtPyCF3COO. These results imply that potential toxicity of ILs towards microorganisms is a particularly important issue in limiting its biotechnological applications.

Biosorption of Uranium from Aqueous Solution by Live and Dead Aspergillus niger

AbstractThe ability of live and dead biomass of indigenous Aspergillus niger was examined for the removal of uranium (VI) from dilute aqueous solutions. The influences of different experimental parameters such as initial solution pH, initial uranium concentration, biomass concentration, and contact time were investigated. The results indicated that the maximum sorption of biomass was observed at pH 5 and pH 4, and biosorption equilibrium was established in 120 and 60 min, for live and dead biomass, respectively. Optimal biosorption was observed at concentrations of 0.2 and 0.3 g dry biomass per 100 mL for live and dead biomass, respectively. Langmuir and Freundlich models were well able to explain the sorption-equilibrium data with satisfactory correlation coefficients higher than 0.9 for both sorbents. Moreover, the Langmuir isotherm in linear form fit better for both live and dead biomass of A. niger. The kinetic study showed that the pseudosecond-order model was appropriate to describe the sorption pro...

Enhancement of uranium(VI) biosorption by chemically modified marine-derived mangrove endophytic fungus Fusarium sp. #ZZF51

Fusarium sp. #ZZF51, mangrove endophytic fungus originated from South China Sea coast, was chemically modified by formaldehyde, methanol and acetic acid to enhance its affinity of uranium(VI) from waste water. The influencing factors about uranium(VI) adsorption such as contact time, solution pH, the ratio of solid/liquid (S/L) and initial uranium(VI) concentration were investigated, and the suitable adsorption isotherm and kinetic models were determined. In addition, the biosorption mechanism was also discussed by FTIR analysis. Experimental results show that the maximum biosorption capacity of formaldehyde-treated biomass for uranium(VI) at the optimized condition of pH 6.0, S/L 0.6 and equilibrium time 90 min is 318.04 mg g−1, and those of methanol-treated and HAc-treated biomass are 311.95 and 351.67 mg g−1 at the same pH and S/L values but different equilibrium time of 60 and 90 min, respectively. Thus the maximum biosorption capacity of the three kind of modified biomass have greatly surpassed that of the raw biomass (21.42 mg g−1). The study of kinetic exhibits a high level of compliance with the Lagergren’s pseudo-second-order kinetic models. Langumir and Freundlich models have proved to be well able to explain the sorption equilibrium with the satisfactory correlation coefficients higher than 0.96. FTIR analysis reveals that the carboxyl, amino and hydroxyl groups on the cell wall of Fusarium sp. #ZZF51 play an important role in uranium(VI) biosorption process.

Biosorption of uranium by Bacillus sp.FB12 isolated from the vicinity of a power plant

Biosorption represents a technological innovation as well as a cost effective excellent remediation technology for cleaning up radionuclides from aqueous environment. In the present study, a bacteria strain FB12 with high adsorption rate of uranium ion was isolated from the vicinity of the nuclear power plant. It was tentatively identified as Bacillus sp.FB12 according to the 16S rDNA sequencing. Efforts were made to further improve the adsorption rate and genetic stability by UV irradiation and UV-LiCl cooperative mutagenesis. The improved strain named Bacillus sp.UV32 obtains excellent genetic stability and a high adsorption rate of 95.9%. The adsorption of uranium U (VI) by Bacillus sp.UV32 from aqueous solution was examined as a function of metal ion concentration, cell concentration, adsorption time, pH, temperature, and the presence of some foreign ions. The adsorption process of U (VI) was found to follow the pseudo-second-order kinetic equation. The adsorption isotherm study indicated that it preferably followed the Langmuir adsorption isotherm. The thermodynamic parameters values calculated clearly indicated that the adsorption process was feasible, spontaneous and endothermic in nature. These properties show that Bacillus sp.UV32 has potential application in the removal of uranium (VI) from the radioactive wastewater.

Equilibrium, kinetic and thermodynamic studies of uranium biosorption by calcium alginate beads

Calcium alginate beads are potential biosorbent for radionuclides removal as they contain carboxyl groups. However, until now limited information is available concerning the uptake behavior of uranium by this polymer gel, especially when sorption equilibrium, kinetics and thermodynamics are concerned. In present work, batch experiments were carried out to study the equilibrium, kinetics and thermodynamics of uranium sorption by calcium alginate beads. The effects of initial solution pH, sorbent amount, initial uranium concentration and temperature on uranium sorption were also investigated. The determined optimal conditions were: initial solution pH of 3.0, added sorbent amount of 40 mg, and uranium sorption capacity increased with increasing initial uranium concentration and temperature. Equilibrium data obtained under different temperatures were fitted better with Langmuir model than Freundlich model, uranium sorption was dominated by a monolayer way. The kinetic data can be well depicted by the pseudo-second-order kinetic model. The activation energy derived from Arrhenius equation was 30.0 kJ/mol and the sorption process had a chemical nature. Thermodynamic constants such as ΔH0, ΔS0 and ΔG0 were also evaluated, results of thermodynamic study showed that the sorption process was endothermic and spontaneous.

Biosorption of uranium by melanin: Kinetic, equilibrium and thermodynamic studies

Limitation of conventional techniques for the removal of heavy metals present at low concentrations, has led to the need for developing alternate technologies like biosorption. In the present study we describe the use of melanin pigment synthesized through green technology, for sorption of uranium from aqueous system. Biosynthesized melanin showed good uptake over a broad pH range. Removal of uranium was rapid and equilibrium was reached within 2h of contact. It was observed that the kinetic data fits well into Lagergren's pseudo-second order equation. A maximum loading capacity of 588.24 mg g(-1) was calculated from Langmuir plot. Thermodynamic studies performed revealed that sorption process was favorable. Binding of uranium on the surface of melanin was confirmed by FT-IR and energy dispersive spectroscopy (EDS). Thus, biosynthesized melanin can be efficiently used as a sorbent for removal of uranium from aqueous solution.

The Uranium Biosorption by Chlorella Pyrenoidosa and its Physiological Responses to Uranium

The effect of uranium at various concentration on the growth of Chlorella pyrenoidosa and the resistance of Chlorella pyrenoidosa to uranium were investigated in this paper. The results showed that the content of O2- and the activity of CAT arose when the concentration of uranium varied at the range of 0.1 to 1.0 mg/L. Uranium had no negative effect on the growth of Chlorella pyrenoidosa at the concentration of 0.1 to 0.5 mg/L, however, had positive effect to some extent. And the rise of the content of O2- and the activity of CAT was followed by rapidly returning to the normal level. The uranium at the concentration of 1.0 mg/L prolonged the lag period of the growth of Chlorella pyrenoidosa. The growth of Chlorella pyrenoidosa arose negatively, the content of O2- also arose to an unreturnable level and the activity of CAT was lower than CK when the concentration of uraniumm varied at the range of 5.0 to 10.0 mg/L. The uranium biosorption rate by Chlorella pyrenoidosa reached to the highest value of 70.43%when concentration of uraniumm was 0.5 mg/L. Chlorella pyrenoidosa is resistant to uranium of low concentration（≤1.0mg/L）and its biosorption rate is rather high, which indicated good prospect in its future application.

Biosorption of uranium by magnetically modified Rhodotorula glutinis

Adsorption of uranium from aqueous solution onto the magnetically modified yeast cell, Rhodotorula glutinis, was investigated in a batch system. Factors influencing sorption such as initial solution pH, biomass dosage, contact time, temperature, initial uranium concentration and other common cations were analyzed. Sorption isotherm, kinetic and thermodynamic studies of uranium on magnetically modified R. glutinis were also carried out. The temperature dependent equilibrium data agreed well with the Langmuir model. Kinetic data obtained at different temperatures were simulated using pseudo-first-order and pseudo-second-order kinetic models, the pseudo-second-order kinetic model was found to describe the data better with correlation coefficients near 1.0. The thermodynamic parameters, ΔH°, ΔS° and ΔG° were calculated from the sorption data gained at different temperatures. These thermodynamic parameters showed that the sorption process was endothermic and spontaneous. All results indicated that magnetically modified R. glutinis can be a potential sorbent for uranium wastewater treatment.

The effects of aqueous bicarbonate and calcium ions on uranium biosorption by Arthrobacter G975 strain

Uranium (VI) biosorption was investigated using carbonate-free and carbonate amended synthetic groundwater (SGW) under conditions relevant to Ca-rich carbonate-bearing subsurface environments. SGW was amended with bicarbonate concentrations ranging between 0.5 and 5mM and a G975 Arthrobacter oxydans strain, a soil bacterium previously isolated from Hanford Site soil. Selected treatments were amended with 5mM of calcium to evaluate its effect on U(VI) biosorption. The study confirmed that Arthrobacter sp. G975 can effectively remove soluble U(VI) ions from aqueous solution. The Langmuir, Linear, and Freundlich isotherms were fitted to the experimental data. Based on a higher correlation coefficient, the data was better fit by the Langmuir model. The presence of calcium and bicarbonate ions in SGW affects the sorption behavior of U(VI) due to the formation of highly soluble and stable uranyl-carbonate and calcium uranyl carbonate complexes that reduce adsorption of U(VI). Increasing aqueous bicarbonate concentrations exponentially reduced the U(VI) microbial adsorption compared to values obtained in carbonate-free solutions. The differences in U(VI) uptake generated by calcium additions in bicarbonate-free solutions were small enough to conclude that calcium was not a governing factor in biosorption. Results suggest that in the presence of bicarbonate and calcium, the damage to bacterial cells caused by U(VI) toxicity was reduced, yielding similar values for TOC degradation and cell density compared to U(VI)-free controls.

Characterization and properties of Pleurotus mutilus fungal biomass as adsorbent of the removal of uranium(VI) from uranium leachate

Removal and recovery of uranium from dilute aqueous solutions by dead fungal biomass (Pleurotus mutilus) have been studied by biosorption. The parameters that affect the uranium(VI) adsorption, such as: pH solution, temperature, biomass particle size and speed of stirring have been investigated and optimized. The experimental data were analyzed using pseudo-first-order and pseudo-second-order equations. The Freundlich and Langmuir adsorption models have been used for the mathematical description of the adsorption equilibrium. The maximum uranium biosorption capacity has been calculated. The value obtained (636.9 mg g−1) showed that P. mutilus is a good adsorbent. Also, the chemical bands involved in uranium link have been identified. We have applied this biosorption to actual waste uranium leachate, the results are satisfactory and promising.

Biosorption of Uranium by <i>Deinococcus radiodurans</i> Cells under Culture Conditions

The biosorption of uranium by Deinococcus radiodurans cells under culture conditions was studied in this research. The growth curve showed that uranium did not markedly inhibit the growth of Deinococcus radiodurans cells in short culture time. The biosorption results showed that the Deinococcus radiodurans cells had high biosorption capability for uranium under culture conditions with max biosorption efficiency of 86%, and max biosorption quantity of 230 mg g-1. The results indicated that Deinococcus radiodurans can be used as the good radioactive wastewater decontamination biosorbent under culture conditions

Removal and recovery of uranium (VI) from aqueous solutions by immobilized Aspergillus niger powder beads

The immobilized Aspergillus niger powder beads were obtained by entrapping nonviable A. niger powder into Ca-alginate gel. The effects of pH, contact time, initial uranium (VI) concentration and biomass dosage on the biosorption of uranium (VI) onto the beads from aqueous solutions were investigated in a batch system. Biosorption equilibrium data were agreeable with Langmuir isotherm model and the maximum biosorption capacity of the beads for uranium (VI) was estimated to be 649.4 mg/g at 30 °C. The biosorption kinetics followed the pseudo-second-order model and intraparticle diffusion equation. The variations in enthalpy (26.45 kJ/mol), entropy (0.167 kJ/mol K) and Gibbs free energy were calculated from the experimental data. SEM and EDS analysis indicated that the beads have strong adsorption capability for uranium (VI). The adsorbed uranium (VI) on the beads could be released with HNO(3) or HCl. The results showed that the immobilized A. niger powder beads had great potential for removing and recovering uranium (VI) from aqueous solutions.

Efficient uranium(VI) biosorption on grapefruit peel: kinetic study and thermodynamic parameters

The uranium(VI) biosorption by grapefruit peel was studied from aqueous solutions. Batch experiments was conducted to evaluate the effect of contact time, initial uranium(VI) concentration, initial pH, adsorbent dose, salt concentration and temperature. The equilibrium process was well described by the Langmuir, Redlich–Peterson and Koble–Corrigan isotherm models, with maximum sorption capacity of 140.79 mg g−1 at 298 K. The pseudo second order model and Elovish model adequately describe the kinetic data in comparison to the pseudo first order model and the process involving rate-controlling step is much complex involving both boundary layer and intra-particle diffusion processes. The effective diffusion parameter Di and Df values were estimated at different initial concentration and the average values were determined to be 1.167 × 10−7 and 4.078 × 10−8 cm2 s−1. Thermodynamic parameters showed that the biosorption of uranium(VI) onto grapefruit peel biomass was feasible, spontaneous and endothermic under studied conditions. The physical and chemical properties of the adsorbent were determined by SEM, TG-DSC, XRD and elemental analysis and the nature of biomass–uranium (VI) interactions was evaluated by FTIR analysis, which showed the participation of COOH, OH and NH2 groups in the biosorption process. Adsorbents could be regenerated using 0.05 mol L−1 HCl solution at least three cycles, with up to 80% recovery. Thus, the biomass used in this work proved to be effective materials for the treatment of uranium (VI) bearing aqueous solutions.

Biosorption of uranium(VI) by a mangrove endophytic fungus Fusarium sp. #ZZF51 from the South China Sea.

The uranium(VI) accumulation was studied in detail by using the biomass of mangrove endophytic fungus Fusarium sp.#ZZF51 from the South China Sea. The uranium(VI) biosorption process onto the tested fungus powders was optimized at pH 4.0, adsorption time 60 min, and uranium(VI) initial concentration 50 mg L−1 with 61.89% of removal efficiency. According to Fourier transform infrared spectra for the tested fungus before and after loaded with uranium(VI), the results showed that both of hydroxyl and carboxyl groups acted as the important roles in the adsorption process. In addition, the experimental data were analyzed by using parameter and kinetic models, and it was obtained that the Langmuir isotherm model and the pseudo-second-order kinetic model provided better correlation with the experimental data for adsorption of uranium(VI).

Bark, a suitable biosorbent for the removal of uranium from wastewater – From laboratory to industry

This paper shows that natural materials such as barks can successfully replace synthetic resins for industrial purposes. Evaluated in batch conditions, biosorption of uranium on suitably prepared Douglas fir barks took place in less than 10 min and appeared to be optimum at pH>4. The biosorption process of uranium (uranyl form UO) was characterized in the optimal physico-chemical conditions and could be mathematically modeled as a Langmuir isotherm. With a maximum uranium specific uptake q max value of 1.16 meq.g-1 (138 mgU.g-1 ) it was found that the sorption capability of Douglas fir barks was at least five times higher for uranium than for other heavy metals such as lead. Adsorption of uranium contained in water leached from a former uranium mine was then monitored over a one-month period in a laboratory-scale chromatography column. The fixation capacity remained fairly constant throughout the whole testing period. Water radioactivity decreased from 1500 mBq.L-1 (0.12 mgU.L-1 ) to (0.4 μ gU.L-1 ) at the column exit. This technology was successfully transferred and tested through a pilot project under industrial conditions with the support of AREVA NC.

Binary biosorption of uranium(VI) and nickel(II) from aqueous solution by Ca-pretreated Cystoseira indica in a fixed-bed column

Simultaneous biosorption of uranium(VI) and nickel(II) ions onto Ca-pretreated Cystoseira indica biomass was studied and compared with single uranium or nickel biosorption in a fixed-bed column. Results of single biosorption showed the breakthrough and exhaustion time increase with the increase of the flow rate and inlet metal concentration for both metal ions. Also, it was observed that there was an optimum flow rate of 1.4 mL min−1 (surface loading of 0.792 cm min−1) for both metal ions in the column. Results from both single and binary systems showed the adsorption capacity of C. indica for both metal ions increases with the increasing inlet concentration of each component and C. indica had a stronger affinity for uranium than nickel ions. The binary system results showed that the presence of the second component affected the adsorption of the first one by C. indica so the antagonistic action was observed. Also, the inhibitory effect of uranium ions on the nickel adsorption was greater than nickel ions on the uranium adsorption. The uranium and nickel breakthrough curves under different conditions were described by the Thomas, Yoon-Nelson and Yan models. Among these models, the Yan model appeared to describe the experimental results better.

Biosorption of uranium(VI) by bi-functionalized low cost biocomposite adsorbent

This paper presents biosorption properties of U(VI) by bi-functionalized biocomposite adsorbent consists of macro marine algae ( Jania rubens) and yeast ( Saccharomyces cerevisiae) immobilized on silica gel. Removal of U(VI) from aqueous solution by biosorption on biocomposite in a single component system with pH, initial concentration of U(VI), various contact time and temperature was investigated. Experimental equilibrium biosorption data was analyzed by five two-parameter equations, namely; Langmuir, Freundlich, Dubinin–Radushkevich (D–R), Temkin and Flory–Huggins isotherms. Among these isotherm models, the Temkin model fits better with the experimental data compared to others. Thermodynamic parameters, such as the enthalpy (ΔH°), entropy (ΔS°) and Gibbs free energy (ΔG°) were calculated from the slope and intercept of logK d vs. 1/T plot. Results suggested that the bi-functionalized low cost biocomposite adsorbent is a suitable biosorbent material to remove uranium ions from diluted aqueous solutions. On the other hand, immobilization of algae and yeast on silica gel was found to improve their interaction properties with uranium ions in biosorption process.

Uranium biosorption by Padina sp. algae biomass: kinetics and thermodynamics.

Kinetic, thermodynamic, and equilibrium isotherms of the biosorption of uranium ions onto Padina sp., a brown algae biomass, in a batch system have been studied. The kinetic data were found to follow the pseudo-second-order model. Intraparticle diffusion is not the sole rate-controlling factor. The equilibrium experimental results were analyzed in terms of Langmuir isotherm depending with temperature. Equilibrium data fitted very well to the Langmuir model. The maximum uptakes estimated by using the Langmuir model were 434.8, 416.7, 400.0, and 370.4 mg/g at 10°C, 20°C, 30°C, and 40°C, respectively. Gibbs free energy was spontaneous for all interactions, and the adsorption process exhibited exothermic enthalpy values. Padina sp. algae were shown to be a favorable biosorbent for uranium removal from aqueous solutions.