Lead Sorption from Aqueous Solutions by Pseudomonas putida (p168) and its Composites with Palygorskite and Sepiolite Clays

آب و خاک

Article 3, Volume 30, Issue 2 - Serial Number 46, May 2016, Pages 594-604   

Document Type: Research Article

DOI: 10.22067/jsw.v30i2.44210

Authors

Marzieh tavanaei¹; somayeh bakhtiari²; mehran shirvani^{* 1}

¹Isfahan University of Technology

²Sirjan University of Technology

Abstract

Introduction: Heavy metals contamination due to natural and anthropogenic sources is a global environmental concern. Lead (Pb) is one of the very toxic heavy metals. Industrial production processes and their emissions, mining operation, smelting, combustion sources and solid waste incinerators are the primary sources of lead. This heavy metal has aberrant effects on the environment and living organisms. Hence, proper treatment of lead from soil and industrial wastewaters is very important. In order to remove toxic heavy metals from contaminated water systems, conventional methods such as chemical precipitation, coagulation, ion exchange, solvent extraction and filtration, evaporation and membrane methods are being used. These conventional methods generally have high costs and technical problems. Therefore, biosorption processes, in which microorganisms are used as sorbents, have been considered as economical and environmentally friendly options for removal of heavy metals from aqueous solution. Clay minerals are another group of sorbents used in removal of heavy metals from polluted environments. Furthermore, bacterial cells can be attached on clay mineral surfaces and form bacteria-mineral composites. These composites adsorb heavy metals and convert them into forms with low mobility and bioavailability. Pseudomonas putida is a unique microorganism with a high tendency to sorb and/or degrade certain environmental pollutants. Palygorskite and sepiolite are the fibrous clay minerals of arid and semiarid regions; their structures consist of ribbons and channels. These fibrous minerals have various applications in industry and the environment because of its large surface area and high adsorption capacity. The present study was conducted in order to determine the ability of Pseudomonas putida (P168), and its composites with palygorskite and sepiolite in lead sorption.
Materials and Methods: The bacterial strain used in the present study was Pseudomonas putida (P168) grown and maintained on Nutrient Broth (NB). The population of living and non-viable bacteria in suspension was determined by an optical microscope. The minerals used in this study were palygorskite from Florida (the Source Clay Minerals Repository, Purdue University, IN) and sepiolite from Yazd (Iran). The clay samples were ground and passed through 0.05 mm (mesh #270) sieve. The clays were then saturated with calcium chloride (0.5 M) and washed free of salts. Batch experiments were performed to measure Pb sorption by Pseudomonas putida. For this purpose, 10-ml aliquots of bacterial suspension (7.24×107 cells ml-1) were added to10 ml solutions containing Pb with concentration ranged from15-110 mg L-1. The mixtures were gently shaken at 30 ◦C for 24 h and centrifuged at 3000 rpm for 20 min. The concentration of Pb in the supernatants was finally measured by atomic absorption spectrometer. The percentage of sorbed Pb was determined by subtracting the amount of unabsorbed Pb from that initially added. Various hybrids of P. putida and clays were also exposed to solution of 0.5 mM Pb in 0.01 M KNO3 to determine the role of composites in sorption of Pb. Langmuir and Freundlich adsorption isotherms were chosen to describe the biosorption equilibrium data. GraphPad Prism 5.0 was used for determining the isothermal parameters using non-linear regression analysis. Data were analyzed with the Statistical Analysis System (SAS). Experimental design was factorial in form of complete randomized block.
Results and Discussion: Pseudomonas putida showed a considerable capacity to sorb Pb ions. Lead sorption isotherms were sufficiently fitted with the Langmuir and Freundlich models. The Pb sorption isotherms by P. putida were L-type showing a high affinity of P. putida for Pb ions. Lead sorption capacity (qmax) of P. putida was estimated to be 582.4 mg g-1 and its Langmuir constant (KL) was found to be 0.11 mg L-1. The experimental data of lead sorption (7.5-55.5 mg L-1 initial concentration) by P.putida (P168) demonstrated that about 31.5% to 78.4% of the intial concentration of Pb was taken up by these bacteria. Sorption of Pb decreased with the increase of bacteria in the bacteria-clay composites, which may be due to the occupation of adsorption sites on the clay surface by the bacteria. Composites of bacteria-sepiolite were more effective than bacteria-palygorskite in Pb sorption due to the larger channel dimensions, greater surface area, and more functional groups of sepiolite than palygorskite. LSD test showed that there were significant differences between the hybrid sorbents with different ratios and single bacterial cells in Pb sorption.
Conclusion: The results showed that P. putida and its composites with palygorskite and sepiolite clays exhibited a high potential for the removal of Pb from aqueous solutions.

Keywords

adsorption isotherm; Biosorption; Fibrus Clays; Heavy metals

References

1- Bremner J.M., and Mulvaney C.S. 1982. Methods of soil analysis. Page, A.L., Miller, R.H. and Keeney, D.R. (ed.), Chemical and microbiological properties, American Society of Agronomy, Soil Science Society of America, Madison, WI.

2- Chen X., Hu S., Shen C., Dou C., Shi J., and Chen Y. 2009. Interaction of Pseudomonas putida CZ1 with clays and ability of the composite to immobilize copper and zinc from solution. Bioresource Technology, 100: 330-337.

3- Chen X.C., Wang, Y.P., Qi Lin J.Y.S., Wu W.X., and Chen Y.X. 2005. Biosorption of copper (II) and zinc(II) from aqueous solution by Pseudomonas putida CZ1. Colloids and Surfaces B-Biointerfaces, 46: 101–107.

4- Colak F., Atarb N., Yazıcıoglu D., and Olgun A. 2011. Biosorption of lead from aqueous solutions by Bacillus strains possessing heavy-metal resistance. Chemical Engineering Journal, 173: 422- 428.

5- Dapaah S.Y., and Hill G.A. 1992. Biodegradation of chlorophenol mixtures by Pseudomonas putida. Biotechnology and Bioengineering, 40: 1353-1358

6- Fooladifar R., Kamani H., and Khaefi M. 2003. Removal of heavy metals from aqueous solutions by biosorption. 3417-3425. 9th National Congress of Chemical Engineering. 23-25 Nov. 2003. University of Science and Technology Tehran, Iran. (in Persian)

7- Gadd G. M. 1992. Encyclopedia of Microbiology (ed. Lederberg. J.) Academic Press Inc. Harcourt Brace Javanovich Publishers., San Diego, 2: 351-360

8- Giles C. H., Smith D., and Huitson A. 1974. A general treatment and classification of the solout adsorption isotherm. Journal of Colloid and Interface Science, 47: 755-765.

9- Kalkan E., Nadaroglu H., Dikbas N., Tasgin E., and Celebi N. 2013. Bacteria-Modified Red Mud for adsorption of cadmium ions from aqueous soloutions. Polish Journal of Environmental Studies, 22: 417-429.

10- Langmuir I. 1918. The adsorption of gases on plane surface of glass, mica, and platinum. Journal of the American Chemical Society, 40: 1361-1382.

11- Lopez A., Lazaro N., and JM M. A. P. 2000. Effect of pH on the adsorption of nickel and other heavy metals by Pseudomonas fluorescens 4F39. Journal of Industrial Microbiology & Biotechnology, 24: 146-151.

12- Low M. J. D. 1960. Kineics of cheisorption of gases on solid. ChemicalL Reviews, 60: 267-312.

13- Marandi A., and Amyrafshar H. 2008. Biosorption of Pb (II) and Zn (II) by non-living biomass of Phanerochaete chrysosporium. Environmental Science and Technology, 10: 197-207. (in Persian)

14- Moon E. M., and Peacock C. L. 2012. Adsorption of Cu(II) to ferrihydrite and ferrihydrite–bacteria composites: Importance of the carboxyl group for Cu mobility in natural environments. Geochimica ET Cosmochimica Acta, 92: 203-219.

15- Rong X., Huang Q., Xiaomin H., Chen H., Cai P., and Liang w. 2008. Interaction of Pseudomonas putida with kaolinite and montmorillonite. A combination study by equilibrium adsorption, ITC, SEM and FTIR. 64: 49–55.

16- Shirvani M., Shariatmadari H., and Kalbasi M. 2007. Kinetics of cadmium desorption from fibrous silicate clay minerals: Influence of organic ligands and aging. Applied Clay Science, 37: 175-184.

17- Singh S., Ma P. L. Q., and Hendry M. J. 2006. Characterization of aqueous lead removal by phosphatic clay: Equilibrium and kinetic studies. Journal of Hazardous Materials, 136: 654-662.

18- Sparks D. L. 2003. Environmental Soil Chemistry, Academic Press, San Diego, California.

19- Stratton G. W. 1987. The effect of pesticides and heavy metals towards phototrophic microorganisms. Review in Environmental Toxicology, 3: 71-147.

20- Templeton A. S., Spormann A. M., and Brown J. G. E. 2003. Speciation of Pb(II) sorbed by Burkholderia cepacia/goethite composites. Environmental Technology Letters, 37: 2166-2172.

21- Vasiliadoua I. A., Papoulisb D., Chrysikopoulosa C. V., Panagiotarasc D., Karakostad E., Fardisd M., and Papavassilioud G. 2011. Attachment of Pseudomonas putida onto differently structured kaolinite minerals: A combined ATR-FTIR and 1H NMR study. Colloids and Surfaces B: Biointerfaces, 84: 354–359.

22- Zhu J., Huang Q., Pigna M., and Violante A. 2012. Competitive sorption of Cu and Cr on goethite-bacteria complex. Chemical Engineering Journal, 179: 26-32.