Enhanced biological removal of Cr(VI) in Continuous Stirred Tank Reactor (CSTR) using Aspergillus sp.

Mousumi Sen

Abstract
Biological removal of Cr(VI) from aqueous solution was studied in batch and continuous mode of operation using the growing Aspergillus sp. Continuous removal of Cr(VI) was studied in Continuous Stirred Tank Reactor (CSTR) maintaining the microorganism in living or biologically active state. In batch bioreactor, the growth and Cr(VI) removal by the organism were studied at different initial Cr(VI) concentration at pH 5.0. Whereas, in continuous mode of operation both single and two stage reactors were also studied for Cr(VI) removal. Batch studies indicated the maximum specific Cr(VI) removal to be 41.2 mg.g^-1 at pH 5.0 and at 500 mg L^-1 initial Cr(VI) concentration. However, in continuous mode of operation, the maximum specific Cr(VI) removal was found to be 39.4 mg.g^-1 after first stage operation with an additional 39.32 mg.g^-1 obtained in the second stage operation. Hence, these results indicated that the continuous mode of operation could be the ideal operational strategy in which the process could be operated for longer duration with a enhanced Cr(VI) removal.

Keywords
Hexavalent chromium; Heavy metal pollutants; Batch and continuous operation; Specific growth rate; Two stage reactor.

DOI
10.21472/bjbs.050904

Full text
PDF

References
APHA - American Public Health Association. Standards methods for the examination of water and wastewater. 17. ed. Washington: American Public Health Association, 1989.

Borst-Paweles, G. W. F. H. Ion transport in yeast. Biochimica et Biophysica Acta (BBA) - Reviews on Biomembranes, v. 650, no. 2/3, p. 88-127, 1981. https://doi.org/10.1016/0304-4157(81)90002-2

Dursan, A. Y.; Ulsu, G.; Cuci, Y.; Aksu, Z. Bioaccumulation of copper(II), lead(II) and chromium(VI) by growing Aspergillus niger. Process Biochemistry, v. 38, no. 12, p. 1647-1651, 2003. https://doi.org/10.1016/S0032-9592(02)00075-4

Germain, L. E.; Patterson, E. Plating and cyanide wastes. Journal of the Water Pollution Control Federation, v. 46, p. 1301-1315, 1974.

Gharib, M. M.; Gadd, G. M. Evidence for the involvement of vacuolar activity in metal(loid) tolerance: vacuolar-lacking and -defective mutants of Saccharomyces cerevisiae display higher sensitivity to chromate, tellurite and selenite. Biometals, v. 11, no. 2, p. 101-106, 1998. https://doi.org/10.1023/A:1009221810760

Llovera, S.; Bonet, R.; Simon-Pujol, M. D.; Congregado, F. Effect of culture medium ions on chromate reduction by resting cells of Agrobacterium radiobacter. Applied Microbiology and Biotechnology, v. 39, p. 424-426, 1993. https://doi.org/10.1007/ BF00192105

Middleton, S. S.; Latmani, R. B.; Mackey, M. R.; Ellisman, M. H.; Tebo, B. M.; Criddle, C. S. Cometabolism of Cr(VI) by Shewanella oneidensis MR-1 produces cell-associated reduced chromium and inhibits growth. Biotechnolology and Bioengineering, v. 83, no. 6, p. 627-637, 2003. https://doi.org/10.1002/bit.10725

Millar, G. L. Use of dinitrosalicylic acid reagent for determination of reducing sugar. Analytical Chemistry, v. 31, no. 3, p. 426 428, 1959. https://doi.org/10.1021/ac60147a030

Muter, O.; Patmalnieks, A.; Rapoport, A. Interrelations of the yeast candida utilis and Cr(VI): metal reduction and its distribution in the cell and medium. Process Biochemistry, v. 36, no. 10, p. 963-970, 2001. https://doi.org/10.1016/S0032-9592(01)00136-4

Peña-Castro, J. M.; Martínez-Jerónimo, F.; Esparza-García, F.; Cañizares-Villanueva, R. O. Heavy metals removal by the microalga Scenedesmus incrassatulus in continuous cultures. Bioresource Technology, v. 94, p. 219-222, 2004. https://doi.org/10.1016/j.biortech.2003.12.005

Sen, M.; Dastidar, M. G.; Roychoudhury, P. K. Comparative studies of batch and continuous biological treatment of Cr(VI) using Fusarium solani. Enzyme and Microbial Technology, v. 41, no. 1/2, p. 51-56, 2007. https://doi.org/10.1016/j.enzmictec.2006.11.021

Shugaba, A.; Buba, F.; Kolo, B. G.; Nok, A. J.; Ameh, D. A.; Lori, J. A. uptake and reduction of hexavalent chromium by Aspergillus niger and Aspergillus parasiticus. Journal of Petroleum & Environmental Biotechnology, v. 3, no. 3, p. 1-8, 2012. http://doi.org/10.4172/2157-7463.1000119

Srinath, T.; Verma, T.; Ramteke, P. W.; Garg, S. K. Chromium(VI) biosorption and bioaccumulation by chromate resistant bacteria. Chemophere, v. 48, no. 4, p. 427 435, 2002. https://doi.org/10.1016/S0045-6535(02)00089-9

Sudha Bai, R.; Abraham, T. E. Biosorption of Cr(VI) from aqueous solution by Rhizopus nigrificans. Bioresource Technology, v. 79, no. 1, p. 73-81, 2001. https://doi.org/ 10.1016/S0960-8524(00)00107-3