Simultaneous Removal of Perchlorate and Nitrate Using Biodegradable Polymers Bioreactor Concept

Fang He, Haihong Zhou, Xiuju Wang, Liguo Wang

1School of Resources and Environment, University of Jinan, Jinan, China 2Shandong Provincial Engineering Technology Research Center for Ecological Carbon Sink and Capture Utilization, Jinan, China.

DOI: 10.4236/gep.2014.22007                

Abstract

Simultaneous perchlorate and nitrate removal from contaminated groundwater in one reactor has been realized with different methods in the past. The usage of biodegradable polymers as biofilm carriers and carbon source is new. Polymer in this paper was designed out of the copolymer of starch and polyvinyl alcohol. Under polluted water with 2 mg/L of perchlorate and 20 mg/L of NO3-N, it was possible to produce completely denitrification only for 5 h and below the detection limit to perchlorate within 9 h. Results indicating a significant impact of liquor pH on the biodegradation of but slight effect on nitrate reduction. Packed-bed reactor filled with polymer granules could remove 2 mg/L perchlorate and 25 mg/L NO3-N completely with influent flow rate of 1.17 mL/min. Morphological observation indicated the developed biofilm coverage on the outer surfaces of the carriers was dense and primarily composed of bacillus and coccus. The microbes in biofilm decomposed polymer, the chink and filament structure on the carrier surface developed, through metabolism and provided carbon source for them by releasing small organic molecules.

Keywords

Perchlorate; Nitrate; Biodegradation; Biodegradable Polymers; Biofilm

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Baidasa, S., Gao, B. Y., & Meng, X. G. (2011). Perchlorate Removal by Quaternary Amine Modified Reed. Journal of Hazardous Materials, 189, 54-61. http://dx.doi.org/10.1016/j.jhazmat.2011.01.124
[2]	Bauchard, D. C., Williams, M. K., & Surampalli, R. Y. (1992). Nitrate Contamination of Groundwater: Sources and Potential Health Effects. Journal of the American Water Works Association, 84, 85-90.
[3]	Choi, H., & JoAnn, S. (2008). Inhibition of Perchlorate Reduction by Nitrate in a Fixed Biofilm Reactor. Journal of Hazardous Materials, 159, 440-445. http://dx.doi.org/10.1016/j.jhazmat.2008.02.038
[4]	Coates, J. D., & Achenbach, L. A. (2004). Microbial Perchlorate Reduction: Rocket-Fuelled Metabolism. Nature Reviews Microbiology, 2, 569-580. http://dx.doi.org/10.1038/nrmicro926
[5]	Coates, J. D., & Anderson, R. T. (2000). Emerging Techniques for Anaerobic Bioremediation of Contaminated Environments. Trends in Biotechnology, 18, 408-412. http://dx.doi.org/10.1016/S0167-7799(00)01478-5
[6]	Ghosh, A., Pakshirajan, K., Ghosh, P. K., & Sahoo, N. K. (2011). Perchlorate Degradation Using an Indigenous Microbial Consortium Predominantly Burkholderia sp. Journal of Hazardous Materials, 187, 133-139. http://dx.doi.org/10.1016/j.jhazmat.2010.12.130
[7]	Herman, D. C., & Frankenberger, W. T. (1999). Bacterial Reduction of Perchlorate and Nitrate in Water. Journal of Environmental Quality, 28, 1018-1024. http://dx.doi.org/10.2134/jeq1999.00472425002800030036x
[8]	Shrout, J. D., Struckhoff, G. C., Parkin, G. F., & Schnoor, J. L. (2006). Stimulation and Molecular Characterization of Bacterial Perchlorate Degradation by Plant-Produced Electron Donors. Environmental Science & Technology, 40, 310-317. http://dx.doi.org/10.1021/es051130g
[9]	Srinivasan, R., & Sorial, G. A. (2009). Treatment of Perchlorate in Drinking Water: A Critical Review. Separation and Purification Technology, 69, 7-21. http://dx.doi.org/10.1016/j.seppur.2009.06.025
[10]	Wallace, W., Beshear, S., Williams, D., Hospadar, S., & Owens, M. (1998). Perchlorate Reduction by Amixed Culture in an Upflow Anaerobic Fixed Bed Reactor. Journal of Industrial Microbiology and Biotechnology, 20, 126-131. http://dx.doi.org/10.1038/sj.jim.2900494
[11]	Xu, J., Song, Y., Min, B., Steinberg, L., & Logan, B. E. (2003). Microbial Degradation of Perchlorate Principles and Applications. Environmental Engineering Science, 20, 405-422. http://dx.doi.org/10.1089/109287503768335904
[12]	Xu, J., Timble, J. J., Steinberg, L., & Logan, B. E. (2004). Chlorate and Nitrate Reduction Pathways Are Separately Induced in the Perchlorate-Respiring Bacterium Dechlorosoma sp. KJ and the Chlorate-Respiring Bacterium Pseudomonas sp. PDA. Water Research, 38, 673-680. http://dx.doi.org/10.1016/j.watres.2003.10.017
[13]	Zhou, H. H., Zhao, X., & Wang, J. L. (2009). Nitrate Removal from Groundwater Using Biodegradable Polymers as Carbon Source and Biofilm Support. International Journal of Environment and Pollution, 38, 339-348. http://dx.doi.org/10.1504/IJEP.2009.027234