Combined bioaumentation and biostimulation to clean up soil contaminated with high concentrations of atrazine

We developed a joint bioaugmentation and biostimulation approach for the clean up of soil contaminated with high (168.7 and 337.4 micrograms g-1) concentrations of the herbicide atrazine (2-chloro-4-(ethylamino)-6-isopropylamino-striazine). Pseudomonas sp. strain ADP (P. ADP) was used for bioaugment...

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Bibliographic Details
Published in:Environmental science & technology 2004-01, Vol.38 (2), p.632
Main Authors: Silva, Elisabete, Fialho, Arsenio M, Sa-Correia, Isabel, Burns, Richard G, Shaw, Liz J
Format: Article
Language:English
Subjects:
Bioremediation
Herbicides
Mineralization
Soil contaminants
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Summary:We developed a joint bioaugmentation and biostimulation approach for the clean up of soil contaminated with high (168.7 and 337.4 micrograms g-1) concentrations of the herbicide atrazine (2-chloro-4-(ethylamino)-6-isopropylamino-striazine). Pseudomonas sp. strain ADP (P. ADP) was used for bioaugmentation (approximately 107 cells g-1 soil), and citrate (concentration range 5.8-40 mg g-1 soil) and succinate (6.2-30.8 mg g-1) were used for biostimulation. The study soil had indigenous potential for atrazine mineralization (54.4 plus or minus 2% of 168.7 micrograms g-1 mineralized after 67 day), but rapid mineralization only took place after a prolonged acclimation phase (approximately 28 days). Inoculation with P. ADP alone resulted in a limited improvement in mineralization (e.g., 30.6 plus or minus 1% mineralization of 168.7 micrograms g-1 of atrazine in inoculated soil cf. less than 0.5% in noninoculated in 7 days). Quantification of surviving numbers of P. ADP revealed a 10-fold decline from initial levels. However, bioaugmentation together with citrate or succinate biostimulation markedly increased P. ADP cell survival and atrazine mineralization (e.g., addition of 11.6 mg g-1 of citrate increased mineralization of 337.4 micrograms g-1 of atrazine from less than 2 to 79.9 plus or minus 1% in 13 days). A critical parameter in determining the extent of atrazine mineralization by P. ADP was Cs:Natz (soluble carbon to atrazine nitrogen ratio): Cs:Natz is greater than 40 was required for maximal atrazine mineralization. We suggest our observations may be used as a framework for rational bioremediation of field soils contaminated with atrazine. [PUBLICATION ABSTRACT]
ISSN:0013-936X