Removal of Atrazine Contamination in Soil and Liquid Systems Using Bioaugmentation

✍ Scribed by Grigg, Brandon C.; Assaf, Nasser A.; Turco, Ronald F.

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 351 KB
• Volume: 50
• Category: Article
• ISSN: 1526-498X
• DOI: 10.1002/(sici)1096-9063(199707)50:3<211::aid-ps582>3.0.co;2-0

✦ Synopsis

Reported levels of atrazine in soils at pesticide mix-load sites can vary between 7É9 ] 10~5 mM and 1É9 mM. We report on a mixed microbial culture, capable of degrading concentrations of atrazine in excess of 1É9 mM. At initial concentrations of 0É046 M and 0É23 M, the mixed population degraded 78% and 21% of atrazine in soil (100 days), respectively. At the same initial concentrations in liquid cultures, 90% and 56% of the atrazine was degraded (80 days), respectively. Decreased degradation in soil samples may have resulted from atrazine sorption to soil surfaces or decreased contact between the population and the herbicide. In the 0É23 M system, we attribute incomplete degradation to phosphorous depletion. Data for carbon dioxide evolution was Ðtted to a three-halforder regression model, but we feel that there are limitations of the application of this model to atrazine degradation. The population uses the herbicide as a nitrogen source and little carbon is incorporated into biomass, as the energy status of carbons in the ring leads to their direct evolution as [14C]carbon dioxide. This situation contributes to an evolution pattern that, when Ðtted to the three-halforder model, results in underestimation of the biomass produced. Data from our study suggest that our mixed culture could be used for bioremediation of atrazine at concentrations up to and exceeding those currently reported for agrochemical mixing-loading facilities.