Antimicrobial chemicals in biosolid amended soils: persistence and effects

University Of California-Davis, Davis CA

Investigators

Abstract

ABSTRACT CBET- 0756074 Young, Thomas University of California at Davis Antimicrobial chemicals in biosolid amended soils: persistence and effects If TCS and TCC accumulate in biosolids-amended soils to the point where soil fertility or groundwater quality is adversely impacted, the agricultural market for these materials could disappear very quickly. This would require other outlets for biosolids disposal, all of which would likely be more costly and less environmentally friendly than land application. This fact, combined with the potential threats to human health posed by TCS/TCC, justifies further study regarding the fate and impact of these compounds in soils where biosolids are land applied. The proposed work is to investigate the impact of triclosan (TCS) and triclocarban (TCC) on soil microbial community structure, biomass, and diversity. It would also investigate the role that these communities play in degrading TCS/TCC and cycling of nitrogen in soil. Lastly, it would also elucidate environmental conditions that favor biotransformation of the compounds in soils, determine process rates, and identify types of microorganisms involved in the transformation. The hypotheses to be tested are well defined, and the experimental approaches to test the hypotheses are well-designed. Preliminary data collected by the research team suggests that this approach will be successful and yield valuable information. The experimental plan includes the use of a variety of complimentary techniques for characterizing the community structure in combination with techniques to determine function and potential activity of the microbial populations. Three soil types will be tested in order to include soils representative of those that have had long-term exposure to TCS/TCC, those that have not had long term exposure, those that are primarily aerobic, and those that are anaerobic.