7 results match your criteria: "Johns Hopkins University Center for Water and Health[Affiliation]"
J Environ Monit
December 2009
Johns Hopkins University, Bloomberg School of Public Health, Department of Environmental Health Sciences, Johns Hopkins University Center for Water and Health, USA.
This study examined the occurrence in wastewater of 11 aromatic biocides, pesticides and degradates, and their fate during passage through US treatment plants, as well as the chemical mass contained in sewage sludge (biosolids) destined for land application. Analyte concentrations in wastewater influent, effluent and sludge from 25 facilities in 18 US states were determined by liquid chromatography electrospray (tandem) mass spectrometry. Dichlorocarbanilide, fipronil, triclocarban, and triclosan were found consistently in all sample types.
View Article and Find Full Text PDFEnviron Sci Technol
September 2008
Johns Hopkins University Center for Water and Health, Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205, USA.
Mass balances are an instructive means for investigating the fate of chemicals during wastewater treatment. In addition to the aqueous-phase removal efficiency (phi), they can inform on chemical partitioning, transformation, and persistence, as well as on the chemical loading to streams and soils receiving, respectively, treated effluent and digested sewage sludge (biosolids). Release rates computed on a per-capita basis can serve to extrapolate findings to a larger scale.
View Article and Find Full Text PDFEnviron Sci Technol
May 2008
Johns Hopkins University Center for Water and Health, Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205, USA.
Three organic wastewater compounds (OWCs) were evaluated in theory and practice for their potential to trace sewage-derived microbial contaminants in surface waters. The underlying hypothesis was that hydrophobic OWCs outperform caffeine as a chemical tracer, due to their sorptive association with suspended microorganisms representing particulate organic carbon (POC). Modeling from first principles (ab initio) of OWC sorption to POC under environmental conditions suggested an increasing predictive power: caffeine (0.
View Article and Find Full Text PDFEnviron Sci Technol
June 2006
Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University Center for Water and Health, Johns Hopkins University, 615 North Wolfe Street, Room E6618, Baltimore, Maryland 21205-2103, USA.
The topical antiseptic agent triclocarban (TCC) is a common additive in many antimicrobial household consumables, including soaps and other personal care products. Long-term usage of the mass-produced compound and a lack of understanding of its fate during sewage treatment motivated the present mass balance analysis conducted at a typical U.S.
View Article and Find Full Text PDFChemosphere
January 2007
Johns Hopkins University, Bloomberg School of Public Health, Department of Environmental Health Sciences, Johns Hopkins University Center for Water and Health, Baltimore, MD 21205-2103, USA.
The antimicrobial agent triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol; TCS) is a member of a larger group of polychlorinated binuclear aromatic compounds frequently associated with adverse environmental and human health effects. Whereas the structure and function of TCS would suggest significant resistance to biotransformation, biological wastewater treatment currently is considered the principal destructive mechanism limiting dispersal of and environmental contamination with this compound. We explored the persistence of TCS in a typical full-scale activated sludge US sewage treatment plant using a mass balance approach in conjunction with isotope dilution liquid chromatography electrospray ionization mass spectrometry (ID-LC-ESI-MS) for accurate quantification.
View Article and Find Full Text PDFEnviron Res
January 2007
Department of Environmental Health Sciences, Johns Hopkins University, Bloomberg School of Public Health, Johns Hopkins University Center for Water and Health, Baltimore, MD 21205-2103, USA.
The antimicrobial compound triclocarban (TCC; 3,4,4'-trichlorocarbanilide; CAS# 101-20-2) is a high-production-volume chemical, recently suggested to cause widespread contamination of US water resources. To test this hypothesis, we developed an isotope dilution liquid chromatography electrospray ionization tandem mass spectrometry method for ultratrace analysis of TCC (0.9 ng/L detection limit) and analyzed low-volume water samples (200 mL) along with primary sludge samples from across the United States.
View Article and Find Full Text PDFEnviron Sci Technol
September 2004
Johns Hopkins University, Bloomberg School of Public Health, Department of Environmental Health Sciences, Johns Hopkins University Center for Water and Health, 615 North Wolfe Street, Room E6618, Baltimore, Maryland 21205-2103, USA.
Triclocarban, N-(4-chlorophenyl)-N'-(3,4-dichlorophenyl)urea, is a polychlorinated phenyl urea pesticide, marketed under the trademark TCC and used primarily as an antibacterial additive in personal care products. Despite its extensive use over several decades, environmental occurrence data on TCC are scarce. This is due in part to a lack of analytical techniques offering the desired sensitivity, selectivity, affordability, and ease of use.
View Article and Find Full Text PDF