Current Projects
Toxicity and Mobilization of Metals and Metal Mixtures in Sediments.
Farley, K.J.; Carbonaro, R.F. (co-PIs)
National Institute of Environmental and Health Sciences (NIEHS) (8/2006-8/2009), $387,644.
With funding from the National Institute of Environmental Health Sciences (NIEHS), we have been examining the speciation and cycling of arsenic, nickel, lead, cadmium, zinc and copper in sediments. In the presence of molecular oxygen, ferrous iron is capable of facilitating the oxidation of arsenite to arsenate. Our work has evaluated whether this mechanism is viable in sediments by examining the effects of sulfide and organic ligands on arsenic oxidation rates and mobility. Quantification of oxidation rates of Cd, Cu, Ni, Pb, and Zn sulfides are required to predict toxicity and mobilization of these metals in sediments. Laboratory experiments are underway to obtain experimental data for the oxidation of metal sulfide solid phases by molecular oxygen and to formulate a kinetic model for use in sediment toxicity and mobilization models.
Further Development of a Unit World Model for Critical Loadings of Metals in Aquatic Environments
Farley, K.J. (PI); Carbonaro, R.F.
International Commission of Mining and Metals (ICMM) (2006-2007), $50,000.
Through funding from the International Council of Mining and Metals (ICMM) and the U.S. EPA Center for Metals in the Environment, we are developing a "Unit World" Model for Metals (UWMM) to assess the ecological risks posed by metal inputs to aquatic systems. A Tier 1 version of the UWMM has been developed for lakes and includes dissolved and particulate phase transport, a simplified description of the biogeochemical cycling of organic carbon and sulfur, the complexation to organic carbon and inorganic ligands (as described by WHAM), metal hydroxide, carbonate and sulfide precipitation, and competitive interactions of metals and major cations to the biological site of action for water column and sediment-dwelling organisms (as described by the BLM). A user-friendly version of the UWMM has been developed using Microsoft Visual Basic and is being used to develop a relative hazard ranking for metals (Al, Cd, Co, Cu, Ni, Pb, Zn) and toxic organic contaminants for regulatory applications.
Former Projects
Effect of Urban Runoff on Seasonal and Spatial Trends in the Water Quality of the Saw Mill River
Carbonaro, R.F. (PI)
New York State Water Resources Institute & Groundwork Yonkers (6/2006-2/2007), $41,000.
The Saw Mill River is a tributary to the Hudson River in the Lower Hudson River Drainage Basin. The aim of this work was to conduct a year-long water quality monitoring program for the Saw Mill River from its headwaters in Chappaqua NY to Yonkers NY where it empties into the Hudson River. Surface water pH, temperature, conductivity, ammonia, nitrate, total phosphorous, and fecal coliform bacteria were monitored bi-weekly at 12 sampling locations. This project partnered with the Saw Mill River Coalition (a program of the non-profit community organization Groundwork Yonkers), which will use this information to coordinate action and planning among the 12 municipalities in the watershed through an existing inter-municipal agreement. This project was funded by the New York State Water Resources Institute.
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