UFI conducts a diverse array of experimental studies to characterize and quantify important ecosystem processes. Results of experiments are often represented in the form of kinetic coefficient values. Selected studies include:

• Sediment traps to determine sedimentation rates of organic and inorganic materials.
• Gas cones to capture (ebullative) gas released from sediments.
• Sediment coring for  paleolimnological studies, nutrient release and sediment oxygen demand (SOD) experiments.
• Sediment resuspension measurements
• dye studies to observe hydrodynamic processes

 

The important ecological and water quality roles of inorganic particles in aquatic ecosystems is emerging based on research conducted by UFI using SAX (scanning electron microscopy interfaced with automated image and x-ray analyses).  These are particles are central to the cycling of nutrients and various contaminants and in regulating clarity and the reflectance signal available for remote sensing.  UFI’s SAX research has been applied in multiple initiatives, including

• the role of inorganic particles in regulating clarity in the Finger Lakes of New York State
• the origins and modeling of turbidity in the water supply reservoirs of New York City’s water supply
• the characterization and optical impacts of inorganic particles in the Laurentian Great Lakes
• advancement of mechanistic approaches for remote sensing of water quality.

UFI has been advancing the technology of remotely controlled autonomous water quality monitoring systems.  These systems ("robots") consist of an onboard computer, telemetry and water quality sensors.   These systems have been deployed in Central New York State and the New York City drinking water watershed.  UFI has built several custom platforms including an Under-the-Ice system that can be deployed below the ice.

UFI has developed a robotic monitoring program for NYC’s water supply reservoirs.  These solar-powered, remote computer-driven robotic monitoring buoys collect vertical profiles of common metrics of water quality (temperature, specific conductance, dissolved oxygen, turbidity, and chlorophyll a). Collected data are returned to a base station in NRT. Much of the data collected by the robotic network is providing NRT data to stakeholders, meeting monitoring needs and supporting process studies.

UFI has developed, extended, and applied a number of thermodynamic and mass balance models over the past thirty years. These models solve the one-, two-, and three-dimensional diffusion and advection transport equations for both thermal energy and dissolved and particulate species.  Selected recent modeling applications include:

• Turbidity and eutrophication models for New York City drinking water reservoirs
• Transport models (1-, 2-, and 3-D) for Onondaga Lake
• Sediment models for Onondaga Lake
• Transport models for six lakes in Central New York

These models vary in their complexity (kinetic processes), time-frame, and specific systems to which they are applied. UFI supports a parsimonious modeling approaching, the development and use of models that have the appropriate level of complexity as required to credibly simulate the system and meet the goals of the model's end use.

UFI has been studying the redox conditions in lakes such as Onondaga and Cross Lakes over the past thirty years.  Most recently, UFI has made a significant contribution in the control of Methyl mercury (Hg) from lake sediments by applying this expertize in redox chemistry.

Methyl Hg is the toxic form of Hg, which is mobilized from contaminated sediments when anaerobic conditions prevail in overlying waters.  Such conditions exist in the bottom waters of Onondaga Lake.  UFI developed and successfully tested a treatment approach of nitrate (NO₃^-) addition that prevents mobilization of methyl Hg from the Onondaga Lake sediments.  This cost effective approach has multiple advantage over oxygenation technologies to prevent cycle of this toxic substance.

UFI has been conducting research on the optical characteristics of freshwater systems for over thirty years. UFI has placed particular emphasis on quantifying the roles various materials play in regulating water clarity. Clarity, the visibility of submerged objects, is closely coupled to the public's perception of water quality. Recently UFI has begun applying optics models that simulate signals observed by orbiting satellites.  UFI continues to expand its capabilities in this research area, including the acquisition of state-of-the-art optical instrumentation that is being deployed on New York State lakes and the Great Lakes.

UFI has a well instrumented laboratory for the measurement of components of absorption (CDOM and particulates) and particle size distributions. UFI’s field optics includes a spectral absorption and scattering meter (ac-s), spectral backscattering meter (bb9), and hyperspectral radiometers (HyperPro).

UFI conducts water quality monitoring on lakes, reservoirs and tributaries (systems).  This frequently includes water sample collection and the deployment of rapid profiling instrumentation.  Water samples are analyzed in our laboratory to quantify nutrients (e.g., phosphorus and nitrogen species), chlorophyll, turbidity, suspend solids, phytoplankton and zooplankton.  Instrumentation data provide

• information on thermal stratification
• presence of interflows (specific conductivity or turbidity)
• detailed chlorophyll structure
• light extinction

The rapid profilers also enable greater horizontal coverage than is often possible with sample collection.

These data are valuable in assessing the trophic state of a system, in understanding seasonal and annual changes and evaluated management actions.  UFI has published numerous papers with analysis based on field monitoring campaigns.