Current Graduate Students

Study of Die-off Rate of
Total Coliform at Low Temperatures

Pathogens are viable in the environment for months to years. Some of the factors affecting pathogen viability in the environment are nutrient availability, moisture content, pH, and temperature. In cold regions, it is assumed that low temperatures help to preserve pathogens for longer times. Human and animal wastes thrown into landfills contain pathogens. Pathogens become metabolically inactive in the winter due to the cold temperatures, but revive again when temperature increases. Water flowing over the contaminated site carries the pathogens and may ultimately get mixed up with a drinking water source.

My research involves taking Total Coliform as an indicator of the presence of fecal pathogens in the soil. I am observing the die-off characteristics of total coliform in soil samples containing different moisture contents and kept at different temperatures.

Anaerobic Gas Production in Arctic and Sub-arctic Soils

I am studying anaerobic gas production in arctic and sub-arctic soils. My research involves the development of a model for anaerobic gas production through laboratory experiments of soil samples. I then apply this model to soil samples (collected through the summer of 2003, near Smith Lake at the University of Alaska Fairbanks campus), in order to predict the amount of gas production in these soils. I measure gas production by incubating soil samples in an anaerobic environment and measuring the pressure change with a pressure gauge. I then try to discover the amount of methane present in the gas using gas chromatography.

This project is important on a global scale because methane and carbon dioxide, the most prevalent gases produced by anaerobic metabolism, are greenhouse gases. An increase in anaerobic gas production in arctic and sub-arctic soils would provide a positive feedback to global climate change through the production of greenhouse gases.

William
'Bob'
Bolton

Hydrologic Processes and Moisture Dynamics
in Areas of Discontinuous Permafrost

My research involves studying the hydrologic processes and moisture dynamics in areas of discontinuous permafrost. I am also interested in studying how disturbances, such as wildfire, affect these processes. Permafrost plays an important role in the hydrology of sub-arctic watersheds. Ice-rich conditions at the permafrost table do not allow significant infiltration, resulting in decreased response time to precipitation events (including snowmelt), limited subsurface, and low base flows between precipitation events. I am applying a process based, spatially distributed model to the Caribou-Poker Creeks Research Watershed, located Northeast of Fairbanks, Alaska, with the aim of quantifying the hydrologic processes in the sub-arctic environment.

Pathways of Fecal Contamination in Open Water Systems

Eek is a village in the Yukon-Kuskokwim Delta region that does not yet have piped water and sewer. A washeteria provides treated water, but traditional water sources, such as ice and rain from roof catchments, are still used. Because water must be carried into the home and wastewater carried out in an open system (not piped) there is increased risk of diseases spread by the fecal-oral route.

In my research I am seeking to determine the major pathways of contamination outside the home. Using coliform and E. coli, indicators of fecal pollution, I am looking for significant sources and mechanisms of transport. Sources of fecal bacteria may include a honeybucket disposal site, dogs, birds, and other wildlife. Some transport mechanisms of interest are surface flow, ATVs, snowmachines, and boots.

Concerns include contamination of water sources and contamination during transport and storage. An understanding of how pathogens move in the community can help Eek and similar communities take measures to protect public health by preserving the quality of drinking water.

Modeling Snow Distribution and Melt for the Kuparuk River Basin

I am studying the snow distribution and snowmelt of the Kuparuk River basin from 1996 to the present. The Kuparuk River is a northern draining basin that originates in the Brooks Range and empties into the Arctic Ocean. Its snow distribution is affected by many variables such as slope, aspect, elevation, vegetation, and wind direction.

There are over 80 sites in the basin at which SWE measurements have been made. These measurements are taken at the various land types to study the snowmelt and causes for its pattern. Typically, snowmelt begins in the south (at the higher elevations) and proceeds northwards; However, in past years other patterns have been observed.

My goal is to model the snow distribution and melt to understand how changes in its variables cause an alteration in the snowmelt pattern.

Pieter A. P.
deHart

Biogeochemical Reconstruction of the North Pacific: Looking at Ecosystem Changes using Marine Mammals

My research utilizes stable isotope analysis to look at the population biology and ecology of marine mammals. Specifically, I am examining the temporal and spatial patterns in the carbon and nitrogen isotopes of Steller sea lion diet, which may contribute to the precipitous decline in their abundance and distribution in the North Pacific Ocean. Additionally, I am using oxygen and hydrogen isotopes to elucidate the nutrient processing throughout an ecosystem in organic materials. By examining the values of O-18 and Deuterium in Bowhead whale baleen, I am refining and redirecting our current knowledge of bowhead seasonal migration and feeding behavior.

The Relationship between North Slope Lake Watershed Characteristics and Water-Use for Facility Operations and Winter Ice Road and Pad Construction

For many years, the oil industry and support services have withdrawn water from freshwater lakes to build ice roads and pads in order to increase access to remote sites and decrease operations and maintenance costs. This technique is quite important to the oil industry in that it allows oil field development or maintenance while avoiding the environmental disturbance associated with construction of gravel roads and pads. Facilities also use freshwater lakes for year-round facility operations, including potable water supplies, drilling mud and cementing operations, dust control and general maintence activities.

Design, permitting, and evaluation of water use activities require an understanding of the recharge potential of lakes, natural processes changing lake water volumes, and associated changes in biogeochemical indices. Short-term versus long-term variations in natural hydrologic processes and variations in water use patterns are also issues design engineers and resource managers must consider. This project focuses on improving efforts in understanding both physical and chemical lake processes and their associated watersheds.

Annual Water Balance
in Northern Latitude Watersheds

To better understand macro-scale arctic hydrology, the annual water balance of 39 northern-latitude watersheds (ranging in latitude from 44º N to 79º N) will be compared based on climatic and physiographic characteristics. The primary descriptors of the annual water balance are the runoff ratio (Annual Discharge/ Annual Precipitation) and evapotranspiration (ET) ratio (Annual ET/ Annual Precipitation). These values explain proportionally what part of the total annual input (precipitation) is lost as runoff and what is lost as evapotranspiration. The question is how well can the basin-to-basin differences of runoff and ET be deduced from certain watershed parameters such as topographic conditions (median slope, aspect, relief ratio), major vegetation/biome classification, permafrost extent, soil texture, and geographic location.

Thermokarst Evolution and Sediment Transport
in a Sub-arctic Watershed

My research focuses on rapid thermokarst development in the Caribou Poker Creeks Research Watershed (CPCRW), a relatively new feature in this predominantly discontinuous permafrost region. A thermokarst was initiated by permafrost degradation and precipitated primarily by a rain event occurring in July 2003.

Field studies of thermokarst evolution and sediment transport involved installing sediment traps, measuring discharge, and collecting water samples for suspended sediment concentration analysis. Rapid morphologic changes of the thermokarst site will be examined by comparing topographical surveys carried out during the summer of 2004 with surveys planned for summer of 2005.

Laboratory analyses were carried out to determine the amount of sediment being transported at different points along the channel. Preliminary data on suspended sediment concentration indicate that higher sediment transport occurs during and after rainfall events. The high sediment transport is a clear indication that erosion of the area is an active and ongoing process. Future work will involve analyzing grain size distribution of the sediment samples and investigating the groundwater movement within the active layer. The ultimate goal of the study is to understand the correlation between the suspended sediment transport and the rate of evolution of the thermokarst.

Dynamics in Energy and Water Exchange
Between Soil and Atmosphere

My interest lies in examining the hydrology of and climate change in the arctic region, where the presence of permafrost is of decisive importance in shaping both the physical and biological regimes. Dynamics in the energy and water exchange between the soil and the atmosphere, especially soil moisture fluctuations, constitute my research focus. The study area in central Seward Peninsula, Northwestern Alaska, also includes the effects of a fire on the surface energy balance at a tussock tundra site. The hydrologic studies as a part of the Barrow SNACS Project involves modeling soil moisture variations, which will be shared with ecosystem, oceanic and atmospheric modelers. When I am not working on my research, you may find me on my telemark skis or ice climbing.

Derek "Dan"
Miller

Field Investigation of Water Movement
in Frozen Soils

Water movement at sub-zero temperatures distinugishes permafrost hydrology. The arctic winter effects substantial changes in the spatial distribution and density of soil components. The winter's great length ensures that these changes are important components of active layer dynamics. In particular, the soil solution chemistry can reflect changes in phase density via transport and exclusion of dissolved species during freezing and through changes in pH and redox potential.

This study addresses the following problems: 1) what is the distribution of moisture in the active layer from one summer to the next? 2) what is the magnitude and direction of moisture migration within the active layer, across the boundary layer and as a component of the mass balances? 3) what changes in soil water chemistry of the unfrozen phase result?

Changes in the soil water phase density can be observed via their effect on hydrological, thermodynamic and chemical properties of the soil. The direct measurement of liquid water or ice dependent properties (for example, determination of total water content by weight or of bulk soil dielectric conductivity) allows us to trace moisture movement over time. Soil temperature time series, coupled with surface energy flux data, give information regarding phase change. Such phase changes affect the concentration of liquid water in the soil solution and change the chemistry of the soil water. Via destructive and in situ liquid water and ice content determination as well as chemical analyses of the soil solution, we trace changes in winter moisture distribution and their influence on soil water chemistry.

Santosh Patil

PECTIN AS A BIOSORBENT FOR HEAVY METALS

These heavy metals are persistent in the environment, can accumulate in the food chain, and are lethal to humans. This demands a reliable, efficient, low cost technique for removal of heavy metals from wastewater from wastewater, for example from mine waste streams. Metal biosorption is usually reversible, which allows regeneration of the metal saturated sorbent material through desorption (e.g. with acids). This renders the reuse of the biosorbent and the recovery of the desorbed metal possible.

Pectin, a structural polysaccharide present in plant cell walls, is a biopolymer structurally similar to alginate, a molecule that is often responsible for the high metal uptake by algal biosorbents. Based on the structural similarity between alginic acid (present in algae) and pectin, it may be expected that pectin rich bio-wastes may be as good a biosorbent material as brown algae. My research focuses on obtaining samples of pectin-rich waste materials, characterizations of acidic properties and pectin content, experiments on the metal biosorption by different pectinous materials, evaluation of experimental data using isotherms and comparison. The effects of pH and ionic strength on the sorption by chosen material will be studied and suitable mathematical model can be developed.

Correlating Oxygen Uptake Rate and 5-day Biochemical Oxygen Demand in View of Process Control and Monitoring: Fairbanks, Alaska

Respirometry is used to measure the 5-day biochemical oxygen demand (BOD5) of waste effluent streams. Respirometry measures the respiration rate of microorganisms (oxygen uptake rate (OUR)). This data will be used to develop diurnal trends in the flow and waste strength experienced by the Fairbanks wastewater treatment facility.
Shock loadings are experienced by the wastewater treatment facility on encountering septic waste. The absence of primary clarifier in the treatment scheme makes time dependency critical. Short time frame correlations will be developed between OUR and BOD5 for the nature of waste experienced in Fairbanks.

The facility uses pure oxygen in the aeration basin and has an on-site oxygen production plant. Diurnal variations in waste strength and flow renders the activated sludge system uneconomical, especially due to substantial oxygen production costs. Using correlations will aid in rapid prediction of the waste strength. This information can be used to model the required aeration trends, given the plant specifications and uniqueness. Aeration trends will be modeled as a function of waste strength variation with time of day and variations along the length of the aeration train. The predicted aeration strategy will be compared to the presently practiced strategy. This will help ascertain an optimal control that can be applied on site with special emphasis on cost efficiency

This research aims at understanding a unique sewage generation and treatment pattern, with emphasis on process control, engineering optimization, and cost benefits in a traditionally expensive yet necessary treatment scheme

Techniques for improved membrane filtration of water and wastewater

Steady operation of membrane plants requires careful management of membrane fouling. Even though it might be impossible to prevent, the impact can be limited by various techniques.

One of these options is gas sparging. That method improves the cross flow hydrodynamics near the membrane surface. Gas sparging, i.e. injecting of air into the feed of the membrane to generate a gas liquid two phase cross flow operation, helps to maintain a stable permeate flux over longer time-periods

Another opportunity is the technique of backwashing with permeate. While the feed pump is running, every few minutes filtrate, opposed to the normal filtration direction, is pressed through the membrane. In this moment, the applied backpressure must be higher then the working transmembrane pressure. The fouling and scaling material ideally lifts up from the membrane, because of the back flow and leaves the module, because of the feed flow.

Objective of the research it is to investigate both methods of fouling prevention for water and wastewater membrane filtration and to investigate their particular impacts while simultaneously deployed. Furthermore first steps related to air sparging and backwashing toward optimized operations for fouling prevention are intended.

Erin Strang

Historic Water Use on the Seward Peninsula

My research will document the historic use of water for industrial and domestic purposes on the Seward Peninsula. Preliminary results suggest that water use in the Nome Mining District decreased proportionally with the decline of placer mining operations. Water was used in placer gold mining operations on the Seward Peninsula to run hydraulic giants, sluice boxes, and other mining equipment. Because water was one of the limiting factors in mining operations, a series of ditches diverted nearly all available surface water in the Nome mining district between 1905 and 1914 for industrial use. The domestic water demand, that is, water used for drinking, cooking and cleaning, increased over the past 40 years as piped water and sewer systems were installed in many villages. Domestic demand can increase by 900% when a community installs piped water. The increase in demand corresponding to this change of delivery system can be seen in the difference between water consumption in a village with a central watering point and a village where every house is connected to a piped water and sewer system. I am using historical pressures on the freshwater resource to better understand the vulnerability of the resource now and in the future.

Quantifying Hydrologic Dynamics in a Changing Environment

The climate in the Arctic has warmed over the past 30 years, and several studies suggest that there will be significant polar amplification of global warming in the future. The Seward Peninsula lies at the southern boundary of permafrost, and is underlain by relatively warm, unstable discontinuous permafrost that is particularly susceptible to the effects of climatic changes.

In general, warmer temperatures cause reductions of permafrost and an increased active layer thickness, allowing more surface water to infiltrate into the groundwater table. Because the hydrologic cycle and permafrost are so inexorably linked, slight changes in permafrost may have a major impact on hydrologic processes. The objective of my research is to determine how the availability of freshwater on the Seward Peninsula has changed in the recent past, and how climate-induced changes in the permafrost and hydrologic cycle will affect water quality and availability in the future.

Oxygen Isotope Composition, Insects,
and Mean Annual Temperatures

The oxygen isotope composition (d¹⁸O) of fossil aquatic insects preserved in arctic lake sediments may faithfully record past air temperatures. These data, derived from dated lake sediments, can be used to reconstruct past temperatures. My goal is to examine the modern relationship between mean annual temperatures (MATs) and the d¹⁸O of insect (midge larvae) fossils by analyzing lake water and larvae in modern surface sediments from suitable Alaskan lakes across a climate gradient.

Additionally, I aim to determine if factors other than water (e.g., diet) incluences the d¹⁸O of insects (midge larvae) by rearing midges in the laboratory and controlling their diet and water sources. Ultimately, I will apply this technique to the analysis of lake sediments from Alaska and Iceland, extending the record of Holocene (the last ~10,000 years) temperature changes in the Arctic beyond the instrumental record.

Hong Zhang

Crab Shells as Biosorptive Materials

Biosorption is defined as the passive uptake of heavy metals by biomass. This process combines the advantages of being, on the one hand, highly efficient at metal removal and, on the other hand, much more cost effective than comparable techniques such as ion exchange.

One reason for this cost effectiveness is that waste products from other industries can be used as biosorbents. For example, Alaska's fisheries industry produces large quantities of crab shells as waste products. These crab shells contain chitin as one of their main constituents, which is suitable binding anionic metal complex.

My project is to find a suitable processing method for treating crab shells and to study the binding capability of the new material when it is used to remove anionic metal complex from wastewaters such as mining tails. This project will benefit both Alaska's seafood industry and mining industry.