These methods and experimental setups are used to study the rates and mechanisms of biogeochemical processes by our graduate students, researchers, and collaborators.
Locations: PHY 222, PHY 227, and EIT 2015
Instruments/Measurement methods
The home-built high-resolution Multi Fiber Optode (MuFO) microsensors have been used to obtain continuous measurements of oxygen concentration. Operation of the MuFO system is based on luminescence quenching of the luminophore, in this case a metal-ligand complex, in the optical sensor. This system offers an affordable and highly customizable method for continuous monitoring of soil oxygen saturation.
Automated Soil CO2 Flux System (LI-COR LI-8100)
- The LI-8100 Automated Soil Flux System automates the collection of accurate and reliable soil gas flux data using an Infrared Gas Analyzer.
- The Infrared Gas Analyzer can measure carbon dioxide (CO2), methane (CH4) and water (H2O) concentrations.
- Our LI-8100A Analyzer Control Unit is interfaced with the LI-8150 Multiplexer, which allows one to monitor up to 16 chambers simultaneously.
Isothermal Calorimeter (TAM Air)
- Measures the heat produced or consumed by geochemical reactions and microbial metabolic processes
- Heat produced or consumed by microbial growth is related to energy dissipated by microbes as a result of metabolic processes, including growth and the redox cycling of elements such as C, N, S, and Fe
- Measures the heat produced over time and therefore gives information about reaction kinetics
- High sensitivity to detect heat produced and long-term temperature stability (±0.001 °C)
- Incubation temperature of samples can be well-controlled between 5 and 90 ºC
Portable Lab Spectral Induced Polarized (PSIP) Instrument
- High performance multichannel geophysical instrument
- Optimized for laboratory SIP, measures conventional resistivity, time domain induced polarization and self-potential measurements
- The Spectral Induced Polarization response is measured by applying sine wave voltages in the frequency range between 1 mHz and 20 KHz
- Users can control and monitor the PSIP measurements with a standard web-browser which allows:
- Full and detailed control of all configurable test parameters
- User-controlled test runs
- Collecting and storing measurement data
MicroRespTM system
MicroResp™ is a microplate-based respiration system that enables the user to analyse up to 96 soil, sediment or water samples and test a range of carbon sources and/or replicates in a small compact space. MicroResp™ measures CO2 evolution over short periods (4-6 hours). Incubation temperatures can be controlled.
Experimental Set-ups
Automated computer-controlled soil column system
This home-built system is designed to examine time-dependent biogeochemical changes and fluxes in soil columns under controlled hydraulic conditions and well-defined initial and boundary conditions. The columns are equipped with pore water sampling ports and micro-sensors.
The home-built freeze-thaw soil column system simulates seasonal freeze-thaw cycles with realistic soil subsurface temperature gradients. This system is designed to examine time- and depth-dependent soil biogeochemical activity under freeze-thaw dynamics. The columns are equipped with pore water sampling ports and micro-sensors.
These flow-through reactors (FTRs) have been used to quantitatively assess biogeochemical reactions in variety of natural soils and sediments. The FTRs are designed to measure rates of biogeochemical reactions and yield kinetic parameters and information on reaction pathways that can be extrapolated to natural conditions.
Bioreactors (Applikon Biotechnology) x 3
Automated flow-injection switch-box for amperometric sensors
The automated flow-injection system consists of an 8-channel switch-box connected to a micro-sensor, which continuously measures the concentration of a target analyte or parameter (e.g., N2O, pH, EC). The switch box allows you to run up to 8 parallel flow-through reactor experiments.
Hyporheic Tank Systems
These home-built soil tank systems (60×50×25 cm3) have been used to mimic surface water--groundwater interactions in the hyporheric zone.
We use the Unisense Micromanipulator for precise positioning of micro-sensors to measure complete micro-profiles with high spatial resolution down to 10 µm, while on the x- and y-axis the sensor position can be manipulated with 100 µm precision. The Micromanipulator is mounted on a heavy laboratory stand for in-situ measurements, e.g. in sediments, pit soils or muddy fields.
Home-built fraction collector. Pre-programmed computer-controlled water sampler.
- MaxQ 7000 Benchtop Water Bath Shaker
- Bath chamber dimensions: 41 cm L x 36 cm W x 19 cm D
- Speed: 40-400 rpm ± 10 rpm
- Continuous or timed operation 1-60 minutes
- Includes cooling coil SHK7000-37
- Temperature range below ambient: 5C - 80C ± 0.5C
Shakers (Thermo Scientific) x 2
- MaxQ mini 4450CC Digital shaker
- MaxQ 2000 (large shaker)
- Continuous or timed operation
- Both operate at 40-400 rpm ± 10 rpm
Microbial Manipulations
Autoclave
- Location: PHY 221
- Tuttnauer model 3850E Electronic Tabletop Autoclave with two trays
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28 cm W x 50 cm D x 2.5 cm H
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35 cm W x 50 cm D x 2.5 cm H
- Provides a clean work area during PCR preparation.
- The unit also includes a 254 nm ultraviolet light to sterilize tubes, flasks and pipelines between amplifications.
- Internal dimensions: 47" W x 23" D x 29" H
