Details of Award
NERC Reference : NE/J017795/1
A novel technique for the determination of Be-7, a potential tracer of significant environmental processes.
Training Grant Award
- Lead Supervisor:
- Dr JM Pates, Lancaster University, Lancaster Environment Centre
- Grant held at:
- Lancaster University, Lancaster Environment Centre
- Science Area:
- Freshwater
- Terrestrial
- Overall Classification:
- Freshwater
- ENRIs:
- Natural Resource Management
- Pollution and Waste
- Science Topics:
- None
- Abstract:
- Tracers play an important role in the study of environmental processes, allowing information to be acquired that cannot be gained directly, e.g. radioactive tracers enable the rates of processes to be determined through single measurements. Environmental tracers have the further advantage of not perturbing the system under study. Beryllium-7 (Be-7) (half-life = 53 days) is a naturally-occurring radionuclide produced in the stratosphere and troposphere, then delivered to the Earth's surface through precipitation. It binds strongly to particulate material, and is thus a good tracer for particulate material (soil or sediment) or other species that also bind strongly to soil (e.g. organic pollutants, metals). Be-7 has been utilised in a range of tracer studies to study processes as diverse as soil erosion, sediment fingerprinting and sediment mixing, but it remains an under-exploited tool. Its application has never become as wide-spread and routine as similar tracers, such as Cs-137 or Pb-210, although Be-7's shorter half-life means that it can be used to study rapid processes that cannot be detected using these longer-lived nuclides. The major barrier to the exploitation of Be-7 is the analytical method currently employed (gamma spectrometry). The sample throughput is low (~ 7 samples per week per detector), restricting the number of samples that can be measured before they decay to below the detection limit, and the required sample mass is high (50 - 100 g). For existing applications acquiring these high sample masses can be timeconsuming, technically challenging and expensive. For example, soil erosion studies require large (700 - 2500 cm2) soil cores to be sectioned at 2 mm increments, smaller cores have to be pooled in marine and lake sediment studies, and studies of particulate material in lakes and rivers require 1000s L water to be filtered using high-volume pumps. Thus, this tracer has never moved beyond a specialist application. Here, a new approach to Be-7 determination using liquid scintillation spectrometry (LSS) is proposed. This approach would have the advantage of a significantly increased sample throughput (x 20) using much smaller samples, allowing this powerful tracer to become fully utilised by the environmental science community. The project has three objectives. Objective 1 is to develop and optimise the LSS analysis of Be-7, with the aim of providing a rapid throughput measurement technique. Objective 2 is to develop a protocol to allow the straightforward separation and purification of Be-7 from a range of environmental matrices. This work will be conducted in collaboration with the Triskem Project Partner, who will be supplying the specialist resins required for this work and advising the student on methodological approaches. Once Objectives 1 and 2 are complete, the full methodology will be tested against the existing analytical method for validation purposes. Objective 3 is to demonstrate the utility of this new method and its capacity for extending the use of Be-7 as a tracer through two case-studies. The first will examine sediment mixing in lakes as a function of season (biological activity) and water depth, and investigate the impact of this mixing on chronologies derived from other radiotracers. The second will examine some of the fundamental assumptions made when applying this tracer to soil erosion studies. These assumptions have not been tested previously due to the constraints of the existing analytical method, and this work represents a fundamental need of the soil erosion tracing community. Training will be provided to the student with the following outcomes: (1) the student will become a competent radioanalytical chemist, a shortage specialism in the UK; (2) the student will gain awareness of the needs and challenges of a European SME; and (3) the methodology developed will open up Be-7 to a greater diversity of applications, with particular benefit to soil erosion studies.
- NERC Reference:
- NE/J017795/1
- Grant Stage:
- Completed
- Scheme:
- DTG - directed
- Grant Status:
- Closed
- Programme:
- Analytical Sci and Tech
This training grant award has a total value of £71,053
FDAB - Financial Details (Award breakdown by headings)
| Total - Fees | Total - Student Stipend | Total - RTSG |
|---|---|---|
| £13,812 | £48,285 | £8,957 |
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