Pioneering high-frequency in-situ water quality sensors to improve the understanding and management of non-linear dynamics of pollutant fate and transport in complex flowing systems Research project

Birgand, Francois

Description:

Significance/Relevance

Birgand’s program has developed world-leading high-frequency field sampling technologies to capture the temporal variability of flow and concentrations combining newly commercially available in-situ high frequency (e.g., 15 min) spectrophotometers with smart statistical techniques. This has lowered uncertainty on the bulk trend at an unprecedented and remarkable level, but would tremendously benefit from complementary approaches.

While on sabbatical leave in the fall of 2017 at the University of Bristol, UK, Dr. Birgand had a chance to connect several times with Dr. Krause and his team at the University of Birmingham, UK. Dr. Krause’s lab pioneers the development of fluorescence based smart tracer systems that are used to analyze the microbial and metabolic processes occurring in streams and at the sediment-water interface that control nutrient spiraling and pollutant turnover. The application of Dr. Krause’s smart tracer technologies therefore provide a unique opportunity to be combined with Dr. Birgand’s sampling technologies and high-frequency detection of solute concentrations in order to for the first time ever combine the detection of high-frequency dynamics of variability of flow and nutrient concentrations through time (Birgand) with a functional analysis of the drivers and controls of nutrient spiraling as well as metabolically active transient storage (Krause).

Being able to do both leverages the information generated by each technique, and is the natural reason for which Birgand and Krause have decided to work together. Krause is particularly interested in a micro-volume in situ analyzer that Birgand’s team has developed, which gives access to both spatial and temporal resolution water quality data. This gives Krause and his team access to crucial information on the fate of nutrients and pollutants in the very reactive near stream area.

Following meetings in Birmingham, Birgand and Krause have decided that the best way to start a collaboration is to bring respective expertise to each other’s’ field sites, where they will, with their respective students, teach and learn respective instruments/techniques.

Feasibility

Birgand’s team has monitored over the last four years a stream restoration, before, during, and currently after restoration, using in situ instruments to obtain ‘continuous’ (i.e., every 15 min) flow and concentrations, a feat that no one in the world has done or at least reported before. The restored stream is thus a new aquatic entity where nutrient turnover and dissipation processes rely on substrate which origin is controlled and generally known. This leverages the potential for stream metabolism experiments to generate more easily interpretable data that will nicely complement the bulk observations derived from continuous monitoring. This will be done using Krause’s techniques and expertise.

Birgand and Krause have already agreed that Brekenfeld would also come in Raleigh in 2018 to build under Birgand’s team guidance, a micro-multiplexed sampler for in situ water quality monitoring of porous media, particularly those around streams, which will leverage Krause’s approach to better trace in time and in space the transport and fate of nutrients and carbon in his study streams in the UK. Brekenfeld did come to Raleigh to build the instrument and Birgand joined Krause’s team to their field sites in the UK in June 2019 to help implement the in situ micro volume sensors and learn on additional tracer techniques, which Krause’s team has applied on their study sites.

Region(s)/Country(s):

Dates:
11/22/2018 - 06/30/2020

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