Oxford mathematicians in Indian arsenic collaboration

The GCRF funds research partnership between Oxford’s Mathematical Institute and India’s IIT Kharagpur to model novel soil-based filter.

The Ganges-Brahmaputra Delta is a global hotspot for arsenic groundwater contamination. Naturally occurring arsenic concentrates in water drawn from deep tube wells, creating a major public health issue in West Bengal and Bangladesh, described as the “largest mass poisoning of a population in history”.

Researchers at the Department of Chemical Engineering at the Indian Institute of Technology (IIT) Kharagpur, led by Prof Sirshendu De, recently developed a novel technology that uses the soil bed to filter arsenic. This product has already been piloted in three communities in India, serving more than 5000 people.

While the spread of single contaminants through porous media is well-known, transport, when multiple contaminants interact through a composite soil bed, is poorly understood. In these pilot areas, pesticides, fertilisers, and heavy metals are all present in the environment and it is unclear how their interaction impacts the effectiveness of the filter.

To develop a better understanding of these processes, IIT Kharagpur has enlisted the help of Oxford mathematicians Ian Griffiths and Sourav Mondal. The Oxford team will employ mathematical modelling techniques to gain insight into the action of the new filter and assess how this emerging technology can realise its full potential to remove contaminants from the soil and groundwater.

The project, which received funding from the Engineering & Physical Sciences Research Council’s (EPSRC) Global Challenges Research Fund (GCRF) on July 20, will commence at the beginning of August and run for 7 months. During this time, the Oxford team will work to derive a series of predictive mathematical theories based on asymptotic and computational techniques to understand the chemical transport and fluid dynamics processes taking place within the filter. The models will be combined with experiments and field data gathered by IIT Kharagpur to improve the prediction of how these chemicals spread.

The researchers hope that this collaboration will instigate future UK–India research and development co-operation and boost science and technological endeavours aimed at providing solutions to environmental problems, particularly those faced by low-income countries.

The REACH Programme’s first Partnership Funding round recently awarded Catalyst Grants to two arsenic-related projects in Bangladesh: 1) Arsenic Precision Innovative Rapid Easy-to-use Test (AsPIRE Test) and 2) Co-occurrence of heavy metal and antibiotic resistance in microorganisms due to arsenic contamination in water insecure areas of Bangladesh. Further detail of these, and the other REACH Catalyst Grants, can be found here.

Grants catalyse 12 new water security projects


Oxford’s REACH programme announces the funding awards from its first Partnership Funding round.

Over £550,000 has been awarded through our Partnership Funding to 12 projects in the first call for Catalyst Grants. The one-year projects span eleven countries in Africa and South Asia, and will work at the interface of water security and poverty reduction research and practice.

Rosanna Bartlett, REACH Partnership Funding Manager, said: ‘I’m delighted to announce these new projects which will advance REACH’s goal to improve water security for five million poor people. They have been chosen both for their novel science ideas and potential to deliver significant and sustainable impact.’

Dr Rob Hope, REACH Director, said: ‘Our understanding of water security moves beyond siloed and traditional approaches which separate drinking water services from water resources. We’re pleased to see many of these projects addressing these under-researched linkages, which will unlock opportunities for both human development and economic growth.’

There will be at least one more call for Catalyst Grants (£10,000-50,000), as well as a call for Major Grants (up to £500,000) during the course of the REACH programme. These will be announced on the Partnership Funding page.


Sensor technology for rapidly assessing water quality risks for vulnerable users (TRIGR)
British Geological Survey, University of Malawi – The Polytechnic, WaterAid, Chelsea Technologies Group

Co-occurrence of heavy metal and antibiotic resistance in microorganisms due to arsenic contamination in water insecure areas of Bangladesh
International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Swiss Federal Research Institute for Aquatic Science and Technology (EAWAG), Oregon State University, Emory University

Enhancing the Delta Dynamic Integrated Emulator Model and concepts to support REACH goals
University of Southampton, Institute of Water and Flood Management (IWFM) at the Bangladesh University of Engineering and Technology (BUET)

Arsenic Precision Innovative Rapid Easy-to-use Test (AsPIRE Test)
The Bio Nano Centre Limited, University of Dhaka

Livelihoods from Enhanced water Access for the Poor in Slums (LEAPS)
Loughborough University, National Water and Sewerage Corporation

Understanding women’s water, sanitation, and hygiene (WASH) vulnerability
Burkina Faso
Stockholm Environment Institute, CEFAME

Water security risk science: local monitoring for participatory resource management (AMGRAF-WSRS)
Newcastle University, International Water Management Institute

Pastoralist women and water: understanding the ways in which women’s disempowerment contributes to water security risks
Centre for Humanitarian Change (CHC), Northern Rangelands Trust

Target Towns Research Action Programme (RAPTT)
London School of Hygiene and Tropical Medicine (LSHTM), Centre for Infectious Disease Research in Zambia (CIDRZ), Oxford University, University of Leeds, Georgia Institute of Technology

Safer water H20 access through Improved monitoring information to Expand supply and Local Demand at water kiosks in Goma, DRC (SHIELD)
Democratic Republic of Congo
SeeSaw, Humanitarian Assistance for Development NGO

Establishing a water quality monitoring network in mid-western Nepal
Eawag, HELVETAS Swiss Intercooperation

Water law reform to improve water security for vulnerable people in Africa (SELARE)
Kenya, Malawi, Uganda, Zimbabwe, South Africa
Pegasys Institute, International Water Management Institute (IWMI)

Read more about the projects.

This post was first published on the REACH website.

Macronutrient Cycles Programme draws to a close

The Royal Society hosts the finale of the £10.55 million Oxford-led research collaboration.

The Macronutrient Cycles Programme held its final workshop in June, drawing to a close the successful 5-year collaboration, led by Oxford University’s Professor Paul Whitehead and Dr Jill Crossman. The £10.55 million programme, funded by NERC, DEFRA and the Scottish Government, drew together expertise from 11 universities and 4 research institutes, to help better understand macronutrient cycles.

Over 110 researchers and stakeholders gathered at the Royal Society of London to hear the results of the research and implications for policy makers and catchment management stakeholders. The event featured an extensive stakeholder session including representation from DEFRA, the Environment Agency, Welsh Government, Scottish Government, River Trusts and Dr Ruth Kelman—Head of NERC’s freshwater sciences.

Macronutrient Cycles
Macronutrients – nitrogen (N), carbon (C) and phosphorus (P) – play pivotal role in the biogeochemical systems which sustain life. However, human activities, such as the burning of fossil fuels, food production and sewage discharges, have drastically altered macronutrient cycles, with significant implications for ecosystems and human health. Nitrogen and phosphorus cycles have accelerated globally by around 100% and 400% respectively on average.

Macronutrient Cycles Programme (MCP) sought to better understand these cycles, in particular to quantify the magnitude of nitrogen and phosphorus fluxes, their spatial and temporal variation, and how transformations occur through the catchment, in the context of a changing climate and perturbed carbon cycle. The term “catchment” was defined to address the exchange between the terrestrial, aquatic, atmospheric and estuarine systems. The programme sought not only to explore how these inter-related cycles limit ecosystems functions, but also and to examine what nutrient enrichment means for non-nutrient contaminants such as pathogens, and their impact up human health and biodiversity.

To realise this ambition the MCP funded the development of two innovative technologies, in addition to the following 4 projects:

1. LTLS: Analysis and simulation of the long-term/large-scale interactions of C, N and P in UK land, freshwater and atmosphere.
2. Turf2Surf: The multi-scale response of water quality, biodiversity and C sequestration to coupled macronutrient cycling from source to sea.
3. Quantifying annual cycles of macronutrient fluxes and net effect of transformations in an estuary: their responses to stochastic storm-driven events.
4. The role of lateral exchange in modulating the seaward flux of C, N, P.

Key Achievements

The research has contributed to long-term monitoring, providing great insight into how macronutrient sources have changed over the last 200 years. Data generated by the programme has helped improve modelling and aided the development of new models within the programme. These include a Bayesian model to further our understanding of seasonal variability and of how total fluxes of macronutrients respond to changes in river flow; a national scale model by developed to track the total leakage of phosphorus from water pipes; and two new catchment-scale models to address the effects of non-nutrient contaminants (pathogens and particulate organic pollutants).

In addition to modelling advances, the MCP supported the development of 2 innovative pieces of technology: a new ‘lab on a chip’ system for continuously monitoring nutrients in rivers and estuaries, and “Skyline 3D” a prototype system to remotely monitor greenhouse gases using a fly by wire remote gas collection system.

The MCP represents a major contribution to the current state of scientific knowledge of macronutrient cycles, which significant implications for environmental management. In total, the programme generated over 85 papers, and two special issue journals, with a third currently in press and expected to be published in the coming months.

Workshop presentations from the event will be available shortly on the Macronutrient Cycle Programme homepage. For further information about the programme contact Paul Whitehead – paul.whitehead@ouce.ox.ac.uk.

Sand dunes as giant rain gauges in the desert?

Reconstructing past precipitation fluctuations in dryland regions is challenging because of the nature of evidence left behind. Pore moisture within sand dunes provides a novel archive of palaeomoisture availability that has yet to be fully utilised. A recent review paper, led by Dr Abi Stone, outlines the status and future of this archive. Written with the late Mike Edmunds, the paper celebrates Mike’s great contribution to this area. Here, Abi reflects on their collaboration.


Rain gauge in the Kalahari. Picture by Abi Stone.

Understanding palaeoclimatic conditions in dryland regions is a key goal for climate science, particularly the responses of these environmentally sensitive regions at resolutions of decades to millennia. This allows the geosciences community to understand the nature of the response of drylands to factors that force the climate system, which enables better predictions of future dryland environmental change and variability. Arid and semi-arid regions make up around a third of the earth’s surface, are home to up to 2.1 billion people, and are areas particularly sensitive to future changes in precipitation and temperature.

However, reconstructing past rainfall trends and fluctuations in drylands is not an easy task. The negative moisture balance means that many of the pieces of evidence for precipitation (climatic proxies) used in other environments are not well preserved in drylands. For example, pollen does not survive in dry sediments and degrades on exposure to air. In addition, there are few records from calcium-carbonate deposits in caves (speleothems) found in more humid areas, such as those in China, that have notably produced impressive time-series of palaeoprecipitation and monsoon dynamics (in excess of 50,000 years).

This is because drylands often lack sufficient levels of precipitation for the speleothems to grow continuously. The distinctively dryland climate proxies of sand dunes and lake shorelines, such as those I cut my teeth on as a researcher during my DPhil, have their own shortfalls as palaeomoisture indicators. Their accumulation is mediated by a number of factors, of which changing moisture availability is just one.

Mike Edmunds was one of the pioneering researchers in the 1970s who discovered that the solute concentrations within the pore moisture of sediments above the water table (the unsaturated zone, USZ) were inversely correlated to rainfall amount. This work, based in Cyprus was followed by research in Senegal in the 1990s. By 2002, Mike had set out the potential of the unsaturated zone as a climate archive with Scott Tyler from the University of Nevada, Reno.

It was on a coach in 2013 driving around the chalk aquifer sites of Dorset, helping Mike to co-ordinate the introductory field-trip for Oxford’s Water Science, Policy and Management MSc class, that we got chatting about the current state of research into palaeoclimate using the USZ. After talking about our data from the Kalahari, I asked Mike if he thought it would be useful to write a review of the latest progress. He agreed in his usual enthusiastic manner and we started to plan the scope of the paper there and then.

We chose the journal Earth Science Reviews in order to try to bring this technique to the attention of the geoscience communities interested in palaeoclimatic reconstruction, but who may not spend so much time with their heads in the hydrogeological literature. Throughout the process of reviewing the literature and drafting the paper, I looked forward to my meetings with Mike, most often over coffee in my office of the time, at St John’s College. This looked out over St Giles and Mike was always a fan of watching the Oxford world go by. It was a contrast to the tranquillity of his own study which overlooked a wonderful garden at his home in Appleton, which he shared with Kathy.


Mike’s schematic, started in propelling pencil and meticulously completed in ink pen.

The main message of the paper is that yes, sand dunes do act as giant rain gauges in the desert. The length of that record depends on how big your sand dune is and how quickly the rainfall is trickling through it. Almost 40 studies worldwide have now used this approach to find out something about past climate. The schematic figure gives a summary explanation of how an USZ hydrostratigraphy accumulates. Mike revised an earlier conceptual diagram, sketching it using his trademark propelling pencil. Hydrostratigraphy is a fancy way of saying that the signal in the water in different layers of sand with increasing depth below the surface stores information about what climate was like when that water was near the surface in the past (and before it started soaking down through the sand)



Schematic with summary explanation.

I was in Namibia in May 2016 when the proofs of the final paper arrived for me to check. This was to collect more of the bright red-orange dune sand from the Kalahari above the Stampriet Artesian Basin, and investigate more about the nitrate Mike and I had uncovered a few years before. I had to explain the delay in checking the proofs. The reply had some tragicomedy attach to it, with the Global Journals Production Company (for Elsevier) asking if they could send the proofs to my co-author, rather than wait for my return. If only! I can only guess that they also found it hard to believe that he was gone.



Sampling sand dunes in the Kalahari desert. Picture by Abi Stone.

In the paper we draw global examples together to highlight that hydrostratigraphies are useful for three timescales (duration and resolution):
(i) centennial-length, decadal resolution: records of past rainfall and moisture availability and useful to identify how land-use change modifies rates of water infiltration, such as in irrigated parts of the Thar Desert, India.
(ii) millennial-length, decadal resolution: most notably in the Badain Jaran Desert in China, where the record spans 2,000 years, demonstrating the same climatic shifts recorded in tree-rings and even written historical documents from former Chinese dynasties.
(iii) multi-millennial length, low-resolution records, such as in Nevada in the United States, where the shift from wetter to arid conditions occurred before the start of the Holocene (~11,700 years ago).

You can read more in Stone, A. E. C., Edmunds, W. M. (2016) Unsaturated zone hydrostratigraphies: a novel archive of past climates in dryland continental regions. Earth Science Reviews 157, 121-144.

Oxford University and the British Geological Survey will host the first W. Mike Edmunds Memorial Lecture at Christ Church on 3 November 2016. For further details visit the online booking page.