Jochen BUNDSCHUH
National Centre for Engineering in Agriculture University of Southern Queensland
Faculty of Engineering and Surveying West Street
Toowoomba QLD 4350, Australia Jochen.Bundschuh@usq.edu.au
Technika Poszukiwañ Geologicznych Geotermia, Zrównowa¿ony Rozwój nr 1/2012
PORTFOLIO AND PhD OPPORTUNITIES FROM USQ GROUNDWATER RESEARCH GROUP*
Part I
USQ Groundwater Research Group, which presently has 26 members, was established in 2012 under the University funded Sustainable Regions Initiative. The total committed USQ investment in the Group to date is more than $1.3 million. Our group is currently managed within the National Centre for Engineering in Agriculture (NCEA) with members also drawn from the Faculty of Engineering and Surveying and Faculty of Sciences and four USQ research centres which allows a truly interdisciplinary integral approach for providing solutions to complex problems. The group works closely with the existing Irrigation and Natural Resources research team within the NCEA, with the Water Management research group within the USQ Australian Centre for Sustainable Catchments, with the Computa- tional Engineering and Science Research Centre and with the Australian Centre for Sus- tainable Business and Development. The USQ Hydrogeology Group is led by author:
Professor Jochen Bundschuh who is an internationally recognised expert with over 20 years of experience in contaminant geochemistry and hydrogeology.
The vision of the group is an economically profitable but sustainable exploitation of groundwater and other natural resources. This includes protection of aquifers; remediation of contaminated aquifers, sediments and other geoenvironments; remediation and reclamation of contaminated sites; sustainable waste and energy storage underground; production of freshwater including treatment and desalination; and geothermal energy exploration and exploitation. Therefore, processes in and interactions between different geoenvironments such as soils, sediments, vadose zone, and aquifers are dealt with in a holistic integral approach.
* License for publication granted to Technika Poszukiwa Geologicznych, Geotermia Zrównowa¿ony Rozwój.
Copyright remains with the author.
KEY RESEARCH THEMES INCLUDE – Field studies in the farm – catchment – region scale,
– Numerical modelling of fluid flow, contaminant transport, geochemical evolution and heat transport in dynamic soil, vadose zone and aquifer systems,
– Geochemical applications for assessment of contamination contamination risk; protec- tion of water resources; remediation/restauration of contaminated sites; water treatment;
freshwater production.
Our multi- and interdisciplinary research group performs state-of-the-art research of international reputation on geoenvironments as well as sustainable combined water-energy solutions. We are working globally. We offer PhD opportunities all over the world, in your home country as well as in Australia itself. We are currently searching highly qualified and motivated PhD students. Potential topics, whose implementation further may depend on funding opportunities, may be but are not limited within the following wider areas. We welcome your own research proposals for discussing.
Topic 1: Groundwater for Sustainable Development – Groundwater Assessment and Integrated Management
Topic 2: Numerical Modelling of Groundwater Systems – Simulation of Groundwater Flow, Contaminant and Heat Transport in Aquifers and vadose Zone
Topic 3: Geochemical Modelling of Aquifers Topic 4: Arsenic in the Environment
Topic 5: Low Enthalpy Geothermal Resources – Opportunities for Developing/Tran- sition Countries
Topic 6: Freshwater Production and Water Treatment by Renewable Energy Appli- cations
Topic 7: Sustainable Energy Solutions in Agriculture Topic 8: Geothermal Energy from Underground Mines Topic 9: Geothermal Energy from Oil and Gas Wells
Topic 10: Freshwater Production using geothermal Heat (groundwater, residual water, seawater)
Topic 11: Water Treatment using geological Materials: Sustainable Options for rural and urban isolated Areas
Topic 12: Water Treatment using Constructed Wetlands (Phytoremediation) Topic 13: In-situ Remediation of deep Aquifers
Topic 14: Bioremediation of contaminated Water, Soils, Sediments, Sludges and Mining Residuals
Topic 15: Risk Assessment of Heavy Metals and Arsenic and from Mining: Under- standing Mobilization, Bioavailability, and Remediation Options
Topic 16: Geothermal Arsenic
Topic 17: Geomicrobiology of toxic Trace Elements in aquatic Ecosystems Topic 18: Fluoride Transport and Mobility Controls in Sedimentary Aquifers
Topic 19: Geology – related Ecotourism for Sustainable Development Topic 20: Climate Change Impact on Groundwater Resources Topic 21: Uranium in Groundwater and other Geoenvironments
Topic 22: Water Quality and Livestock Health and Production: Biotransfer of geogenic Toxins from Groundwater to Livestock
Topic 23: Livestock impact on Water Resources and Sustainable Solutions Topic 24: Geothermal Heat for Livestock farming, Fish and Shellfish Cultivation Topic 25: Ecosystem Restoration and Monitoring of Areas Impacted by Mining Activities Topic 26: Coal Seam Gas Exploitation and Underground Coal Gasification: Environ- mental Impacts and Sustainable Solutions
Topic 1: Groundwater for Sustainable Development – Groundwater Assessment and Integrated Management
Groundwater is often the primary source for domestic and industrial water supply, and support the major demand for agriculture by providing large quantities of irrigation water, especially in zones with rather dry climate where crop production without irrigation is not possible. It plays a key role in keeping wet ecosystems sustainable, and often also main- taining a suitable environment for human settlements. All over the world groundwater is an extremely important natural resource, more important than most people realize. Especially significant is the need to manage effectively their own water resources while modernising and integrating their economies. Such water resources management requires considerable technical expertise in hydrogeology.
The research area “Groundwater for Sustainable Development” is an inter- and multi- disciplinary research field linking groundwater resources with human society. This research covers all fields of groundwater from its origin in aquifers, water movement and exploitation of aquifers, sources and pathways of contaminants and their introduction in the food chain up to the uptake by humans. Objectives of the research are to facilitate (i) to improve our understanding of groundwater resources and to advocate their effective and sustainable management and protection against contamination (ii) the improvement of effective and sustainable management of water resources, and (iii) the improvement of human access to groundwater resources in adequate quantity and good quality, the meeting of the increasing demand for drinking water, and irrigation water needed for food security to contribute to a social and economically sound human development.
Principal topics for postgraduate research in this area are:
– Assessment of groundwater resources (quantity & quality),
– Hydrogeologic systems and sustainable groundwater resources management, – Groundwater contamination and protection,
– Groundwater vulnerability and risk assessment,
– Chemical processes. Sources and mobility of contaminants (natural, anthropogenic, inorganic, organic),
– Groundwater chemistry and geochemistry; water-rock exchange processes; multiphase flow and multispecies transport (inorganic/organic substances); contaminant transport, – Groundwater quality and food safety,
– Epidemiology and public health impacts of groundwater contamination,
– Groundwater treatment and remediation (insitu, ex-situ; chemical, microbiological, etc.), – Groundwater recharge assessment,
– Assessing impact of climate change on groundwater resources, – Interactions between surface water, deep, and shallow aquifers, – Geobiochemical and biological processes in aquifers,
– Water supply and demand scenarios,
– Transport of fluids (water, organic phases, gases, etc.), solutes and heat,
– Interactions between geosphere, hydrosphere and biosphere; bioavailability and bio- accessibility of toxins; contaminant ecotoxicity,
– Biogeochemical/geomicrobial processes, i.e. interaction between microbes and mine- rals/solutes; microbial catalysis of chemical reactions; microbial contaminant mobili- zation and sequestration,
– Environmental impact assessment,
– Assessment of impacts on geoenvironmental systems (contaminated land environments, leakage of petroleum storage tanks; contamination of soil, sediments, mining residuals/de- posits, vadose zone, and aquifers),
– Ecotoxicity evaluation (e.g. mining sites), – Groundwater and mining.
Topic 2: Numerical Modelling of Groundwater Systems – Simulation of Groundwater Flow, Contaminant and Heat Transport in Aquifers and vadose Zone
Numerical modelling of fluid flow in saturated groundwater-flow systems and the vadose zone, and the solute and heat transport has many practical applications. Real subsurface systems, such as aquifers and the vadose zone are complex systems, in which numerous interfering parameters and parameter functions drive the water movement and the transport Our project area Chianan Plain in SW Taiwan: Instalation of multilevel piezometers in Beimen township for monitoring groundwater level and goundwater chemistry in different subaquifers.
of solutes (e.g. contaminants), gases, and heat. With exception of very special cases, these transport processes are coupled, and as consequence can be only described using numerical methods. Hence numerical modelling is an essential stateof-the art tool for the analysis of aquifer systems in general and to solve special problems regarding flow and contamination of water in the aquifer and the unsaturated zone.
A numerical model, of a real subsurface system can be used to describe its behaviour caused by inner and outer impacts on it. Simulations can be used for forecasts, where the impacts of different measures (e.g. a certain water or energy withdrawal or contaminant input) can be simulated for the past and forecasted (e.g. changes of the groundwater level, changes of groundwater quality, propagation of contaminant fronts, changes of temperature).
Groundwater flow simulation can be applied to determine groundwater recharge and recovery, where the consequence of the groundwater withdrawal through wells, horizontal wells of filter galleries on the natural groundwater flow field (e.g. decrease of the ground- water table or pressure) can be simulated and used to determine which is the optimal type and location of withdrawal installation (group of wells and location of the single wells in it, horizontal well, filter gallery), and respective withdrawal rate(s). Beneath that use for groundwater management tasks, groundwater flow simulation can further used for many applications as to simulate well hydraulics and thewater or energy withdrawal or contaminant input) can be simulated for the past and forecasted (e.g. changes of the groundwater level, changes of groundwater quality, propagation of contaminant fronts, changes of temperature).
Groundwater flow simulation can be applied to determine groundwater recharge and re- Drilling and sampling of sediment cores in our project area in India: The boreholes were drilled in Moyna and Ardebok villages located in Barasat, West Bengal. Core sediments were collected using the split-spoon sampler with rotary drill rigs at various depths up to 70 m. Groundwater samples were collected from the nested piezometers at different depths from the borehole sites.
covery, where the consequence of the groundwater withdrawal through wells, horizontal wells of filter galleries on the natural groundwater flow field (e.g. decrease of the ground- water table or pressure) can be simulated and used to determine which is the optimal type and location of withdrawal installation (group of wells and location of the single wells in it, horizontal well, filter gallery), and respective withdrawal rate(s). Beneath that use for groundwater management tasks, groundwater flow simulation can further used for many applications as to simulate well hydraulics and the evaluation of pumping and infiltration tests to determine aquifer parameters. Other application areas are in civil engineering for example for designing a proper drainage in excavation pits, open mines, and to determine water influx in tunnel constructions or underground mines. In hydroelectric projects, the simulation of water percolation through, below, and around storage dams, are important applications, since they can be used to design proper measures to reduce the respective flow rates, e.g. by liners, injections. Additionally the filling of storage lake and the impact on natural groundwater flow field can be simulated. Another important application is the simulation of saltwater intrusions, e.g. by seawater flowing into freshwater aquifers. Mo- delling water flow between different aquifers is another application which is important when evaluating aquifer vulnerability.
Flow simulation can be coupled with solute transport simulation and may be applied to model natural or anthropogenic induced chemical species (e.g. contaminant) transport including processes of solute sorption, production and decay. Such simulation may be applied to analyse groundwater contaminant transport problems, to analyse contamination hazard and risk, to define aquifer remediation measures in case of a contamination, and to delimit groundwater protection zones around groundwater capture zones as for example water works or other water capture zones. Numerical transport modelling can be further applied for the analysis of problems such as those related to (i) subsurface-waste injection, (ii) landfill leaching, and the evaluation of tracer tests. Flow simulation as well as solute Groundwater balances from scenario modelling in our project area Salta, Argentina. Modelling groundwater flow in a 2 layer aquifer with impermeable clay layers (grey) without (left) and with (right) groundwater withdrawal from the deeper layer. The arrows indicate the mass balances of the groundwater flowing through the different layers towards the right model margin.
transport can be combined with heat transport simulation and can be used for the analysis of problems such as those related to (i) radioactive-waste disposal, (ii) subsurface energy storage, (iii) hot-water geothermal systems, (iv) steam dominated geothermal systems.
Topic 3: Geochemical Modelling of Aquifers
Geochemical modelling can be applied to a diversity of subsurface systems from close to the Earth's surface, down to deep-seated geothermal reservoirs. Geochemical modelling is an important tool in environmental studies, and in the areas of subsurface and surface hydro- logy, pedology, water resources management, mining geology, geothermics, hydrocarbon geology, and related areas dealing with the exploration and extraction of natural resources and the protection and management of our freshwaters and our environment. Geochemical modelling simulates the chemical and physical processes affecting the distribution of chemi- cal species in liquid, gas, and solid phases. The reactions and processes, and their coupled interactions, are dependent on a number of environmental variables (e.g. temperature, pressure, ionic strength), and are also affected by the dynamics of matter and energy flows, including fluid, solute and heat flow.
Research areas comprise mathematical modelling of geochemical and groundwater processes, from the shallow vadose zone to deep geothermal systems. Computational me- thods simulate chemical reaction processes in low- and high-temperature aqueous systems such as groundwater, petroleum and geothermal systems. They consider homogeneous and heterogeneous chemical reactions, including their kinetic simulation for the calculation of species concentrations, as well as fluid heat, and reactive solute transport, Different types of geochemical models are used such as: speciation, reactionpath or forward, inverse- and reactive-transport models.
Interesting applications (but not limited to) of geochemical models in different scientific areas and environmental settings are:
– Contaminant transport in geoenvironments, – Geoenvironmental impact studies,
– Inverse and forward modelling of heavy metal transport in an aquifers,
Mesh of southern Loz Azufres geothermal reservoir (left) and comparison of modelled pressures using single, double and triple porosity models (from our book: Introduction to the Numerical Modeling of Groundwater and Geothermal Systems, 2010, CRC Press).
– Geochemical modelling of water chemistry evolution along groundwater flow paths, – Modelling of reactive solute transport at sites contaminated by petroleum hydrocarbons, – Modelling for assessment of natural remediation of phosphorus in soils,
– Assessment of impacts on geoenvironmental systems (contaminated land environments, leakage of petroleum storage tanks; contamination of soil, sediments, mining resi- duals/deposits, vadose zone, and aquifers),
– Ecotoxicity evaluation (e.g. mining sites),
– Remediation/reclamation of contaminated sites (e.g. mining sites), – Waste water injection underground.
Topic 4: Arsenic in the Environment
Although arsenic is known as 'silent toxin' since ancient time, and the contamination of drinking water resources by geogenic arsenic was described from different places around the world long ago – as e.g. in Argentina in 1917 – it was not before two decades ago, that it received overwhelming public attention worldwide. As a consequence of the biggest arsenic calamity in the world was detected two decades ago in Southeast Asia, there has been an then arsenic contamination in drinking water resources, soils, plants and air of predominantly geogenic origin, the propagation of arsenic in the food chain, the chronic affects of arsenic ingestion by humans, and their toxicological and related public health consequences, were described in many parts of the world, and every year new countries or regions are discovered, where the arsenic problem was not known so far.
The importance of the topic of arsenic in the environment can be recognized from the fact that worldwide more than 200 million people currently suffer from either arsenic conta- mination of water resources and food. Our recent compilation suggests the incidence of arsenic contamination of drinking and irrigation water has also doubled in the last ten years Electron microprobe analysis of weathered volcanic glass with fluidal structure - from our study area of Santiao del Estero, Argentina.
with reports of contamination from over 75 countries, including Australia. Hence, arsenic is an increasing global problem which will require global solutions. Research into the occu- rrence, mobility and bioavailability of arsenic in different environments including aquifers, soils, sediments as well as the food chain, will all be increasingly important.
The presence of arsenic is found in several regions distributed all around the world, both in developing and industrialized countries; although mitigating the problem is quite different in both, related to the different economic and social conditions in both country groups (fig.
1). Considering high concentrations of As in the drinking water only, it has been estimated that 200 million people worldwide are at risk; a number which is expected to further increase due to the recent lowering of the limits of arsenic concentration in drinking water to actually 10mg/l, as it was already adopted by many countries, and considerations for even further decreasing this value.
We are performing inter- and multidisciplinary research on arsenic for the last two decades, making an effort to link the occurrence of geogenic arsenic in different environ- ments and the potential contamination of ground- and surface water, soil and air and their effect on the human society. This state-of-the art research fulfils the growing global interest on the arsenic issue worldwide which is going alongside with stronger regulations of arsenic contents in drinking water and food, which were and are adapted not only by the indu- strialized countries, but increasingly by developing countries. PhD research areas cover all fields of research concerning arsenic in the environment with an aim to present an integrated approach from its occurrence in rocks and their mobilization into the ground- and surface water, soil and air, its transport therein, the pathways of arsenic and their introduction into the food chain up to the uptake by humans. Human arsenic exposure, bioavailability, metabolism and toxicology are treated together with related public health effects and risk assessments in order to better manage the contaminated land and aquatic environments to reduce human arsenic exposure. Arsenic removal technologies and other methodologies to mitigate the arsenic problem are addressed not only from the technological, but also from economic and social point of view. We aim such inter- and multidisciplinary approaches, since only they Authors 2011 compilation of world distribution of aquifers and surface water bodies with high concentrations of dissolved geogenic arsenic with over 270 outlined areas affected.
allow case-specific selection of optimal mitigation measures of each specific arsenic problem mitigate the problem and provide the population arsenic safe drinking water, food, and air.
Research group has an ambition to make international, multi- and interdisciplinary state-of-the-art arsenic research oriented to the direct solution of problems with considerable social impact and relevance rather than only focusing on cutting edge and breakthrough research in physical, chemical, toxicological, medical and other specific issues on arsenic on a broader environmental realm. We also have task and role to increase awareness and knowledge among administrators, policy makers and company executives, on the problem and to improve the international and bilateral cooperation on the arsenic contamination and its effects globally. The fact that I am led international organiser of the congress series
"Arsenic in the Environment" and led editor of the homonymous book series commissioned by CRC Press attributes world-class reputation to our research.
Topic 5: Low Enthalpy Geothermal Resources – Opportunities for Developing/
Transition Countries
Low-enthalpy geothermal resources can become a driving force for an economical sound sustainable development for many developing and transition countries. This widely available, domestic and environmental-friendly energy sources can provide energy for in the framework of sustainable energy development for power generation, rural electrification and direct use to support small scale industries, like food processing, green house cultivation, pisciculture etc., and balneology and tourism.
In many developing countries the exponentially growing electricity demand can be covered by using locally available, sustainable low-enthalpy geothermal resources (80–150°C). Such low-enthalpy sources can make electricity generation of many countries more independent from oil imports or from the over-dependence of hydropower. In contrast to the high-enthalpy geothermal resources (>150 °C), which are mostly restricted to active Arsenic in the groundwater of Huhhot Alluvial Basin of Inner Mongolia: Aquifer geochemistry in the shallow aquifers and implications on the mobilisation of arsenic. The figure in the middle shows the redox classification of the groundwater. Right: Health impacts on a resident due to arsenic, which is in high concentrations present in the arsenic (III) species, in drinking water.
volcanic zones, the low-enthalpy resources cover much more widespread and are found in most countries of the developing world. Till now this huge energy source has not been exploited by the developing countries in a commercial way for electricity generation. Until now, they are only used by some developed counties like US, Iceland, and New Zealand for commercial electricity generation. The reason why low-enthalpy geothermal resources are not used for electricity generation is the fact that there is still a misbelief that low enthalpy thermal fluids are fit only for direct application. This myth is removed from the minds of developing countries with the advancement of drilling technology, development of efficient heat exchangers and deployment of high sensitive binary fluids.
The opportunities for commercial electricity generation from low-enthalpy geothermal resources in developing countries must be seen under different aspects: (i) Costs will decrease compared to high-enthalpy geothermal resources and to conventional energy, (ii) technological development in binary fluid method- like introduction of Kalina cycle and significant cost reduction resulting from this technique, (iii) all the developing and developed countries are compelled to reduce carbon emission; this can be overcome either by carbon trade or develop alternate sources to supplement the loss incurred due to reduction in coal consumption.
Our research area addresses the low-enthalpy geothermal resources available around the world and their possible uses as function of temperature and economical availability, suitable geothermal exploration techniques, and optimal geothermal exploitation methods. Environ- mental aspects and benefits of geothermal energy resources utilization and related reductions of greenhouse and other gases are thereby targeted in the frame of local environmental protection, and as cost-effective climate change opportunity in the frame of global climate and international climate policies. We aim that our research outputs provide information for decision makers to overcome institutional, policy regulation and financial obstacles which hinder the promotion of geothermal energy in many countries. We aim to provide them solid scientific background information and showcasing ways helping them overcoming these barriers by providing regulatory legal, institutional and political frameworks, calling for international support for capacity building and awareness formation for popularisation of geothermal energy, including incentives to facilitate private sector investments and policy reforms that can aid sustainable energy development. Our research focuses on all aspects of low enthalpy geothermal thermal fluids with the aim to assist developing countries rich in such thermal resources, and agencies for bilateral and international cooperation, to explore and exploit these domestic energy resources for electricity generation as well as direct heat use in agriculture, industry and for space heating/cooling. Our PhD opportunities in this area are ideal if you approach to become in future a leading energy decision maker, energy sector representative and administrator, policy maker from the governments, business leader, power producer, energy engineer/scientist, academic, or hydrogeologist, water resources manager and engineer, land planner or agronomist, who is concerned about the energy related problems of your country or an expert involved in international technical and economic cooperation and assistance with developing countries including regional or inter-
national developing banks, aid institutions, donors, etc. Our visualisation of present and future CO2 emissions from electricity production in the non-OECD regions. The figure proves the exponential increase of future CO2emissions which should convince any denier of global climate change. The figure highlights the urgent need of governments for energy reforms replacing fossil fuels by renewable energy and improving energy efficiency.
Emission values are calculated from electricity generation and source mix data (data: EIA 2007) and average CO2emission values (Kasameyer 1997) for coal, oil, and gas fired power plants.
Topic 6: Freshwater Production and Water Treatment by Renewable Energy Applications
Worldwide, many regions have a great potential to cover part of their pressing water needs by renewable energy powered water treatment processes using either thermal or membrane based technologies. Not only arid and semiarid regions are increasingly exposed to water shortage but also many other regions face a limitation of freshwater resources either by increasing contamination of surface water bodies and/or groundwater resources unsui- table for drinking and irrigation purposes either due to their high grade of mineralization or their contents of toxic components as e.g. fluoride and arsenic; the last affecting worldwide the drinking water of over 200 million of people in over 70 countries. In many areas without centralized water supply, treatment techniques using locally available renewable energy resources such as wind, solar and geothermal can provide an economic, social and environ- mentally sustainable option for clean water production.
Visit to Yangbajing geothermal field in Tibet. The geothermal low- and high enthalpy hydrothermal resources available in the Autonomous Province of Tibet could provide the entire energy demand of the region.
Renewable energy used for freshwater production by desalination can provide important options for the agricultural sector. In inland areas, wind, solar, geothermal, and biomass can be used as energy source to desalinate brackish or saline groundwater, which is found at many places; further residual communal and industrial wastewater can be made usable again through desalination. Freshwater production powered by renewable energy resources is not only an option for areas where decentralized solutions are demanded. They can also provide economically sound and environmentally friendly options for desalination along the coast- line. These areas are where often densely populated and where natural freshwater resources are not enough to cover the recent or future demand.
Our research, which is in close cooperation with industry targets possible cost-efficient techniques and application opportunities for different scales and local conditions regarding water type and available renewable energy resources which to assess are primary focus of our research. We further evaluate costs of novel treatment units using renewable energy sources and compare them with those of other technologies for clean water production considering external costs, such as environmental and social costs which are caused by using fossil fuel based technologies. Additionally of key interest is energy efficiency since it is of special importance in systems that are to be powered by renewable energy. Moreover applications of water supply systems providing water in emergency condition are a challenging topic of our group.
Photo of a solar/wind powered water treatment unit in Zanzibar installed after joint R&D with a private company in 2011. The reverse osmosis unit uses energy recovery system, produces 2400 L/day of deinking water and consumes 4 kWh/m3produced drinking water. Photo: J. Hoinkis.
Research focuses on but is not limited to the following key areas:
I) Direct heat applications for desalination – passive solar distillation
– solar based humidification/dehumidification processes – geothermal heat for membrane distillation
II) Desalination through electricity
– photovoltaic-, wind-, or geothermal-powered reverse osmosis, electrodialysis and other membrane-based systems
– wind mechanical vapour compression systems III) Water treatment through direct solar heat use
– solar disinfection (heterogeneous photocatalysis, Fenton and photo-Fenton processes) – solar assisted water decontamination.
These challenging topics fulfil the urgent and pressing need to provide more sustainable solutions for the energy-intensive industry of desalination of seawater, saline groundwater and municipal/industrial waste water by using sustainable, environmental friendly, rene- wable energy sources and energy efficient technologies for freshwater production which is permanently expanding due to the permanently increasing freshwater demand for drinking, irrigation and other purposes. This approach counts for the fact that future energy provision, freshwater supply and global climate change mitigation are intrinsically linked issues and key challenges for modern society.
Conceptual model of irrigation simulation with initial and boundary conditions (Bundschuh &
Hoinkis 2012).
Topic 7: Sustainable Energy Solutions in Agriculture
This importance of this inter- and multidisciplinary research area is reflected by the fact that increasing uses of energy resources are one of the major challenges facing agriculture. Con- tinuous high fossil fuel price and the needs for “green food” and significant reduction in the greenhouse gas emissions make the improvement of farming energy efficiency as well as an increased use of energy from renewable sources such as biomass, solar, wind and geothermal essential. Rational and efficient use of energy resources together with the exploration of new alternative and renewable energy sources are essential for sustainable development in agriculture.
This research area is focused on effective energy use and renewable energy powered technologies to fulfil future needs of a modern sustainable agriculture. Our group aims to provide a technological and scientific endeavour to assist society and farming communities in different regions and scales to improve their productivity and sustainability. This is done through providing the latest technology and cost-efficient techniques and by deepening the understanding of possible sustainable energy sources available on-site and application opportunities for different scales and situations. Resources and costs of different sustainable energy sources, preferably renewables, and novel technologies are investigated, developed, evaluated and compared with those of other classical technologies for agricultural pro- duction, taking into account environmental and social costs that are caused by using fossil fuel based technologies. Energy efficiency is another key interest since it is of special importance in the systems. Also, applications of new and improved technologies are de- veloped and promoted. Such research is timely due to worldwide interest in sustainable agriculture and the continually increasing demand for food and fibre in an economically sustainable way, while contributing to global climate change mitigation.
The research field includes critical and new areas of research on challenging issues in novel technologies and their applicability in agriculture and associated primary industries. It focuses on but is not limited to the following key areas:
– Energy use and efficiency in agriculture and its supply chains, – Energy monitoring and analyses,
– Energy and water,
– Environmental impact of energy use,
– Geothermal/solar heat for soil heating, aquaculture and glasshouses, – Geothermal/solar heat for freshwater production,
– Clean production and sustainability of agriculture, – Alternative agriculture and intensive agriculture, – New and emerging technologies,
– Energy supply and alternative and renewable energy, – Renewable energy sources for agriculture,
– Life Cycle Assessment, greenhouse gas emissions and carbon footprints.
These topics fulfil the urgent and pressing need to provide innovative, effective and more sustainable solutions for agriculture by using sustainable, environmental friendly, renewable
energy sources and energy efficient technologies for agricultural production which is important to feed the rapidly growing world population and to overcome major challenges such as the reduced availability of water, energy and agricultural land.
Topic 8: Geothermal Energy from Underground Mines
The mining industry has left thousands of flooded underground mines worldwide. The construction of these mines was extremely costly. To better make use of these huge investments even after closure of the mine, the generation of geothermal energy from these man-made geothermal reservoirs is in many cases an economic and environment-sound solution. Hence, instead of being left as empty holes in the underground, the closed mines can become sources of low-enthalpy geothermal energy for the local community which involves further a high social benefit. So for example closed coal mines could once again generate energy, not from coal, but from hot water reservoirs. Further such use of sustainable renewable energy can provide additional income for the mining company and improve a mining company's public image. The last is of particular importance since in many cases abandoned mines pose chronic contamination and safety problems so that it is a better option for the companies to evaluate the suitability of converting their flooded mines into a source of clean renewable geothermal energy. Many of the mines are naturally flooded after their closure and the temperature of this water is high enough to be used for geothermal direct heat Greenhouse in Argentina heated with geothermal water (photo: Abel Pesce).
applications. Due to minimum drilling needs this is also a very cost-effective option com- pared to drilling geothermal wells or use fossil fuel resources. This green and renewable energy is particularly suitable to be extracted with geothermal recovery loops coupled to heat pumps and can be used for residential and commercial heating requirements through an existing or new district heating network. Geothermal energy from closed mines is also interesting for nearby active mines where it can be used cooling of mine workings. Other applications are in the agriculture and for heat supply for industrial processes as well as in the sector of recreation. Based on continuously increasing prices and price instability for fossil fuels, and the focus on energy independence of countries, mine water used as geothermal resources could significantly reduce the costs compared to conventional energy sources.
Until now, geothermal energy from underground mines in general has been overlooked as a possible domestic and clean energy source. However, there are already a small number of case studies of existing and proposed installations from around the world in particular from Canada, USA, UK, France, Germany, The Netherlands, Poland, Spain, Slovakia and Ukra- ine, India, and South Africa. A well advanced successful example is from the Netherlands where at the town of Heerlen a closed coal mine has been recently converted into a source of geothermal energy to power a large-scale district heating system supplying 350 homes and businesses with hot water and heating in the winter.
Our group focuses on discussing the energy and economic potentials of these resources considering respective site-specific geological, hydrogeological, and technical conditions of mining fields, which vary widely, depending on type of mine (e.g. coal, lead, gold, copper, diamond mines), volumes of void space for water, design, and depth. Further, technical issues of exploitation and heat use are to be adapted to the site-specific different geological settings and different heat applications, together with considering the respective economical, regulatory, environmental and social issues.
Topic 9: Geothermal Energy from Oil and Gas Wells
World-wide there have been millions of oil and gas wells, many drilled to deep zones where temperatures and pressures are high, often producing hot water together with hy- drocarbons. The extraction of heat from these wells and conversion to electricity can be done using proven state-of-art technology, which has been available for several years. Wells in operation for oil and gas extraction as well as abandoned oil and gas wells can be used for a reliably commercial on-site electric power generation, particularly from heavy flow rates of hot water having temperatures exceeding 100°C. Currently, the hot water in oilfields is wasted and either hauled away or re-injected at material costs. Until recently, production wells, abandoned wells and hydrocarbon reservoirs in general have been overlooked as possible geothermal energy sources. Our research focuses on the geothermal potential of hydrocarbon reservoirs, targeting areas and fields containing operational metrics supporting geothermal energy. We look on the design differences between hydrocarbon and geothermal wells as well as the different stimulation methods used in hydrocarbon and geothermal
energy exploitation to increase permeability and porosity if the corresponding natural values are too low. We evaluate the method, which is the most suitable for specific site-dependent geological and other frameworks, for heat extraction and electric energy generation from hydrocarbon wells. Our group focuses how geothermal energy of hydrocarbon reservoirs can be produced: (i) In wells with current oil and gas exploitation where coproduced hot water can be used to generate electricity; (ii) In oil and gas wells that can become a source for commercial geothermal electricity production and a huge commercial opportunity; (iii) In offshore applications helping to solve the problems of disposal of oil platforms, and using them for extraction of geothermal energy; and (iv) Drilling new geothermal wells in promising hydrocarbon fields having subsurface data available from the oil and gas drilling operations. All these options are researched in the context of geological setting, technical demands, feasibility, scale and costs.
Topic 10: Freshwater Production using geothermal Heat (groundwater, residual water, seawater)
For most countries, water, energy and climate protection are the most important challenges. Many rural regions have a common problem that hinders the social and economic development. They lack of an economically affordable access to safe freshwater and energy.
Especially concerned are decentralized off-grid areas. An electric grid connection or the use of diesel-powered generators is economically not sustainable and/or not affordable and not environmental friendly. Water from groundwater which often is the only natural water source Our research in southern Mexicans oilfields: In the southern coast of the Gulf of Mexico
hydrocarbon reservoirs are associated with deep geothermal aquifers. Some of their wells are invaded by geothermal brine, producing a variable mixture of hot water and oil. This water, at temperatures of 140–170°C and a density of 1150 kg/m3, flows vertically through a fault in the aquifer located at a depth of 6000 m.
for the entire year is often brackish/saline or it is contaminated by natural or anthropogenic contaminants.
Water and energy are not independent commodities. Renewable energy sources can be used for production of clean freshwater for drinking, agriculture and other purposes. We all know that we can generate vast amounts of freshwater if we had access to unlimited amounts of cheap energy. Unfortunately, energy from fossil fuel sources is scarce and is getting continuously scarcer and therefore more expensive and less affordable. Also, fossil fuel combustion is increasingly blamed as it contributes to global warming. The increasing need for climate protection places further constraints on the allowable solution space and zero emission solutions are required.
Reverse osmosis is popular for water desalination but only 40% of the world's desalinated water comes from reverse osmosis plants. About 50% is produced by thermal desalination.
Thermal desalination is preferred wherever there is access to cheap heat such as geothermal.
Geothermal heat can provide freshwater by economically sound zero emission desa- lination technology for small homesteads, cattle stations, small communities, the agricultural sector, isolated mining sites and tourist complexes. In inland areas, geothermal heat can be used as energy source to desalinate brackish or saline groundwater, which is found at many places; further residual communal and industrial wastewater can be made usable again through desalination. It allows sustainable water supply and waste water treatment for small communities. It allows industries, where mining and hydrocarbon industries are especially important, to treat their water in an economic and environmental sustainable way.
Geothermal desalination/treatment allows the removal of geogenic contaminants such as fluoride and arsenic; the last affects groundwater resources in more than 70 countries and is a health concern of at least 200 million people there living in rural areas depending on arsenic contaminated well water. Additionally geothermal heat can be used for greenhouse de- Principle of membrane destillation using geothermal heat. Left of the mebrane ist the
brackish/saline water to be treated, to the right the pure drinking water. Minimum temperature of geothermal water is about 60°C (http://www.purity.se)
salination and to reduce grade of mineralization of irrigation drainage water down to levels, which authorities set for being released into rivers. This contributes to rural development and climate protection. However, freshwater production powered by geothermal heat is not only an option for areas where decentralized solutions are demanded. They can also provide economically sound and environmentally friendly options on-grid areas and for seawater desalination along coastlines.
Fortunately, many regions, count on vast, locally available low-enthalpy geothermal resources, which are a renewable zero-emission therefore climate protecting energy source.
Their fluids are often not hot enough to generate economically electricity but still enough warm to use the heat for desalination of water to either reduce its mineralisation or remove con- taminants. There are different technology options developed for using heat from other sources that can be adapted through innovative research for using geothermal heat for freshwater production, which are relevant to the specific site conditions in the respective area. These distillation processes include multistage flash (MSF), multiple-effect distillation (MED), humidification-dehumidification (H-DH), thermal vapour compression (TVC) and membrane distillation, which is the only membrane technology which can be driven directly by heat.
Our group evaluates the potentials of low-enthalpy geothermal resources in respect to their suitability to provide heat for desalination based on results of existing research or where not existing through own research. This information is base for choosing and adapting desalination techniques to the specific site conditions. The selection of the most appropriate technological solutions of geothermal heat use for freshwater production is essential. Our group evaluates the local site-specific geological, hydrochemical, geothermal, economic, financial, and socio-cultural conditions as these are crucial for choosing the optimal tech- nology and design for geothermal desalination. An important target of our group is the design of an environmentally friendly and economic sound discharge of the brine which is a waste product into suitable aquifers or other disposal. These techniques have not yet been studied in detail and research forms a challenging goal for some type of brines such as arsenic-rich brine streams. State-of-the-art of hydrogeological and hydrochemical aspects must thereby be considered for different components. Unlike in standard seawater desalination (seawater has basically uniform water quality), the treatment of groundwater and residual waters requires a deeper understanding of the source water composition and its implications on the respective treatment process.
Wind and solar powered desalination units have proven technical and economic viability for freshwater production in off-grid areas. Desalination using geothermal energy which has the enormous advantage that, in contrast to wind and sun, provides a stable energy supply, which is available 24 hours a day all through the year so that thermal storage is avoided, needs significant R&D to further optimize technologies regarding efficiency by developing smart grid systems and reduce costs. So far it is only developed on laboratory scale. To change that situation is a goal of our group.
The expected outcomes from this interdisciplinary research will be useful for many authorities and companies seeking solutions to effectively use geothermal heat for providing
freshwater from brackish or saline groundwater in inland areas and from seawater in coastal areas and making residual communal or industrial water again suitable for agricultural and other purposes such as artificial groundwater recharge. The research outcome will be an important resource for water supply and energy decision makers, energy and water sector representatives and administrators, policy makers, in governments as well as business leaders, energy engineers/scientists, academicians and power producers, financial sector, land planners, agronomists, and citizens interested in one of the most significant challenges for the next decade. It will be a challenge for you as potential PhD student working on the one or the other component of the interdisciplinary team including geothermalists, hydrogeo- logists, and engineers/scientists from chemical and energy engineers contributing in your research and future professional carrier for implementation and market penetration of desalination using geothermal desalination as economic zero-emission option.
Topic 11: Water Treatment using geological Materials: Sustainable Options for rural and urban isolated Areas
Use of natural geological materials for removal of metals (e.g. Pb, Cd, Cr, Zn) or metalloids (e.g. arsenic) from drinking water resources can be lowcost emerging tech- nologies suitable for rural and urban areas lacking centralized water supplies. This tech- nology is particular suitable at household level for poor people in remote rural settlements, especially when the materials are locally available and can be collected by the local population. Their low or zero cost makes these materials very attractive compared with synthetic or commercial materials. Sometimes, this may be the only option to provide safe water to very poor settlements. Our group evaluates the suitability of different geological materials for removal of contaminants from water which are mainly processes of ad- sorption, coprecipitation and ion exchange involving Fe- and Al-rich minerals and clay minerals present in the soils or sediments used for removal. Manganese minerals (todorokite, birnessite, cryptomelane, lithiophorite) and Fe oxides (goethite, hematite, and magnetite) and soils or sediments containing these minerals (e.g., oxisols, laterite), limestone, natural or iron-coated zeolites are promising sorbents. Clay minerals such as montmorillonite (and clays such as bentonite, consisting predominantly of montmorillonite) and therefore clay-rich soils may be suitable, too.
Our group is evaluating different geological materials as adsorbents for different con- taminants or groups of contaminants in function of site-specific conditions and necessities and identify the thereby occurring processes (adsorption - formation of inner- orouter-sphere complexes, coprecipitation, ion exchange, intraparticle diffusion) and sorption type (e.g.
Langmuir or Freundlich sorption terms). The individual benefits of the different geological sorption materials are evaluated, in terms of (i) raw water composition, grade of raw water mineralization, pH, Eh, (ii) contaminanttype, contaminant concentration, distribution of species, chemical composition and grade of mineralization in the raw water, (iii) guidelines for the remaining As concentration, (iv) socioeconomic constrains,(v) size of the treatment
device, complexity of installation and maintenance, (vi) infrastructure constraints (e.g.
electricity needs) and (vii) the geological materials locally available at the individual site where water needs to be treated. Experiments are performed using (i) batch experiments with laboratory water and natural waters at different initial solid-water ratios, different pH and Eh values, different initial contaminant concentrations and species distribution and different electrical conductivity of the water to be treated, (ii) column experiments and (iii) field trials(pilot studies) to evaluate suitable adsorbents and optimal conditions of the parameters tested for their influence on contaminant sorption efficiency.
Topic 12: Water Treatment using Constructed Wetlands (Phytoremediation)
Water that is naturally or anthropogenically contaminated by metals (e.g. Pb, Cd, Cr, Zn), metalloids (e.g. arsenic) and other contaminants can be treated using artificial wetlands or ponds with algae that is considered a cost-effective technology for water and wastewater treatment. Artificial wetlands offer great advantages over conventional treatment systems;
they operate on solar energy, require low external energy input, can achieve high levels of treatment, and involve inexpensive technology that is easily operated and maintained locally on level of small to middle-sized communities. The implementation process involves several steps. It starts with the selection of the most promising plants capable of removing the contaminants from water and retaining them in their roots; this process, called rhizofiltration, is quite successful for the contaminants removal. Our research group investigates the tolerance and removal capacity of different plants and algae for the removal of different metal and metalloids for individual site-specific conditions. The studies are conducted on laboratory scale and in future in a subsurface wetland prototype system with different units of different experimental conditions operated in parallel under continuous flow.
The tolerance of different plant speciesregarding an individual contaminant or assem- blage of different contaminants, is evaluated. The respective contaminant uptake/accumu- lation (removal efficiency) in the plants' biomass (roots and aerial parts) is determined for different plants grown in flooded substrate (simulating wetlands) under greenhouse con- ditions applying different initial conditions regarding contaminant concentration, different species distribution and different retention times. Biological absorption coefficients (BAC) and translocation factors (TF) are determined to evaluate suitability for use in phyto- stabilization and rhizofiltration for individual contaminants to be removed. Our target is further to investigate sustainable and environmentally friendly ways to dispose the con- taminant-rich biomass. Burning the biomass for producing bioenergy and at the same time strictly controlling and managing the exhaust gases to prevent any atmospheric con- tamination with the contaminant seems to be the most challenging solution that we follow to research.
Topic 13: In-situ Remediation of deep Aquifers
Conventional technologies for treating contaminated groundwater such as ex-situ pump-and-treat systems have several disadvantages due to their high costs, especially when the operation is long lasting and it becomes impossible to decrease the contaminant con- centration below the maximum allowable limit. Therefore in-situ technologies have been established or are recently under development Reactive barrier technology is the most frequently used in-situ technology but it requires excavation and is therefore applicable only to a depth of <20–30 m and therefore not suitable for deeper aquifers. Technologies suitable for deep aquifers include bioremediation, reactive zones, in-situ chemical oxidation/re- duction, multiphase extraction, natural attenuation, electrokinetics, etc. An array of reactants that promotes chemical or biochemical reactions or sorption processes in order to transform or immobilize pollutants exists, suitable for different site conditions and contaminant spe- cies. The use of nanoscale particles, injected as slurries (nanofluids) through wells into the underground where they form so-called “reactive zones” are state-of-the-art technologies still under development. Nanoparticles are typically injected directly into the subsurface environment to remediate contaminated groundwater plumes or contaminant source zones and may be suspended in the injected fluid to prevent particle agglomeration and enhance reactivity and mobility. Nano-sized iron, which is the most frequently used nano-metal has a high efficiency for elimination of a large amount of organic and inorganic pollutants.
Injection of the slurries can be performed by hydraulic fracturing, mixture in depth or injection under pressure depending on local conditions.
Task for the potential PhD student will be to investigate on laboratory scale the suitability of different nanoscale materials for remediation of sites with a specific contaminant of group of contaminants, such as nanoscale zeolites, metal oxides, carbon nanotubes and fibres, enzymes, microbes, various noble metals, and titanium dioxide. Anther in-situ chemical Our research in Mexico Advanced Materials Research Center (CIMAV): Construction of artificial wetlands prototype for removal of toxic metals and metalloids from water. (a) Constructed wetland prototype with plants; (b) Schematic of constructed wetland (photos: M.T. Alarcón Herrera)
treatment to be studied consists of the direct injection of an oxidant or reductant in the within an aquifer. A third research field are microbiological in-situ technologies that are also a very promising in-situ rehabilitation options. Here, bacteria through aerobic or anaerobic micro- biologic reactions can provide effective remediation of contamination of organic compounds and some metals and the metalloid arsenic.
