Multidisciplinary research can deliver solutions for more sustainable water management structures, as evidenced by a team of researchers implementing the EC FP7 project, ATWARM.
Research and innovation for improved water quality
Global water resources are under mounting pressure from factors such as population growth and increased demand from industry and agriculture. In developing countries, lack of safe water supply is directly linked with a low quality of life: reduced life expectancy, poor education and adverse impacts on economic development. Water is essential for life. Sustainable water management is necessary across the globe.
Water protection in developed nations is ensured through the effective implementation of water policy. EU legislation such as the Water Framework Directive, the Groundwater Directive and the Nitrates Directive contribute to the delivery and protection of good water quality of rivers, lakes, seas, groundwater and drinking water in the Member States.
The EU supports water research and the development of new technologies for the water sector. Since the 1980s, water research has accounted for growing numbers of projects and an increasing budget in the EU’s Research Framework Programmes (FPs). The total EU contribution to projects funded over the last ten years exceeded €1.3 billion. In total, more than 800 water research projects have received EU support under the Sixth and Seventh Framework Programmes (FP6, FP7) http://europa.eu/rapid/press-release_MEMO-12-203_en.htm
One example of this support is through the FP7 People Marie Curie project, ATWARM – a €3.5 million Marie Curie ITN project which combines scientists with engineers to develop new treatment and monitoring technologies for improving and sustaining water quality.
ATWARM – Advance Technologies for Water Resource Management – is a four year project with seven partners in three European countries. Sixteen young researchers have been recruited with a mandate to deliver innovations in water analysis, water and wastewater treatment, and applications for groundwater, fresh water, marine water and municipal wastewater systems.
ATWARM research activities seek to develop advanced technologies that will provide more effective and sustainable water and wastewater treatment processes, and improve surface and ground water quality. Wastewater treatment
Significant challenges exist for wastewater treatment across Europe. Stringent discharge standards necessitate improved treatment performance and capabilities at wastewater treatment plants. Meeting these standards with current technology requires large amounts of energy, chemicals and land resources, however.
1. Persistent organic pollutants
Greater urbanisation, industrialisation and intensification of water reuse have meant increased pressure to remove organic pollutants such as solvents, pesticides or pharmaceuticals from drinking water systems.
A growing challenge for sustainable wastewater treatment is to protect treatment systems and water systems from recalcitrant priority substances such as pharmaceuticals or other organic contaminants. Recalcitrant compounds are those which are resistant to breakdown in the environment or by conventional biological wastewater treatment – passing through these systems, untreated, to accumulate in the environment.
Treatment processes such as advanced oxidation are expensive, requiring addition and subsequent removal of supplementary chemicals, yet some organic compounds remain, intact. Pulsed electrical discharges – generated by releasing a pulsed stream ‘corona discharge’ in water – represent a novel opportunity to remove a variety of organic contaminants.
Such electrical discharges generate highly reactive species (the free radicals ·OH, ·O, ·H) and transmit various physical effects, such as thermal effects, shock waves and intensive ultraviolet irradiation. Application of such a system to degrade persistent organics is under investigation and shows promise for deployment as a polishing step for municipal wastewaters containing low concentrations of organic compounds or pharmaceuticals.
An alternative technology, also suitable to low concentrations of organics, exploits photocatalytic adsorbents such as Titanium Dioxide in combination with graphene. Initial results for this material indicate that it can treat a mixture of common pharmaceutical compounds found in water such as salbutamol, propopanol or ibuprofen. Technologies such as these are important innovations to ensure the quality of surface and groundwater systems, to which treated municipal effluent is ultimately released. They also offer significant advances for the delivery of high quality drinking water.
Eutrophication caused by excessive levels of phosphorous (P) and nitrogen (N2 gas, NO3, NO2) is one of the main challenges to water quality status in European water bodies. To minimise the impact of nutrients, Member States are required to limit the ingress of agricultural run-off to surface water by restricting the spread of fertiliser on fields and crops at certain times of the year.
Nutrients can be removed from wastewater at municipal wastewater treatment plants by a variety of methods but there is a lot of variability in system performance and reliability. Novel methods for nutrients’ removal and recovery at wastewater treatment plants (WWTP) are being investigated by ATWARM researchers.
Removal of existing nutrients from wastewater is being addressed by the use of microalgae, which, given the correct lighting conditions grow naturally in wastewater. As they grow, the microalgae remove N and P from wastewater, and assimilate CO2 for photosynthesis. O2 produced during photosynthesis is beneficial for the aerobic bacteria in the primary tanks of the WWTP.
A resultant rise in pH permits metals and P precipitation into the sludge fraction. Harvesting microalgae for assessment as an anaerobic digestion (AD) feedstock for production of biogas gave promising results. Opportunities to exploit algae for improved wastewater treatment and energy recovery are of interest to many companies and utilities’ providers.
Algae have a large capacity for nutrient uptake and can be used as a feedstock for biogas production or oil recovery. There are significant challenges to the controlled growth, harvesting and processing of algae in open treatment systems. Contamination from other species, achievement of adequate illumination, concentration and cell processing all affect the profitability. Selection of the most energy efficient processes for micro algal harvesting and conditions for processing will be another project.
Phosphorus recovery and recycling is a key area of concern for the wastewater sector. Worldwide P rock reserves are being rapidly depleted – estimates are of only 50 years remaining – and its value will increase in coming years. Heavily P loaded wastewaters represent an opportunity to recover valuable phosphorus that would otherwise be discharged to surface waters.
An ATWARM researcher is manipulating operating conditions of WWTP at lab-scale, to encourage increased microbial uptake of phosphorus. Excess or ‘luxury’ P uptake, in excess of normal metabolic requirements, can be stimulated as a response to environmental stress, e.g. pH shock or carbon starvation. This research focuses on the biochemical triggers for P uptake by microorganisms commonly found in WWTP and its storage in cells as long polyphosphate chains. Once a clear understanding of the biochemistry is established, the process will be tested at pilot-scale on site.
Identifying the source of pollution for control and legislative purposes is often expensive, requiring labourious sample collection and analysis. In the case of organics’ contamination, a simpler method is proposed which will utilise sludge analysis to determine when and where a persistent organic pollutant entered the wastewater pipe network.
Microbial biofilms which line wastewater pipes absorb and retain compounds, and so represent a useful tool to ‘trace’ environmental contaminants. A better understanding of how these pollutants are absorbed and released by biofilms will enable environmental regulators to exploit the ‘memory’ of biofilms and accurately trace the contamination back to its sources. Full application of the tool should permit more accurate prosecution of environmental crime and fair application of the ‘polluter pays’ principle.
Many parts of Europe, including parts of France, Germany, Netherlands, Ireland and the UK, are ‘nitrate vulnerable zones’; that is, highly susceptible to pollution from the nutrients nitrates and phosphorous. A challenge exists to identify, trace and mitigate the sources of these nutrients to our water systems.
ATWARM research has developed an analytical tool which can identify whether nitrate pollution originates from domestic or agricultural sources by analysis of its chemical signature. This tool will inform rivers’ management and will aid targeted treatment and punishment of polluters. It has attracted interest and support from a number of environmental regulators.
4. Water – energy nexus
Conventional wastewater treatment uses huge amounts of energy. Traditionally, improving the level of wastewater treatment performance to achieve high effluent quality has come at the cost of increased energy input. As a result, the wastewater treatment sector is one of the largest consumers of energy – specifically electricity for pumps, air-blowers or stirrers – in Europe.
The UK water sector currently utilises 2-3% of net electricity usage in the UK, releasing equivalent to approximately four million tonnes of greenhouse gas (GHG) emissions (carbon dioxide equivalent) every year. Over the last ten years, however, as overall UK GHG emissions have gone down, the water industry’s emissions have actually gone up by 30%. There is a need, therefore, to address the high energy requirements and emissions of the water sector.
To reduce these operational costs and achieve carbon reduction commitments, less energy intensive and more sustainable means of wastewater treatment must be developed. One ATWARM project is developing a carbon accounting system which will enable an accurate understanding of the embedded and operational carbon costs associated with any given treatment process. This system provides information to the water company, enabling investment in the most appropriate technology to meet treatment requirements, and limit the use of energy and carbon.
New processes and modifications of existing technology will further reduce energy costs of wastewater treatment. Anaerobic digestion (AD) has long been associated with the recovery of energy from wastewater sludge. Biogas produced by the AD process can offset the energy requirement of wastewater treatment. AD efficiency is sometimes limited due to high heating requirements and low energy concentration of influent, however.
ATWARM research will optimise the sustainability of municipal wastewater treatment by investigating the effects of fortifying the strength of WWTP sludge, potentially maximising the volume and potency of methane generated from the AD plant. Recovered methane should be used on site to offset costs.
Research impact on society
These novel applications are exciting, benefitting society, the environment and the water industry. They represent environmentally friendly innovations for water and wastewater treatment, which inlude:
• Alternative options to strong oxidising agents • Novel materials that have superior adsorptive properties and are easily regenerated • More efficient on site energy generation systems • Systems to promote in house energy and carbon savings • Mechanisms to recover valuable components (N, P) from the wastewater stream • New tools for monitoring water pollution and pinpointing pollution sources
EU sponsored research aims to develop new technology, products and expertise to boost wealth creation and employment. The ATWARM researchers have a commitment to pursue the technology transfer and commercial opportunities arising from the project – all projects are constantly assessed for exploitation potential in the marketplace.
The researchers are attuned to delivering new products and processes to market, and are in the fortunate position of having access to a network of industrial mentors who provide advice and mentoring in this regard. Already a number of potential products and services are being developed and there will be the opportunity for companies to exploit these in partnership with the research teams involved.
Trends and challenges
There are numerous challenges to delivering innovation to the water sector and several trends that indicate the direction of technology development in the short to mid term.
Other research projects within the ATWARM programme are developing novel technologies for analysis of drinking water, surface water and groundwater, promoting rapid, more efficient and less expensive monitoring systems for surface water and groundwater.
Groundwater contaminated with BTEX (benzene, toluene, ethylbenzene, and xylene), phenol and polyaromatic compounds from oil spills, or by leaks from fuel stations is an issue for developers, homeowners, and businesses.
Traditionally, collection, transport, preparation, analysis and reporting results of groundwater samples is time consuming and expensive.
ATWARM research has produced simple, rapid and efficient methods for detection of pollutants: one chemical system – a miniature differential mobility spectrometer; and one microbiological system – based on gene probes.
Groundwater contaminated by metals, especially arsenic, is a major concern in many parts of the developing world. Technologies to address this contamination must be robust, low tech and low cost. Naturally occurring, inexpensive adsorbents, such as laterite, represent an opportunity to treat this contamination. Laterite can absorb arsenic and other metals from water – applicable to groundwater and industrial wastewater streams, e.g. electronic and metal finishing industry.
2. Marine systems
European coastal areas and beaches are affected by point and diffuse pollution from sewage – run-off and sewage outfalls. There is a need for rugged monitoring systems for faecal matter contamination. ATWARM research has highlighted the importance of continuous monitoring for informing sampling regimes in dynamic environments such as coastal bays and ferry routes.
Continuous monitoring can act as a decision support tool. A new method, based on β-D-Glucuronidase (GUD), can quantify the amount of E.coli and enterococci in water and its sediments. The ‘gut microbes’ are reliable indicators of recent faecal pollution. Compared with the traditional ‘culture-based’ methods, which can underestimate bacterial counts in water samples containing particle associated bacteria, the GUD method has the potential to give a more accurate estimation of the real E.coli population.
3. Surface water
On site analysis – Monitoring surface water quality is a topical issue of great concern across Europe. Advances to develop more economical, rapid, accurate analytical tools for deployment at site for long periods is highly desirable. Such innovations are being developed and tested by ATWARM researchers, who are testing novel biomimetic materials in combination with a low cost, wireless optical sensor for application in environmental water quality monitoring systems.
Laboratory analysis – Standardised and accurate methodologies for the determination of contaminants are a key component of the legislative framework and monitoring regimes of the water sector. Total petroleum hydrocarbons pollution in seawater, groundwater, wastewater and surface water gives rise to complex samples that prove challenging to routine analysis in environmental laboratories. An ATWARM project is working to overcome these challenges to deliver an improved, accredited method for detection of Total Petroleum Hydrocarbons and anticipate its validation and widespread use.
Published: 31st May 2013 in AWE International