UV disinfection is widely used in industrial and municipal water treatment. However, to sustainably manage the increasing pressures on water supplies and to address energy and environmental costs and concerns, new and innovative approaches are needed.
The objective of water treatment is to remove contaminants and/or microorganisms present in the source water by a combination of biological, chemical, and physical processes to make it safe for drinking or industrial use. Usually the final step in treatment is disinfection; removing or killing pathogenic microorganisms. UV light is a recognised and proven method of effective treatment. It is able to destroy 99.99% of harmful microorganisms without changing the taste or odour of the water, and it has the additional benefit of being able to break down certain chemical substances in water, such as chloramines which can form in swimming pools. The EU market size for UV disinfection is substantial, approximately € 1.8 billion, which represents 41% of the global market1 with a projected annual growth of 10–12%.
Water supply and sanitation in the EU is the responsibility of each member state, but in the 21st century union-wide policies have come into effect. Water resources are limited, and supply and sanitation systems are under pressure from urbanisation and climate change. Recent studies show that competing demands for scarce water resources may lead to an estimated 40% global water supply shortage by 20302, also affecting large parts of Europe. Competition for clean water is expected to increasingly lead to social, economic, environmental and global geo-political consequences. The EU has a requirement of focus on green growth and becoming more efficient in its use of resources (including water) to achieve a sustainable recovery from the recent economic crisis, adapt to climate change and build resilience to disasters. Tackling these challenges holds significant potential to boost the competitiveness and growth of the European water sector. There is also substantial potential for green growth in other water-related sectors (water-using industries, water technology developments, etc.) where innovation can increase operational efficiency.
UV disinfection in itself doesn't directly affect water consumption, but does have a material impact on the energy and therefore carbon footprint of production of potable water. It also reduces the need for chemical use. Indirectly, UV can reduce water consumption if it can provide the means to return waste water into processes in a circular pattern of consumption, as cleaned and disinfected water.
UV disinfection isn't new technology – it's been in use since the early 20th Century with exponential growth in the latter half. However, the basic design of a UV lamp hasn't changed much in that time – it's been optimized, improved and maximised, but at its core it is largely unchanged.
In order to meet the growing demand for chemical free clean water worldwide and reduce the environmental and cost impacts of treatment of water, a step change is needed.
Gaps in the Market
Water has high strategic and economic importance. Protecting water resources and promoting sustainable economic growth are interlinked and call for an integrated approach. The European water sector has an average growth rate of 5% and had a turnover of about € 80 billion p.a. (about a third of the world water market) in 2011.3 Boosting the development of innovative solutions to deal with water challenges and supporting their deployment and market uptake brings significant economic opportunities in a rapidly growing world market for water solutions, in which many European companies are active. Furthermore, the costs of inaction are significant in terms of losing global market opportunities for European industry.
Water and energy are inextricably linked within what is often referred to as the 'water-energy nexus'. The term captures all aspects of water and energy interactions, both within 'water for energy' (the water needed to generate and transmit energy) and 'energy for water' (the energy needed to collect, clean, move, store and dispose of water). Within this project, the main focus is on 'energy for water'. In the UK, where roughly 3% of generated electricity is used by the water industry alone, energy efficiency is of growing interest.4 A first estimate from the UK indicates that, without intervention, achieving the higher water-quality standards required by the European Water Framework Directive could increase CO2 emissions by 110,000 tonnes per year.5
One of the four consortium partners in Eco-UV, Hanovia, supply UV treatment systems to a variety of industries, including food and beverage, pharmaceutical, leisure (swimming pools and saunas) and aquaculture. When their customers are questioned, the areas where they wish to see future reductions are in energy usage and running costs. The two are linked; energy accounts for 50% of the running costs of an Olympic-sized swimming pool, with maintenance at 16%.
Recent innovations in UV systems have focussed on optimising the delivered UV dose per unit energy consumed, by taking account of the hydrodynamics of the UV chamber and sizing the lamp output appropriately for the chamber size and water throughput. It is generally agreed that these approaches, though valuable, are not likely to be able to give significant further improvements in future.
The remaining area that is ripe for innovation is the UV lamp itself.
Advancing the State of the Art
The overall aim of Eco-UV is to produce ultra-high efficiency UV lamp technology for use in water treatment. The focus will be to provide a disseminated demonstration that the developed next generation UV treatment technology addresses the efficiency and total life cost gaps in the market today:
Optimised efficiency for the treatment of water with guaranteed bio-security.
Providing the most cost-effective procurement, operational and service possibilities for all end-users of UV water treatment.
Energy-efficient lamp technology
With significant energy and carbon saving a core market demand, Eco-UV's lamps will give the most efficient and effective dose per kW energy expended of all UV treatment technologies while ensuring process safety and reduce space requirements for new build systems.
Lower maintenance technology
Eco-UV's technology will offer substantially improved lamp lifetime of conventional lamps, thereby reducing the associated indirect carbon footprint of running the treatment chamber for an extended lifetime, not just through its energy consumption but also the embedded carbon of less frequent service intervals means less waste lamps and ancillary parts for disposal, and fewer visits by service personnel saves the associated vehicle emissions, etc.
Ecologically-friendly lamp technology for higher power treatment systems
Eco-UV lamps will also be addressing the harmful compounds used within the lamps to meet the demands of existing end-users whose processes are sensitive to the substances used to generate UVC, such as the pharmaceutical industry, as well as reducing hazardous substances and meeting the tightening WEEE requirements.
Validated technology in the EU for industrial rather than municipal applications
Current validation protocols are designed primarily for municipal applications with few if any standards applicable to industry. Part of Eco-UV's focus is to explore the principles for a future standardised UV reactor evaluation for different industrial applications. If adopted, such standards would drive up bio-security standards across the industrial sector and increase market confidence in UV as a disinfection solution.
The new technology used for ultra-high efficiency lamps will provide commercial opportunities on a world-wide basis for water treatment but also into other UV applications.
The new lamp and electronic ballast setup will be much smaller, which will enable usage of UV treatment in much smaller spaces, so growing the potential for this clean and efficient technology.
The new technology doesn't stop there – it will provide a new lamp design template for an ongoing process of improvements, optimisation and maximisation which may lead onto to new possibilities; new applications, new spectral outputs and new adaptabilities.
European citizens, societies, agriculture and industries will increasingly need innovative solutions to meet the need of cleaning and using water in a more efficient and effective way. Innovative thinking and smarter use of technology, such as that of project Eco-UV, have the potential to bring new solutions quickly and efficiently to the market while responding to the needs of end-users in urban, rural and industrial areas.
- McKinsey & Company, 2009. Charting our Water Future: Economic frameworks to inform decision making.
- UK Water Industry Research Energy Efficiency in the UK Water Industry: A Compendium of Best Practices and Case Studies (UK WIR, 2010).
- Ainger, C. et al. A Low Carbon Water Industry in 2050 (Environment Agency, 2009).