Reusing water in industry has the potential to reduce the costs of water supply and wastewater treatment by industries and reduces pressure on water resources. Wastewater can be reused within a business itself, or between several businesses through industrial symbiosis. Depending on the type and quality of the wastewater, it may either be reused directly, or treated before reuse (i.e. recycled). The different technologies available for direct reuse as well as decentralised wastewater treatment for wastewater recycling are summarised in this factsheet.
Industrial water consumption makes up 22% of global water use (UNWATER 2012). In 2009, European and North American industrial water use accounted for half of their total water use, whereas in developing nations industrial water use ranges from 4-12% of national water use. As industrialisation in developing nations increases, industrial water use could potentially increase by a factor of five, strongly increasing pressure on water resources (WWAP 2009).
One method of curbing water consumption in industry is through the reuse of wastewater. Reducing the amount of water use by industries can lower water withdrawals from local water sources thus increasing water availability and improving community relations, increasing productivity per water input, lowering waste water discharges and their pollutant load, reducing thermal energy consumption and potentially processing cost.
Wastewater reuse in industry can take place within a business or between businesses and has the potential to reduce costs for businesses both on water bills as well as wastewater treatment. Depending on the contaminants present in wastewater and its future reuse, it can either be directly reused, or treated and reused (recycled).
A business can directly reuse wastewater that is clean enough for the purpose for which it is being reused. Process water is produced by industrial processes such as cooling and heating, and often contains few contaminants after use. In industry, both rainwater and process water can be reused for purposes such as:
For more information about directly reusing water within a business, see reuse within a business.
Direct wastewater reuse can also be practiced between businesses. The exchange of waste products for the mutual benefit of two or more businesses is also known as “industrial symbiosis.” In industrial symbiosis, all members profit from the arrangement by either reducing the inputs necessary in their production process (i.e. water, organic material) or by reducing the costs of wastewater treatment.
Industrial symbiosis can take place in three ways:
If wastewater is not suitable for direct reuse, decentralised wastewater treatment systems may be employed to reduce the level of contaminants to a level that is safe for reuse. This can be done within a business for its own reuse, or between businesses. Wastewater treatment and reuse between businesses can lower the costs of treatment for all businesses, thus making reuse options more economical.
Some possibilities for decentralised wastewater treatment systems include:
The choice for the specific treatment option depends on the quality required at the end. If water is to be used for gardening, a natural treatment such as a free surface constructed wetland where some nutrients remain in the water may be suitable, if space is available and loss of water through evapotranspiration is not important.
Some advanced options like membrane filtration and activated carbon may even produce treated wastewater of a better quality than freshwater, so that the treated wastewater can even be reused as process water where high water quality is required.
To ensure that the quality of the (pre-treated) wastewater or greywater is appropriate for reuse, the water quality should be tested for chemical composition, including pH, nutrient concentrations, pathogens, etc.
Almost any business can incorporate measures for reuse of wastewater. While direct reuse measures may be relatively easy to implement, the cost of implementing wastewater treatment systems may prohibit wastewater recycling within a business.
Between businesses, wastewater reuse potential depends on factors such as the distance between the businesses (cost of transport) and the wastewater production volume and quality. If wastewater treatment is needed, the participation of several businesses may significantly reduce treatment costs and therefore enable its reuse.
WORLD WATER ASSESSMENT PROGRAMME WWAP (Editor) (2009): Water in a Changing World - Overview of Key Messages of the United Nations World Water Development Report 3. Water in a Changing World. Paris and London: UNESCO & Earthscan. URL [Accessed: 19.10.2012]. PDF
GROBICKI, A. (n.y.): The Future of Water Use in Industry. Global Ministerial Forum on Research for Health. Geneva: World Health Organization. URL [Accessed: 19.10.2012]. PDF
This paper gives an overview about the water use in Industry of the past years and makes a projection of future uses. Furthermore, the paper gives advices how to save water in the future.
MCYINTRE, J.P. (2006): Industrial Water Reuse and Wastewater Minimization. Trevose: GeWater. URL [Accessed: 23.07.2010]. PDF
This document explains how to reuse water and wastewater in Industry.
ASHTON, W. S. (2008): Industrial Symbiosis in Puerto Rico: Environmentally Related Agglomeration Economies. New Haven, CT: School of Forestry & Environmental Studies, Yale University. URL [Accessed: 02.01.2012]. PDF
This paper conceptualises the relationship between agglomeration economies and industrial symbiosis, ﬁnding that many negative environmental externalities can be reduced while increasing production efﬁciency. Four industrial regions of Puerto Rico, all with agglomeration economies, but only two with signiﬁcant industrial symbiosis, highlight the contribution of symbiosis and how it can inﬂuence both static and dynamic agglomeration economies.
BAAS, L. (2011): Planning and Uncovering Industrial Symbiosis. Comparing the Rotterdam and Oestergoetland regions. In: Business Strategy & Environment, Special issue Industrial Ecology 20, 428-440. URL [Accessed: 19.11.2012]. PDF
Academic discussion of the planned industrial symbiosis activities in Rotterdam Harbor around waste heat reuse and the unplanned industrial symbiosis and biogas activities in the forest industry of Oestergoetland, Sweden.
BEERS, D. van; CORDER, G.; BOSSILKOV, A.; BERKEL, R. van (2007): Industrial Symbiosis in the Australian Minerals Industry. In: Journal of Industrial Ecology 11, 55-72. URL [Accessed: 15.05.2012]. PDF
An academic review of industrial water reuse between mining industries in Australia. Barriers and triggers to cooperation are discussed.
This document explains how you can save water in textile industry. It contains good strategies how to conserve water in different process steps.
UNEP (Editor) (2007): Water Utilisation in African Beverage Industries: Current Practices and Prospects. Nairobi: UNEP, Division of Technology, Industry & Economics. URL [Accessed: 09.08.2010]. PDF
This document explains how you can save water in beverage industry. It contains good strategies how to conserve water in different process steps.
This document illustrates the water use in industry around the world.
UNEP (Editor) (2002): Freshwater use by sector at the beginning of the 2000s. The Hague: United Nations Environment Programme (UNEP), GRID-Arendal. URL [Accessed: 29.07.2010].
WBCSD (Editor) (2009): Water for Business. Initiatives guiding sustainable water management in the private sector. Geneva: WBDSC and IUCN. URL [Accessed: 19.10.2010]. PDF
The future of any business depends on the sustainability of water resources, which are increasingly under pressure. At the same time, consumer awareness and investors' increased scrutiny of corporate water risks have resulted in stronger expectations that companies should reveal their ‘water performance'. To respond effectively, the business community needs guidance, tools, standards and schemes to enable change to more sustainable practices. This is what this publication aims at providing.
WBCSD (Editor) (2009): Business in the world of water: WBCSD Water Scenarios to 2025. Geneva: WBCSD. URL [Accessed: 19.10.2012]. PDF
The H2O scenarios offer three stories about the role of business in relation to the growing issue of water in the world. These stories do not try to cover everything but attempt to bring to life a limited number of alternative future environments that will challenge our economic viability, social legitimacy, and global fitness in the marketplace.
MCDONOUGH, W. (2000): The Hannover Principles. Design for Sustainability. Charlottesville, VA: William McDonough Architects. URL [Accessed: 15.05.2012]. PDF
The Hannover Principles provide nine principles to create sustainable businesses for a healthier planet. The principles are simple and inspiring and can be incorporated into training materials within firms.
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Industrial ecology aims to reduce the environmental impact of industry by examining material and energy flows in products, processes, industrial sectors, and economies. This web site provides more information on that topic.
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Water.org is a nonprofit organization that has transformed hundreds of communities in Africa, South Asia, and Central America by providing access to safe water and sanitation. Water.org works with local partners to deliver innovative solutions for long-term success. Its microfinance-based WaterCredit Initiative is pioneering sustainable giving in the sector.
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International Society for Industrial Ecology, a research institute based out of Yale University in Connecticut, USA.
http://www.zerilearning.org/ [Accessed: 19.10.2012]
This initiative in rural Fiji includes reusing brewery waste to grow mushrooms, pig waste to produce methane gas and intensive pond management to raise fish and food crops. This website provides a brief overview.
http://www.roi-online.org/ [Accessed: 15.05.2012]
The Resource Optimisation Initiative is a non-profit based in Bangalore, India providing planning tools for policy makers and case studies in developing countries.
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Progress in Industrial Ecology is an international journal started in 2004 published by InderScience Publishers.
http://www.symbiosis.dk/ [Accessed: 15.05.2012]
This website for Kalundborg’s Centre for Industrial Symbiosis has a host of information on their projects, organisation and strategies. They describe what they think are the fundamental criteria for reuse between businesses.