KENYA WATER INDUSTRY ASSOCIATION
Wastewater is now seen as a potential resource and its use, or recycling after suitable treatment, can provide economic and financial benefits.
Wastewater can be used within the business itself or between several businesses through‘ industrial symbiosis’. Industrial water consumption is responsible for 22 % of global water use( UN-Water, 2012). In 2009 in Europe and North America, water consumption by industries was 50 % as compared to 4-12 % in developing countries( WWAP, 2009). It is expected that in rapidly industrialising countries, this proportion could increase by a factor of five in the next 10-20 years. Therefore, there is a strong incentive to use wastewater in-house and locally, based on cost savings alone.
Businesses can directly use some wastewater, providing it is fit for purpose. For instance, using process water for cooling or heating, or rainwater from roof collection or concrete aprons for toilet flushing, irrigation or vehicle washing.
sterdam, is comparable to that of a small city with a population of 45,000. About half of the wastewater originates from passengers and businesses at the airport, 25 % is discharged by aircraft and catering, and the remaining volume is produced by other aviation-related businesses. The on-site wastewater treatment plant biologically purifies water to a quality fit for discharge into local waterways.
WASTEWATER AND INDUSTRY
Societal and environmental pressures over recent years have led to a growing movement for industry to reduce its wastewater and to treat it before discharge.
Examples:
• An industrial ecosystem. In Kalundborg, Denmark, the by-products of one enterprise are used as a resource by other enterprises, in a closed cycle. The Asnæs Power Station receives 700,000 m 3 of cooling water from Statoil each year, which it treats and then uses as boiler feed water. It also uses about 200,000 m 3 of Statoil’ s treated wastewater for cleaning each year. The savings to local water resources are considerable: nearly 3,000,000 m 3 of groundwater and 1,000,000 m 3 of surface water per year. 7
• Reclaiming water from mining. The Witbank coalfields are located around Emalahleni, a small city in
7 Domenech and Davies( 2011),“ Structure and morphology of industrial symbiosis networks: The case of Kalundborg”, Procedia- Social and Behavioral Sciences, vol 10, 2011, pages 79-89: http:// www. sciencedirect. com / science / article / pii / S1877042811000127
16 Africa Water, Sanitation & Hygiene • March- April 2017