Page 23 - Industrial Wastewater Treatment, Recycling and Reuse

6 Industrial Wastewater Treatment, Recycling, and Reuse

Figure 1.4 India’s sources of water for industry.

It is quite evident that the availability of both surface water and ground-
water is declining, and industries have to look for alternative sources of water
supply if they are not self-sufficient through water recycling and reuse.
A recent trend in Mumbai, the financial capital of India, indicates increased
dependency of industry on treated municipal water, that is, sewage water.
Among the different industry sectors, thermal power plants consume the
most water and are termed water-intensive. In India, the thermal power
plant sector is a major power-generating source and accounts for 65%
of the total installed power capacity as per 2008 records. Further, it is
expected to grow at a rapid rate in view of a huge power demand and is likely
to constitute 75% as the total power sector expands. Not only is the ther-
mal power sector most water intensive, but it also discharges huge amounts
of wastewater and is one of the highest contributors to industrial wastewater
discharge.
3
As mentioned earlier, India generates nearly 6.2 million m of industrial
wastewater every day, which requires treatment before discharge to meet
environmental norms. Recent data, shown in Figure 1.5 (CPCB, 2009–10;
Frost and Sullivan, 2011, www.frost.com), indicates a huge gap between
wastewater generated and wastewater treated, highlighting the need for better
water management. If the wastewater is not treated, agricultural output could
be lowered if it is used for irrigation. Conversely, the runoff waters from
agricultural land, which may contain many hazardous chemicals such as
pesticides and fertilizers used in crop production, can also pose the threat
of surface water pollution.