Page 20 - Industrial Wastewater Treatment, Recycling and Reuse

Industrial Wastewater Treatment, Recycling, and Reuse: An Overview 3

beintheformofeconomicscarcity,wherealthoughwaterisavailable,thereare
nomeans/infrastructuretoprovidewaterofthequantityandqualityneeded.As
far as the global water scenario is concerned,as a whole, there may not be water
scarcity. However, since the distribution of water across the globe is not uni-
form, parts of world are increasingly facing water scarcity. The origin of water
scarcity can be natural in some regions because of reduced rainfall or climate
changes. The human factor, however, is most critical in aggravating this prob-
lem by wasting water, polluting water resources, and/or inappropriately man-
aging water. According to recent reports (Corcoran et al., 2010; UN Water,
2008), it is believed that the total wastewater—combining sewage, industrial,
andagricultural—dischargedgloballyistensofmillionsofcubicmetersperday.
Itisalsobelievedthatasignificantportionofallwastewaterindevelopingcoun-
triesisdischargeduntreated,resultinginlargepollutionofriversandotherwater
bodies, consequently endangering living species including any surrounding
population dependent on these water sources. Some recent reports, such as
UN Water, 2008 and World WaterAssessmentProgramme, 2009,alsosuggest
that nearly 80–90% of all the wastewater in developing countries is discharged
3
directly into surface water bodies. In India, nearly 6.2 million m of untreated
3
industrial wastewater is generated every day (of the total 44 million m /day
wastewater). Only 26% of domestic and 60% of industrial wastewaters are
believed to be treated in India (Bhardwaj, 2005; Grail, 2009; Kaur et al., 2012;
Kamyotra and Bhardwaj, 2011; CPCB, 2005a,b; CPCB 2007b, www.ais.
unwater.org).
India is projected to be severely water stressed by the year 2025
(Figure 1.1) and thus needs to carefully evaluate water management options.
Because India is a developing country, its industrial development is rapid.
India is also an agriculture-based country. Both these aspects require increased
water consumption, and with increasing population, India is poised to become
water stressed by 2020, according to a recent FICCI report (2011). Figure 1.2
shows typical water consumption patterns for India (Amarasinghe et al., 2007),
and Figure 1.3 shows a typical water demand pattern worldwide. While
developed countries consume much less water for agriculture, of the order
of just 30% of the total, developing countries such as India consume water
foragricultureatarateof80%.IndianstatessuchasMaharashtra,UttarPradesh,
Andhra Pradesh, Tamil Nadu, and Karnataka use 90% water for irrigation.
This is mainly because these states produce the most water-intensive crops,
accounting for 70% of total crops in India.
Further, although the industrial sector in developing countries con-
sumes close to 10% of the water, for India, according to a recent survey