Page 317 - Industrial Wastewater Treatment, Recycling and Reuse

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Table 7.3 Atmospheric water balance of India (http://www.nih.ernet.in/rbis/india_
information/Water%C2%A0Budget.htm)
Inflow Outflow
Parameter Value Parameter Value
13 P 400
V AI
1440 1318
V I V o
278 13
E T V AE
Total 1731 Total 1731
10
3
All components in (10 )m .
Source: Hydrology and Water Resources system for India.
P + I ¼ Q + E T + Q + DS
g
s
where P is total precipitation; E T , total evapotranspiration; I, sum of surface
water (I s ) and groundwater (I g ) flow; Q s surface water outflow to oceans and
other countries; (Q g ) ground outflow; and △S soil moisture change.
A diagrammatic representation of the hydrologic water balance for India
is shown in Figure 7.1. The hydrologic water balance of India is shown in
Table 7.4. It is assessed from Table 7.4 that if the precipitation reaches a low
value, artificial augmentation of water resources through recharge, recycle
and reuse would be an optimal choice for sustaining water balance of India.

7.2.6 Water Balance: Convergence to Recycling and Reuse
The infrastructural development for sewage and wastewater treatment has
not kept pace with wastewater generation. As a result, vast amounts of pol-
luted water are being discharged into natural waterways, with pollutants well
above the permissible levels (Lorenzen et al., 2010). In many Indian cities,
the wastewater discharges comprise domestic and industrial wastewater and
are often mixed and not separately accounted for in wastewater reuse. Lack
of systematic record-keeping of the different discharges makes it difficult to
arrive at reasonable estimates of wastewater discharge and its quality (Heg-
gade, 1998; Misra, 1998). For the period 1947–1997, a sixfold increase in
wastewater generation was recorded in Class I cities and Class II towns. Cur-
rent generation for Class I cities and Class II towns is more than 38,000 mil-
lion liters per day, out of which only 35% is treated (CPCB, 2009).
Conservation, augmentation, and recycling of urban water are major foci
in India’s national water policy (CIA, 2009). The policy also advocates
the reuse of treated sewage in view of the looming future water scarcity.
Thus, the policy support for reuse of treated wastewater from STPs is inher-
ently embedded in the overall water policy of India, despite the shortcom-
ings at the implementation level. The Ganga Action Plan was one of the