Page 336 - Industrial Wastewater Treatment, Recycling and Reuse

308 Industrial Wastewater Treatment, Recycling, and Reuse

Table 7.9 Economics of different levels of treatment through conventional measures
Primary
Primary treatment
treatment +ultra-
Primary +ultra- filtration
Salient Features treatment filtration +RO Remarks
Capital cost (Rs. 30.0 90.64 145 The cost details
lakhs) are for
Annual capital 5.79 18.06 29.69 municipal
cost at 15% sewage at
p.a. interest sewage
and contribution of
depreciation 80% of water
Operation and 5.88 7.04 12.63 supply rate
maintenance
(lakhs per
year)
Annual burden 11.85 27.1 42.5
(annual and
maintenance,
Rs. lakhs)
Treatment cost 34.08 52.40 73.22
(Rs./KL)
(without
interest and
depreciation)

Source: Kaur et al. (2007)

staffing, the facilities constructed to treat wastewater donot function properly
and remain closed most of the time (CPCB, 2007). Utilization of biogas gen-
erated from UASB reactors or sludge digesters is also not adequate in most
cases. In some cases the gas generated is being flared and not being utilized.
One of the major problems with wastewater treatment methods is that none
of the available technologies has a direct economic return. Because there are
no economic returns, local authorities are generally less interested in addres-
sing wastewater treatment. A performance evaluation of STPs carried out by
CPCBinselectedcitieshasindicatedthatoutof92 STPsstudied,26STPshad
not complied with prescribed standards in respect to BOD, thereby making
these waters unsuitable for household reuse. As a result, although the waste-
water treatment capacity in the country has increased by about 2.5 times since
1978-1979, hardly 10% of the sewage generated is treated effectively, while
the rest finds its way into the natural ecosystems and is responsible for
large-scale pollution of rivers and groundwaters (Trivedy and Nakate, 2001).