To
use or to misuse
That is the
question industries need to think over
Water
use in industry is a double-edged sword. On one hand it puts immense
pressure on local water resources. On the other, wastewater discharged
from the industry pollutes the local environment. Water is required,
often in large volumes, by industries as process inputs in most industries.
In other cases, like food and beverage and chlor-alkali industry,
water is used as a raw material: turned into a manufactured product
and exported out of the local water system.
However,
in most industries it is essentially used as input and mass and heat
transfer media. In these industries a very small fraction of water
is actually consumed and lost. Most of the water is
actually meant for non-consumptive process uses and is ultimately
discharged as effluent.
Quantity
and quality
The amount of water available matters but so also does its quality.
Industry requires water of good quality for its use, and for this
it uses cleaner upstream water. However, the water it discharges is
always of lower quality than the feed water and this wastewater is
discharged downstream. At best the wastewater discharged represents
a quality that can be recycled for lower grade of industrial use and
at worst represents water quality which is unsuitable for every use
other than navigational puposes. In other words, this water is unfit
for usage, is seldom used by the industries and usually used for certain
agricultural purposes or by villagers to meet their daily needs.
| Of
wastes and wants: Water use in India |
| Industrial
Sector |
Annual
wastewater water
discharge
(million cubic
meters) (%)
|
Annual
consumption (million cubic meters) |
Proportion
of water consumed in industry |
| Thermal
power plants |
27000.9
|
35157.4
|
87.87
|
| Engineering
|
1551.3
|
2019.9
|
5.05
|
| Pulp
and paper |
695.7
|
905.8
|
2.26
|
| Textiles
|
637.3
|
829.8
|
2.07
|
| Steel
|
396.8
|
516.6
|
1.29
|
| Sugar |
149.7
|
194.9
|
0.49
|
| Fertiliser
|
56.4
|
73.5
|
0.18
|
| Others
|
241.3
|
314.2
|
0.78
|
| Total |
30729.2
|
40012.0
|
100.0
|
|
Note:
For methodology see www.downtoearth.org.in
Source:
Estimated by CSE based on the wastewater discharged data published
by CPCB in "Water quality in India (Status and trends)
1990 - 2001".
|
Major
consumers
Water consumption depends on the type of industry. Whereas thermal
power, textiles, pulp and paper and iron and steel are highly water
intensive sectors, industrial sectors like chlor-alkali, cement, copper
and zinc and plastics require little water.
Data on actual water consumption in India is absent. However, the
data on wastewater discharge by various industrial sectors in the
country is available. The data on wastewater discharge has been complied
by CPCB. According to CPCB, the total wastewater discharged by all
major industrial sources is 83,048 million litres per day (mld). This
includes 66,700 mld of cooling water discharged by thermal power plants
(TPPs). Out of the remaining 16,348 mld of wastewater, TPPs generates
another 7,275 mld as boiler blowdown water and overflow from ash pond.
Is
it possible...
In the absence of data on actual water consumption is it possible
to chalk out a water consumption pattern for Indian industry? The
Centre for Science and Environment (CSE) has attempted to arrive at
an estimate based on the wastewater data of CPCB.
According
to CPCB the annual water consumption in Indian industry is 40 billion
cubic meters and the annual wastewater discharge is about 30.7 billion
cubic meter. Therefore, the overall ratio of wastewater discharged
to freshwater consumption in Indian industry works out to be about
0.77. That is, for every cubic meter of water consumed by
Indian industry, 0.77 cubic meters of wastewater is discharged. Considering
this, CSE has estimated the possible water consumption in various
industrial sectors in India (See table: Of wastes...).
Guzzlers
Inefficent
water use by industry
The ratio of water consumption and economic value creation in
Indian industry is poor. For every cubic metre of water that Indian
industry uses, it generates merely US $7.5
economic productivity
|
| Country |
Industrial
water use (billion cubic metres) |
Industrial productivity (million US $) |
Industrial
water productivity (US $ / cubic metre) |
| Argentina
|
2.6
|
77171.0
|
30.0
|
| Brazil
|
9.9
|
231442.0
|
23.4
|
| India
|
15.0
|
113041.0
|
7.5
|
| Korea,
Rep. |
2.6
|
249268.0
|
95.6
|
| Norway
|
1.4
|
47599.0
|
35.0
|
| Sweden |
0.8
|
74703.0
|
92.2
|
| Thailand
|
1.3
|
64800.0
|
48.9
|
| United
Kingdom |
0.7
|
330097.0
|
443.7
|
| Source:
World Bank, 2001
|
Thermal
Power Plants (TPPs): Most TPPs in India are owned by the
government. Indian TPPs are one of the highest consumers of water
as compared to their global counterparts. On an average, for every
1000 Kwh power, Indian TPPs consume as much as 80 cubic meters of
water. The water consumption in the modern TPPs in developed countries
is less than 10 cubic meters for every 1000 Kwh. The major reason
for this atrocious figure is the widespread prevalence of 'once-through
cooling systems'.
Pulp
and paper: Water consumption in Indian pulp and paper industry
is significantly higher than in developed countries:
l Complete discharge of paper machine wastewater, which can be recycled
easily.
l Use of chlorine-based bleaching technology in wood and non-wood
based mills. Due to the presence of chlorine compounds in the bleach
wastewater, it cannot be used as 'black liquor' for energy generation
and hence is discharged.
Textiles:
The textile industry in India guzzles double the accepted amount for
consumption.Why is this so? A major factor is obsolete technology
which permits minimum recycling and reuse of process water. For instance,
most textile mills in India do not use counter-current washing systems;
instead they use clean water at every stage of the wash cycle. Similarly
the reuse of final rinse water from dyeing for dye bath make-up or
reuse of soaper wastewater, is absent in most mills.
| Comparatively
very poor: Indian industry vs Global best |
| Sector
|
Average
water consumption in Indian industry |
Globally
best |
| Thermal
power plant |
On an average 80 m3/ mwh(1)
|
Less
than 10 m3/mwh(2) |
| Textiles
|
200-250
m3/ tonne cotton cloth(3) |
Less
than 100 m3/ tonne cotton cloth(2) |
| Pulp
& Paper |
-
Wood based mills: 150 - 200 m3 / tonne(3)
- Waste
paper based mills: 75 -100 m3/ tonne(3)
|
- Wood
based mills: 50 - 75 m3 / tonne(4)
-
Waste paper based mills: 10-25 m3/tonne(4)
|
| Integrated
Iron & steel plant |
10-80
m3 per tonne of finished product (average |
5
-10 m3 per tonne of finished product. Best
is around 25 m3)(practice - less than 0.1 m3 wastewater per
tonne finished product(5)
|
| Distilleries
|
75-200
m3/ tonne alcohol produced(6) |
Data
not available |
| Fertiliser
industry |
-
Nitrogenous fertiliser plant - 5.0 - 20.0 m3/ tonne(3)
- Straight
phosphatic plant - 1.4 - 2.0 m3/ tonne(3)
-
Complex fertiliser - 0.2 - 5.4 m3/ tonne(3)
|
An
effluent discharge of less than
1.5 m3/ tonne product as P2O5(2) |
| Source:
1. No credible data available. Estimates done by CSE from wastewater
discharge data from "Water Quality in India, Status and trends
(1990-2001), CPCB, MoEF" and annual electricity generation
data from "Annual Report (2001-2002) on the working of state
electricity boards and electricity department, Planning Commission."
2. Pollution prevention and abatement handbook, World Bank. 3.
Environmental management in selected industrial sectors - status
and need, CPCB & MoEF, February, 2003. 4. Green Rating of
Pulp and Paper Sector, CSE. 5. Integrated Pollution Prevention
and Control (IPPC), Best available techniques reference document
on the production of iron. 6. Environmental performance of Alcohol
industry in UP, UPPCB, 2000-2001. |
Iron
& Steel: The Iron & Steel sector is also water
intensive industry. In India, approximately 80-85 per cent freshwater
consumed in this sector is discharged as effluent. In contrast, in
USA over 95 per cent of the water used for steel production and processing
is recycled. Consequently, while the Indian steel companies consume
about 10-80 cubic meters water to produce a single tonne of steel,
in the US only 5-10 cubic meters of water is needed. Global best practice
for wastewater discharge in integrated iron and steel plant is less
than 0.1 cubic meter per tonne steel (See tables: Inefficient water
use...; Comparatively very poor). Indian industry will have to reduce
its voracious appetite for water. Water, the once inexhaustible natural
resource, is going to be one of the most important factors to decide
the growth and development of Indian industry in the future.
|
