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A
large number of case studies on implementation of are sifted to
reproduce some of the significant examples to amplify the broad
features of cleantch as follows;
1.
High Costs High Returns: The case pertains to an Indo-U.S. joint
venture producing high quality bimetal bearings for use in the
automobile industry. The industry, an ISO: 9000 company, was
releasing electroplating effluent containing lead, tin and nickel
after treatment into a highly sensitive watercourse, meeting the
drinking water needs of a downstream township. They had invested
U.S.$ 500,000 to install an effluent treatment plant and were
spending another U.S. $ 40,000 annually towards its operation still
not able to satisfy the community. After a cleantech study analyzing
the material balance and the nature of effluent, many options
including membrane technology and electro-dialysis were considered.
Since the nature of effluent, which comprised of rinse water,
revealed the presence of plating chemicals only, it was decided to
install a vacuum evaporation unit, subjecting the entire effluent to
vacuum evaporation. The condensate was used back as process water
and the concentrated plating chemicals were ploughed back into the
process. The savings on chemicals recovered and treatment cost
avoided ensured a pay back of one year on an investment of the order
of U.S. $ 400,000, leaving the process truly to a zero discharge.
The effluent treatment plant was dismantled to make way for a tennis
court.
2.
Low Cost High Returns: After serious complaints of pollution of
a nearby stream, the wastewater from an apple processing industry
was analyzed to find no harmful effluents. At the same time, it was
discovered that the industry was dumping apple pomace (solid waste
after juice extraction) into the stream, causing much trouble. After
process analysis, a waste heat dryer was installed, using the waste
heat from the boiler flue, to dry the apple waste. Dry waste was
ground and sold off as ingredient for cattle feed. The total
investment involved was not in excess of U.S. $ 3000 and the savings
from the sale of the nuisance material equaled approximately 12% of
the raw material costs.
3.
Negligible Cost Good Returns: After successful implementation of
vacuum evaporation plant for reuse of recovered chemicals, many tiny
electroplating industries indicated interest in finding solutions
but were hesitant towards making heavy investment because of
financial limitation. With small number of users, scattered over a
larger geographical spread and lack of cooperation amongst
themselves, common effluent treatment concept could not also mature.
After detailed deliberation, a cascading system was devised
involving three successive rinse baths. It was decided to replenish
freshwater only in the last bath, replenishing the make up water for
the second bath from the third one and the first from the second
one, eventually meeting the replenishment of the plating tanks from
the first bath. The low cost system costing a mere investment of
U.S. $ 1000 ensured a zero discharge, saving plating chemicals worth
up to U.S. $ 4000 and avoiding treatment costs and hassles. Some
excess wastewater problems were encountered, that were controlled by
solar evaporation and minimization practices like vibrating rinse
and/or brushing while rinsing.
4.
No Costs High Returns: Then came up the case of a mushroom
processor who was the victim of political attacks on the plea of
pollution. He pleaded that his effluent comprised only the
biodegradable food waste and was willing to install any equipment
prescribed, to ward off the problem of smell. A detailed analysis of
his process revealed only two types of waste i.e., the wastewater
from the blancher and the mushroom fleshing arising out of breakage
of tender button mushroom. The company had installed surface
aeration facility for the wastewater treatment and was composting
the solid waste. After detailing many options, some of them highly
capital intensive, an innovative approach was finally taken. Water
from the blancher was tapped at source, mixed with the ‘waste’
mushroom, freshly collected and mashed. Just a little salt and
spice, and the soup was ready. It was just sent to the canning line
instantly to embark upon a new product. No investment and a
potential for up to 24% increase in turnover. A case of simple
innovation with zero investment leading to zero discharge with zero
gestation and instant payback.
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