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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 CLEANTECH 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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