Coffee processing involves large volumes of water and wastewater. Coffee growing estates draw water for pulping from huge natural and man-made water bodies. These water bodies in turn feed the down stream lakes or streams. Coffee effluent, which is rich in sugars, pectin, phenolics, etc, are biodegradable, contains a high BOD/COD load. Coffee effluent poses significant threat to man-made and natural lake ecosystems. An organic load of 35kg BOD/tonne of fruit processed is released to natural and man-made water bodies. The large effluent volume is resorted to because of the absence of appropriate methods to treat high strength waters as well as the high costs of treatment. If water use in processing is reduced, a thick and concentrated effluent is produced, which is difficult to treat in the conventional lagoon systems. Conventional lagoon systems often improperly operated results in only < 50% BOD removal and a load of 10-18 kg BOD/ tonne fruit is let into water bodies inadvertently. This paper proposes management of this pollution through the use of biomass immobilized bioreactors (an appropriate technology solutions) coupled to aerobic lagoons > 95% BOD is removed and < 1kg BOD enters the water bodies for every ton of fruit processed. The reduction in operating costs and gaseous fuel is an attractive bonus especially to small and medium plantations dispersed around 4 districts of Karnataka. This paper discusses results of a few field trials with bioreactor technology and pollution management.

Address: Manjunath GR & Vinutha Devi ASTRA, Indian Institute of Science, 
Bangalore-560 012. Karnataka. India.

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