A survey of water consumption and product output from ten sago factories in India
2006
A. Manickavasagan | K. Thangavel
Most of the tapioca processing units in India separate starch from slurry by employing the gravity settling method.Sedimentation in settling tanks allows the contact ofstarch with water. This process leads to fermentation in whichalcohols and organic acids are formed and polluting the environment. Wastewaterfrom tapioca processing factoriescontain high chemical oxygen demand (11,077-19, 083 mg t-1), low pH (4.33-5.60) and causes pollution. The effluentfrom tapioca industries is acidic and organic in nature, contributing biological oxygen demand in the range of 1500 to2000 g m3. Inorganic constituents like phosphate, sulphate, chloride, and several metals are also found in tracequantities. This paper explains the water consumption, product output and effluent generation in tapioca processingindustries. The average water requirement was 4.512 m3 to process 1000 kg of cassava tubers. When the tubers are usedfor starch manufacture, a product yield of 16. 7% starch, 1.6% dirty starch and 7.0% thippi were obtained, and18.6% sago, 1.8% dirty starch, 19.1 % peel and 3.9% thippi were obtained when the tubers are used for sagomanufacture. About 95 % of the consumed water is leaving the factory as effluent.
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