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Cassava Processing and the Environmental Effect
1  Post-harvest/ Fabrication, IITA Ibadan

Abstract: Cassava (Manihot esculenta Crantz) is a very important food crop that is capable of providing food security. Cassava roots can be converted through processing into enough food. Processing cassava roots to other useful products normally provides assistance to farmers' efforts in reducing hunger and poverty for millions of families within urban and rural areas. Machine application for cassava roots processing has helped greatly to add value, leading to profit making and provision of food. Aside from improving farmers' income, value addition to the harvested roots addresses unemployment and turning around the fortunes of farmers within a given community.Most developing countries depend on natural resources for their energy need. The farmer at the village level depends on the sun for drying of cassava products. They obtain firewood from forests and use fossil fuel from petroleum to power the tractor and small internal combustion engine (ICE). Graters are used to disintegrate roots into mash.  A typical cassava grater consists of a wooden drum rotor of about 250 to 300 mm in diameter, covered with a perforated tin sheet and is usually powered by an electric motor or diesel/petrol engine. This saves time and is less injurious to operators. In traditional operations, fermentation and pressing (de-watering) are done in one operation. Fermentation and pressing take a long time. The common practice with mechanical presses is to use either hydraulic jacks or a bolt screw and plate ram to apply pressure to woven polyethylene sacks that contain the grated cassava mash. Gari frying and flour drying are complex procedures, which depends on the skill of the operator. The inability to control the temperature; exposure of the operator to heat and smoke from the fire; and steam from the wet cassava mash, have been major setbacks in mechanising the traditional frying of gari. Sometimes cassava roots are fermented in streams and ponds, polluting upstream of drinking water points. This paper is concerned about the effect of these activities on the environment. Waste water from cassava processing, if released directly into the environment before proper treatment, could be a source of pollution. In many areas where traditional processing is practised, waste water is normally discharged beyond the factory wall into roadside ditches or fields and allowed to flow freely, settling in shallow depressions. This will percolate into the subsoil or flow into streams. Can this type of environmental pollution be controlled? Can the foul odour lead to contamination of surface and underground water? The global weather system is threatening to spin out of control. Seasons are becoming unpredictable, farming is becoming riskier, freshwater supplies are become unreliable, and storms are raising, sea levels are threaten to take away coastal areas. Further examinations were conducted using literatures and personal observation to see if the pollution, particularly of nitrogen and phosphates (often associated with cultivations and use of mineral fertilizers) as well as carbon dioxide could be reduced or eliminated, so as to be able to sustained systems which could contribute to the reversal of global warming. From the investigation conducted fossil fuels were found to have the biggest historical and present share of polluting emissions. This contributes directly to global warming. Firewood consumption has led to severe deforestation and desertification. Cassava processing activities like any other industry have it s own share in emitting greenhouse gases that can responsible for global warming. Climate change is probably the most serious challenge that the human race has ever confronted. The level of atmospheric carbon dioxide (CO2) affect both water availability and demand, through its influence on vegetation. It is widely accepted that the increasing concentration of greenhouse gases in the atmosphere is altering the earth's radiation balance and causing the temperature to rise. Effluent water and dangerous gases produced by cassava processing centres required better handling. Attempts needed to be made to correct them were fully explained so also the use of cleaner fuel that can lower the generation of carbon dioxide in our farm machines was proposed in other to balance the resources and climate.
Keywords: Food-security; sustainability; resources; environment Global-warming; Cassava-root; processing
Comments on this paper
Oladele Peter Kolawole
cassava processing wastes
Most cassava processing wastes are not treated, but are freely disposed into the environment
causing pollution and odour problems. Household animals such as goats and sheep, and also fish, have been killed by cyanide from cassava effluents (Ohimain et al., 2013).

Ohimain, E.I.,Silas-Olu, D.I., Zipamoh, J.T., 2013. Biowastes Generation by Small Scale Cassava Processing Centres in Wilberforce Island, Bayelsa State, Nigeria. Green. J. Environ. Manage. Publ. Saf.2, 51 - 59
Oladele Peter Kolawole