Cassava Processing Into “Attiéké” (A West Africa Fast Food): Wastewater Quantification and Pretreatment Using Two Fermentative Additives (Saccharomyces Cerevisiae and Sodium Bicarbonate)

Abstract

The need for alternative energy sources rises steeply researches on residual agricultural biomass. Artisanal processing of agricultural products in the agri-food chains represent an essential pollution source in most emerging countries and get interest also in the energy sector. The present study final objective enables to convert wastewater from cassava processing in Attiéké, a traditional food largely consumed in West Africa, to energy in a cheapest way. To achieve the purpose, cassava processing wastewater pH and biodegradability was improved to perform an anaerobic digestion. Hence, two common fermentive and cost effective additives were used. Yeast (organic compound) and Sodium bicarbonate (inorganic compound) effect were compared at different amounts mix with the same quantity of cassava wastewater. The experiments were carried out in triplicate. The best pH result was obtained from 7g of Saccharomyces cerevisiae per liter of cassava wastewater which increased the pH from 3.83 to 4.57. While 40 g Sodium bicarbonate per liter of cassava waster, increased the pH to maximum 4.17. In anaerobic environment after 15 days, Sodium bicarbonate addition (5g, 10g, 20g and 40g) increase the carbon fraction thus the mixture biodegradability but not gas production. The best additive was found to be Saccharomyces cerevisiae in comparison to Sodium bicarbonate. Results should help when to choose a cost effective additive for cassava wastewater pretreatment prior anaerobic co-digestion of cassava wastewater.