Removal of Heavy Metals in Cassava Mill Effluents with Saccharomyces cerevisiae isolated from Palm Wine

Abstract

Nigeria is World leading producer of cassava accounting for about 20% of global output. Rudimentary equipment is used for cassava processing into several products such as high quality cassava flour by smallholders that dominate the cassava processing sector in Nigeria. The properties of the wastewater (cassava mill effluents) often exceed the limits for effluents to be discharge into the environment (land and surface water) as specified by Federal Environmental Protection Agency. Cassava mill effluents induce toxicological effects on the environment and its associated biota such as fisheries, flora and fauna as well as humans. This study evaluated the capacity of Saccharomyces cerevisiae isolated from palm wine to remove heavy metals in cassava mill effluents. The S. cerevisiae was identified using conventional microbiological techniques based on their cultural, morphological and physiological/biochemical characteristics. S. cerevisiae was inoculated into the sterile effluent and incubated for 15 days and triplicate sample were withdrawn at 5 days interval for analysis. The samples were prepared and analyzed using flame atomic adsorption spectrometry. Results showed a decline by 44.52%, 26.26%, 51.54%, 43.20% and 65.19% for copper, zinc, manganese, iron and nickel respectively. The findings of this study showed that S. cerevisiae is a potential microorganism for the remediation of heavy metals in cassava mill effluents. Keywords:

Impacts of Cassava Mill Effluents in Nigeria

“…CME is a major waste from cassava processing, an agro business in Nigeria [16][17][18][19][20][21][22][23], Cassava processing alters soil microbial characteristics (Table 2 and 3), physicochemical properties (Table 4), Heavy metals concentration (Table 5), cation and anions exchange (Table 6), soil enzymatic activity (Table 7), soil particle size, bulk density and porosity (Table 8) and lipase, and elevates urease concentration [77,82].…”

“…In Nigeria, cassava farming and processing into useful food items is a major source of livelihood to several families especially in rural areas [11,[16][17][18][19][20][21][22][23].…”

"Estimation of Saccharomyces cerevisiae Biomass Cultured in Cassava Mill Effluents"

“…Specifically, Nigeria is the largest producers of cassava in the world [4,11,12]. During the processing cassava mill effluents (waste water) is a major liquid wastes that are discharged into the soil without any form of treatment [6][7][8][9][13][14][15][16]. Thereby causing an alteration in microbial [17] and physicochemical constituents of the receiving soil over a prolong period of time [12].…”

“…Thereby causing an alteration in microbial [17] and physicochemical constituents of the receiving soil over a prolong period of time [12]. Studies have indicated that the constituents of the wastes could be improved upon when treated with Saccharomyces cerevisiae [6,13].…”

"Estimation of Potential Cassava Mill Effluents Discharged into Nigerian Environment "

“…Solid wastes are another group of wastes stream that is poorly managed in most urban and rural areas in Nigeria. Solid wastes result from several human activities including market [11,12], abattoir [13], household activities [14], agricultural processing such as oil palm processing (viz: empty fruit bunch, chaff, palm press fibre, palm kernel shell) [15][16][17][18], cassava processing (viz: cassava peels) [1,2,[19][20][21][22][23][24][25][26] among others. Solid wastes also include remain of scrap metals, plastics, woods, etc.…”