Trace Elements Distribution in Soil Columns as affected by Cassava Effluents Application
Cassava effluent in form of wastewater obtained during the processing of “garri”, is indiscriminately released into the environment, the effect of which is not fully known on soils and groundwater. This study investigated the distribution of two trace elements (Cu and Mn) found in the effluent through soil columns. The experiment was conducted using three different soil types namely; Iwo, Apomu and Egbeda and four varying proportions of cassava effluent (0ml – Control, 6ml, 12ml and 18ml). The four varying proportions of the effluents translates to 2.74, 5.48, 8.22, 10.96 mg/l of Cu and 1.83, 3.66, 5.49, 7.32 mg/l of Mn. The soil samples were compacted to soil bulk density of 1.50g/cm3 inside 50 cm long and 15cm diameter columns. The leachates were collected every 24 hours after the start of the experiment and analyzed for Cu and Mn using the Atomic Absorption Spectrophotometer (AAS). The result shows that the total leachate concentration (in mg/l) of Cu in 7days varied from 5.54 to 10.11 for Iwo, 5.13 to 14.81 for Apomu and 9.2 to 15.31 for Egbeda as cassava effluent volume increased from 0ml to 18ml; for Mn, it varies from 0.81 to 27.93, 1.7 to 34.26 and 12.03 to 36.19 for Iwo, Apomu and Egbeda respectively. The effect of increasing cassava effluent volume on leachate concentration for both Cu and Mn was in the order: Apomu > Egbeda > Iwo. The difference in total volume (in ml) leached after 40 minutes of simulated rainfall for 0ml and 12ml effluent additions were 13.3, 10.3 and 2.2 for Iwo, Apomu and Egbeda respectively.
