Contaminant transport modelling of the vulnerability of aquifer to cyanide from cassava processing mill in the western Niger Delta

Abstract

The threat to groundwater by toxic wastewater in the vicinity of cassava processing mills has not been taken seriously in the Niger delta region. Consequently, the fate of cyanide from the surficial surface into underlying aquifers was modelled by MODFLOW and MT3DMS. The vulnerability is influenced by subsurface geology, vertical hydraulic conductivity and sorptive characteristics of the unsaturated zones, seasonal recharge and depth to water levels. The migration of cyanide is considerably not different from the direction of groundwater flow. Its migration is significantly affected by the geology and constituents of the unsaturated zones which retard the spread of cyanide plume into the underlying aquifers. The study has successfully demonstrated the effectiveness of MODFLOW and MT3DMS in determining the vulnerability of aquifers to cassava wastewater from processing mills and associated contaminants. The pumped-and- treat technique is specifically suggested for the remediation of cyanide contaminated aquifers characterized by high hydraulic conductivity.