Assessment of the impact of cassava mill effluent (CME) on the microbial diversity, physicochemical parameters and heavy metal concentrations in the receiving soil

Abstract

Cassava mill effluent has become a major cause of environmental degradation which affects soil properties. This study revealed the impact of cassava mill effluent on microbial diversity, physicochemical parameters and heavy metal concentrations in the receiving soils collected in triplicate between April and June, 2015 from five sites in Ogwa, Edo State, Nigeria. Standard methods were used for the soil analysis. The mean heterotrophic, coliform and fungal counts ranged from 1.38 + 4.6x10 8 CFU/g to 8.90 + 5.5x10 8 CFU/g, 1.20 + 6.1x10 8 CFU/g to 9.4 + 5.6x10 8 CFU/g and 4.17 + 2.4x10 8 CFU/g to 7.90 + 2.8x10 8 CFU/g respectively (p Cu 2+ > Zn 2+ > Mn 2+ > Cr 6+ > Ni 2+ > V 2+ > Cd 2+ > Pb 2+ . The cassava mill effluent negatively affected the soil microbial diversity, physicochemical parameters and heavy metal concentrations in the impacted soils. Key words: Cassava mill effluent, Microbial diversity, Physicochemical parameters, Heavy metals, Receiving soil.