Effects of Cassava Processing Effluents on the Surrounding Soil of a Local Cassava Mill in Igbodo-Etche, Southern Nigeria

This research work investigated the effects of cassava processing effluents on the soil environment of a local cassava mill in Igbodo-Etche in Rivers State, Southern Nigeria. Experimental soil samples were collected 0-30cm bgl using a hand trowel at 0, 5 and 15m distances away from the cassava mill while soil samples collected at 100m distance away from the mill served as Control. Samples for physicochemical analysis were sun-dried and passed through 2mm sieve. Soil samples collected were analyzed for physicochemical parameters, mineral composition and Total Heterotrophic Bacteria and Fungi (THB and THF) counts. Analytical results revealed changes in pH, conductivity, salinity, temperature, and moisture at various distances from the cassava mill. Soil pH increased significantly (p<0.05) with distance, transitioning from acidic pH (4.2) at 0m from the cassava mill to nearly neutral pH (6.55) at 100m distance away from the mill. Conductivity and salinity decreased significantly with distance, indicating reduced ionic content and salinity further from the source. Organic matter content, Carbon, and Nitrogen decreased significantly (p<0.05) with distance, with the highest values at 0m sampling point. Phosphorus level was highest at 5m (30.40 mg/kg). Hydrogen cyanide was highest at 0m (9.59 µg/kg), reducing significantly with distance. THB and THF recorded highest counts 100m away from the mill. Findings from this study revealed that disposal of cassava processing effluents in the immediate environment of the mill resulted in significant effects on soil health. This therefore suggests that uncontrolled release of untreated cassava mill effluent is capable of causing changes in physicochemical and microbial properties of soil within the environment.