Microbiological and Physicochemical Assessment of Cassava Mill Effluent (CME) Polluted Soil in Umuagwo Ohaji-Egbema, Imo State, Nigeria

The microbiological and physicochemical quality of cassava mill effluent (CME) polluted soil was studied. A total of six soil samples (four CME polluted and two unpolluted) were collected, processed, and analyzed for total heterotrophic bacterial count (THBC), total fungal counts (TFC), total Nitrosomonas count (TNsC), total Nitrobacter counts (TNbC), total phosphate solubilizing bacterial count (TPSBC), and total lipolytic bacterial count (TLBC). Physicochemical analyses were also carried out to determine the soil's pH, total organic carbon, moisture content, nitrate, phosphate, and cyanide concentrations. The THBC had a range of 1.3x106±2.36 cfu/g – 8.6x106±2.12 cfu/g, TFC had a range of 1.87x103±1.23 cfu/g – 4.0x103±1.62 cfu/g, TNsC had a range of 8.2x104±1.22 cfu/g - 3.2x106 ±3.86 cfu/g, TNbC had a range of 1.95x104 ±1.28 cfu/g – 1.0x106 ±1.25 cfu/g, TPSBC had a range of 2.3x105 ±1.16 cfu/g – 4.0x105±0.8 cfu/g, while TLBC had a range of 0.85x103±1.43 cfu/g – 2.2x104±1.34 cfu/g. The CME-polluted soil recorded a higher microbial population compared to the unpolluted soil samples. The physicochemical analysis revealed a more acidic pH of 6.28±0.01 – 6.57±0.06 for the polluted soil compared to the unpolluted, which had a slightly alkaline pH. This study has, however, revealed that the microbial and physicochemical quality of soils can be affected by CME pollution.