Effects of cassava mill effluent (CME) on bacteria diversity of soil and aquatic environments in South-South Nigeria

Abstract

The effects of cassava effluent on the bacteria diversity of Nkissa River in South-south area of Nigeria and the adjoining soil were investigated. Results obtained in soil analysis showed changes in temperature (28.6-32.6 0 C), pH (7.2-10.3) and toxicity of cassava (TOC) (24.2-41.3 mg/g). Highest values were obtained near the waste pit while control soil had the least values. Cyanogenic potential was highest near the pit. Total heterotrophic bacteria count ranged from 3.7×10 4 -6.6×10 6 CFU/g. Phosphate solubilizing bacteria count ranged from 2.2×10 2 -2.9×10 3 CFU /g. In all cases, highest values were obtained 100 m from the waste pit, followed by the control while the least was in the pit edge. The water analysis showed that dissolved oxygen (DO), biochemical oxygen demand (BOD), total suspended solids (TSS) and total dissolved solids (TDS) were adversely affected by the cassava effluent as values from the upstream were significantly (p<0.05) lower than those from the discharge point (DP) to the downstream areas (DS I and DS II). The metallic ions were not significantly affected. The cyanogenic potentials of the water samples were quite low (1.03-0.42 mg/l). Klebsiella Corynebacterium, Acinetobacter, and Morexalla species which were absent from Upstream (US), were found from the Discharge/Fallout Point (DFP) to the Downstream (DS) samples. Escherichia, Lactobacillus, Bacillus and Micrococcus species were found in all the water samples analyzed. The cassava effluent utilization test showed that Alcaligenes, Xanthomonas, Lactobacillus, Coryneabacterium and Micrococcus species are good metabolizers of the effluents indicated. However, Escherichia and Enterobacter species did not utilize the effluent at all. Results indicated adverse effects of the cassava mill effluent (CME) on soil parameters and water qualities which call for regulations on the disposal of CME to avoid environmental degradation.

The Influence of Cassava Mill Effluents on Soil Microbial Community in Akpabuyo, Cross River State, Nigeria

“…The organisms found on the soil with cassava effluent were able to survive because they could withstand high acidic conditions, thus the lower population of fungal species. The pH level of the soil determined the availability of nutrients and therefore affects the potency and physical property of the soil [24,25]. From this study, the results have clearly proven that cassava effluent has a great impact on the microbial population of the soil, hence can be detrimental to crop yield.…”