ABSTRACT
Cassava (Manihot esculenta) is one of the most important food crops consumed in underdeveloped countries, particularly in tropical regions. The test microalgae used for this experiment is Coleochaete scutata and Chlorococcum sp. the objective of this research is to determine the effect of cassava mill effluent on their growth. The microalgae species were grown in a growth medium and setup for fourteen days (14). The concentrations 0% for control, 1%, 5%, 10%, 15%, 20%, 25%, were used and for each concentration and the microalgal growth responses were determined using a visible spectrophotometer at optical density 750nm. Physiochemical parameters such Temperature, Turbidity, pH, Conductivity, Chemical Oxygen Demand, Total Organic Carbon, Total Dissolved Solids and Dissolved Oxygen were analyzed using standard methods. Descriptive statistics, inferential (one way analysis of variance) ANOVA repeated measures, paired t-tests, and Tukey tests were performed using Microsoft Excel 2010 and the social sciences statistical tool SPSS20. The results revealed that t-test analysis shows a significant difference in Coleochaete scutata and Chlorococcum sp. with percentage yield of (p < .05). The growth of Coleochaete scutata was determine by different concentrations of cassava effluent, one-way ANOVA showed that 25%, 15% and 20% concentrations had highest growth followed by control, 1%, 15% and 10% concentration, which had the lowest growth. While the results for Chlorococcum . showed that, 25%. 15% and 20 % concentrations had highest growth, followed by control, 1%, 5%, and 10 concentrations, had the lowest growth. In conclusion, Chlorococcum sp. had more stimulatory effect than Coleochaete scutata thus, it can be used to remediate cassava mill effluents when cultured using high concentration of the effluent.
