FRESHWATER MICROALGAE

This study examined the effects of vinegar on the growth of two freshwater microalgae: Scenedesmus sp. and Chlamydomonas sp.. The experiment was setup in triplicates of different concentrations of vinegar ( 0% (control), 1%, 5%,10%,15%,20% and 25%) in a culture media and monitored for 14 days. The samples were analyzed every two days to monitor growth using a visible spectrophotometer at a wavelength of 750nm as well as other physicochemical parameters such as pH, conductivity, turbidity, total dissolved solids and dissolved oxygen. The results were analyzed using statistical two way analysis of variance ANOVA repeated measures, paired t-test, microsoft excel and descriptive statistics. The result showed that the growth of Scenedesmus sp. and Chlamydomonas sp. were affected by the different concentrations of vinegar with a significant difference (p<0.05) across all parameters. The control (0% vinegar) recorded the highest growth, yield and dissolved oxygen while the 10%vinegar concentration produced the lowest values, indicating that increasing acidity inhibited algal growth and photosynthetic activity. The comparative percentage yield between both species showed no significant difference (p>0.05), suggesting comparable productivity under mild acidity

This study investigated the effects of different urea concentrations on the growth of Chlorella vulgaris and Scenedsemus, two freshwater microalgae species were analyzed under laboratory conditions. The experiment involved subjecting the microalgae to varying concentration of urea (Control, 10%, 20%, 40%, 60%, 80% and 100%). Absorbance was measured using a 721-visible Spectrophotometer at 750nm. Physicochemical parameters such as pH, turbidity, dissolved oxygen, conductivity and total dissolved solids were analyzed. Data was evaluated using descriptive statistics, two way analysis of variance and t-tests analysis and was conducted in Microsoft Excel 2010. Results revealed significant variation in the growth responses of both microalgae. Chlorella vulgaris exhibited optimal growth at 20% and 40% urea concentration with lowest growth occurring at higher concentrations. Scendesmus, on the other hand had the highest growth at 20% urea concentration with extremely low growth at higher levels. This infers that Chlorella vulgaris was more tolerant to higher concentrations of urea and ammonia toxicity than Scenedesmus. All physicochemical parameters and growth showed significant differences across concentrations of urea apart from Turbidity