Sensitivity analysis of model parameters on biochemical oxygen demand in integrated solar and hydraulic jump enhanced waste stabilization pond

The sensitivity analysis of selected parameters on biochemical oxygen demand (BOD) in the integrated solar and hydraulic jump enhanced waste stabilization pond (ISHJEWSP) was carried out by regression analysis approach. Based on empirical data, the linear relationship between the response variable, BOD, and the predictor variables of pH, temperature, algae concentration, dissolved oxygen (DO), inlet velocity, distance from inlet to the point of initiation of hydraulic jump, angle representing change in pond bed slope, and intensity of solar radiation was tested using various hypotheses at α = 5% level of significance. The test of hypotheses revealed that not all the regression coefficients can be taken as zero and that the observed t-values of predictor variables X1 (xpH), X3 (xAlgae), X4 (xDO), X6 (xHJL), X7 (), and the constant are statistically significant at α = 5%. The test on the equality of regression coefficients of the reduced model revealed that it is significant to infer that X1 (xpH), X3 (xAlgae), X4 (xDO), X6 (xHJL), and X7 () do not have the same incremental effect in determining the concentration of BOD at α = 5%. Also, the test that a subset of regression coefficients equals to zero revealed that at α = 5%, it is significant to infer that the deletion of X2 (xtemp), X5 (xv), and X8 (xI) does not adversely affect the explanatory strength of the model. The model developed gave a good multiple linear regression coefficient of correlation of 0.937 with a standard error of 5.17 at a significance level of 0.05. The good multiple linear regression coefficients of correlation obtained from the regression of algae concentration on temperature and solar radiation; pH on temperature and solar radiation revealed that temperature and solar radiation play a vital role in BOD degradation in the ISHJEWSP.