Contribution of the Principal Component Analysis (PCA) to the evaluation of the physico-chemical pollution of raw wastewater from the city of Khenifra-Morocco

The present study aimed to characterize raw wastewater of khenifra city (morocco),to evaluate pollution in relation to the demographic and socio-economic profiles of the population connected to the network sanitation,and interpreting the results with the contribution of acp. the physico-chemical characterization of raw wastewater revealed that liquid effluents are loaded with organic matter in terms of cod (cod average = 556.02 mg/l) whether a load of 3373.94 kg/day,a bod5 (avg. = 284.55 mg/l) with a load of about 1731.20 kg /day. tss (avg. = 239.20 mg/l) whether a load of about 1457.04 kg/day,and mineral expressed in terms of electrical conductivity (avg. = 1801.61 μs/cm) with a ph of 8.13. the mean levels of total phosphorus and tkn are of the order of 94.07 mg/l and 12.17 mg/l,respectively. although these wastewater has a high organic load (bod5 /cod = 0.51 and mes/bod5 = 0.85) they have satisfactory biodegradability. the exam of ratio cod/bod5 = 2.00 highlights the good biodegradability which biological treatment seems entirely appropriate. statistical analysis of the results by principal component analysis (pca) performed on 56 individuals and 9 variables (flow rate,temperature,ec,tss,tkn,tp,cod,bod5) show the existence of a strong positive and significant correlation between the tss,bod5,cod and electrical conductivity. the factorial plan f1,axis of pollution,represents 42.44% of the variance. the second plan f2 represents only 25.24%.