Spatiotemporal assessment of the impact of olive-growing industry effluent on the Elmakhazine wadi dam in the Loukkos region (Morocco). Investigations into physicochemical, bacterial, and statistical processes

Abstract

This study's goal is to assess the spatiotemporal effects of margined effluents from the Loukkos region's olive-growing industries during four time periods in 2020–2021 on the wadi Elmakhazine dam's surface waters. The effluents from eight sampling stations upstream and downstream of the dam were subjected to physico-chemical, bacteriological, and statistical analyses to meet this goal. A spatiotemporal monitoring of the physicochemical and bacteriological parameters of dam water pollution was also done. According to the findings of this study, these parameters follow an increasing gradient from the control source upstream to the dam's downstream and are characterized by high concentrations of chemical oxygen demand (COD), suspended matter (SSM), and biological oxygen demand (BOD5). Simultaneously, spatiotemporal monitoring of bacteriological parameters reveals a slight increase in total coliforms (TC), faecal coliforms (FC), and faecal streptococci (FS)from upstream to downstream. The statistical study using the principal component analysis (PCA) shows that the results obtained of the total information are very important for the whole periods of September-October (*), November-December (**), March-April (***), and July-August (****) such as these results have registered in the order of 99.91% according to axis F1 (92.76%) and F2 (7.15%). These results confirmed the spatiotemporal variation of the results obtained from the physicochemical and bacteriological parameters.