Surface water quality assessment of Wadi El Bey, Tunisia

In the present study, a surface water quality assessment of Wadi El Bey, located in the northeast of Tunisia and considered a highly polluted river, was performed to evaluate the water quality status and identify the hotspots requiring immediate intervention. A monitoring program using sampling series along Wadi El Bey was carried out during two years. The samples were analyzed in situ and at the laboratory using chromatographic analysis, multi-parameter sounds and high-resolution monitoring sensors (HRMS). The main focus was to monitor the polluted sources discharging to the Wadi. Several physicochemical parameters were assessed in this study, including pH, electrical conductivity (EC), turbidity, salinity, chemical oxygen demand (COD), biochemical oxygen demand (BOD), dry residue, suspended solids, dissolved oxygen (DO), chloride, nitrite, nitrate, phosphate, sulfate, calcium, magnesium, potassium and sodium. The obtained results confirmed the alarming water quality deterioration status at the different hotspots, characterized mainly by high concentrations of nitrates and COD. This pollution is due to the discharge of untreated and insufficient treated municipal and industrial wastewaters directly in the Wadi, increasing anthropogenic. The study reveal a significant pollution degree and water quality degradation, affecting the ecosystem integrity.