Physico-Chemical and Microbiological Pollution of Industrial Wastewater from Levrier Bay in Mauritania

Abstract

The objective of this study was to conduct a preliminary assessment of the potential impacts of effluents from freezing plants and fishmeal and oil factories in the Levrier Bay on the aquatic environment through physicochemical and microbiological characterization. Effluent samples from various factories were collected and characterized by pH, dissolved oxygen (DO), electrical conductivity (EC), total dissolved solids (TDS), salinity, temperature (T°), phosphate (PO4), nitrate (NO3), nitrite (NO2), biochemical oxygen demand (BOD5), total coliforms (TC), Escherichia Coli (E.C), and fecal streptococci (FS). The concentration ranges of the effluents were as follows: pH (6.75 to 8.57), DO (1.56 to 4.66 mg/l), EC (26620 to 78520 µS/cm), TDS (13.15 to 38.70 g/l), salinity (16.26 to 49.68 PSU), T° (7.67 to 32.7 °C), PO4 (0.25 to 80.6 mg/l), NO3 (1.77 to 74.03 mg/l), NO2 (0.02 to 1.84 mg/l), and BOD5 (0.5 to 7150 mg/l). TC (2.3 x 103 to 4.6 x 106 UFC/100 ml), EC (50 to 2 x 106 CFU/100 ml), and FS (3.4 x 103 to 2.3 x 107 CFU/100 ml). The evaluated characteristics of these effluents are likely to contaminate and degrade the receiving water bodies (exceeding international standards). Hence, pretreatment of the effluent discharge is indispensable.

Keywords

• mauritania
• pollution
• industrial wastewater
• physicochemical
• bacteriology
• nouadhibou
• levrier bay