LARHYSS Journal
Volume 11, Numéro 1, Pages 91-100
2014-03-01

Characterization Of Treated Wastewater Reused For Agriculture In The Vegetable Farming Area Of Sebkha In Nouakchott, Mauritania

Authors : N’diaye Ad . Ould Sid’ Ahmed Ould Kankou M .

Abstract

The study assessed the microbiological and physicochemical parameters of wastewater collected between October 2011 and September 2012 from the effluent of the WWTP in vegetable farming area of Sebkha in Nouakchott. The results of physicochemical analysis presented in this work have shown those the values of pH varied from 7.3 to 8. The EC values of experimental samples varied from 1050 to 1650 μS/cm. The turbidity values of experimental samples varied from 26.5 to 51.2 NTU. Effluents from the WWTP are characterized by a maximum iron and manganese content respectively of 412 µg/L and 22 µg/L and a minimum of 210 µg/L and 4 µg/L. Effluents from the WWTP are characterized by a maximum ammonia and orthophosphates content respectively of 120 mg/L and 60 mg/L and a minimum of 10 mg/L and 13.8mg/L. The values of COD recorded at the WWTP effluent ranged from 25 mg/L and 75 mg/L. The microbiological results show that the microbial load of fecal coliforms and fecal streptococci is very important. The levels of fecal coliforms and fecal streptococci ranged respectively between 3.10^3 to 8.10^3 CFU/100 mL. The microbiological analysis revealed high concentrations of faecal coliforms and faecal streptococci, values exceeding the microbiological standards of the WHO. The application of Principal Component Analysis indicates that two groups of wastewater: a group of wastewater turbid characterized by a mineral salt, some metals and organic and inorganic matter expressed by COD and a group CFU/100 mL and from 5.10^3 to 9.10^3 of wastewater consists of very high levels of fecal loads, ammonium and phosphates.

Keywords

Characterization, wastewater, Sebkha, Nouakchott, Mauritania.