Evaluation of the Quality of Household Waste Leachate Treated by Settling Ponds at the Ouagadougou Waste Treatment and Valorization Center

Abstract

In African cities, today's patterns of consumption are increasingly generating solid and liquid waste. This waste requires adequate management as it poses significant risks to public health and the environment. To meet the challenge in Ouagadougou, a waste treatment and recycling center has been implemented. The leachates from household refuse evacuated in this center are treated by two series settling ponds whose performances have been evaluated throughout the present study. For this purpose, samples were taken from the basins and analyzed weekly for two months. On these samples, the physical parameters (pH, temperature, conductivity), organic pollution indicators (BOD 5 , COD, SS), nitrogen pollution (nitrate, nitrite) and phosphorus pollution (ortho-phosphates) were evaluated according to AFNOR standards. The average of suspended-matter contents above 13,000 mg/L and this particulate pollution abatement recorded is 2.04%, whereas the Chemical Oxygen Demand reached respective maximum values of 660 and 480 mg/L for both basins. Nutrients such as nitrates were well eliminated whereas orthophosphates are released. PH values varied between 8.62 and 9.51, while electrical conductivity values varied between 482 and 625 μS/cm. The Fecal Coliforms reached maximum concentrations of 10,000 and 12,800 UFC/100mL.

Urban Solid Waste Transportation, Composting, Recycling, and Landfill Issues in Subsaharian Africa Cities

“…The pH measured on the eluate of the fines from the four cities is basic (9.6 in Kara,9.5 in Ségou,and 9.8 in Koulikoro). The basic character of the leachate is confirmed by several studies where the pH measured on the leachate is 8.9 in Ouagadougou (Demakoye et al, 2017), somewhere in the range of 8.33 and 8.78 in Abidjan (Naminata et al, 2018), 10 in Yaoundé (Oben et al, 2019), 8.24 in Alexandria in Egypt (Raghab et al, 2013, somewhere in the range of 7.6 and 8.5 in Ireland (Brennan et al, 2016). The TOC content is higher than the French standard in the four cities.…”