Ogouvidé Akpaki^1,, Gnon Baba^{1, 2}, Nitale M’BalikineKrou¹

The lack of sites for the treatment and hygienic disposal of fecal sludge in cities in developing countries contributes to the pollution of the urban environment and the spread of fecal diseases. Thus, the study examined the effect of metal and organic pollutants from faecal sludge released at the Attidjin site near homes. Indeed, this site is open air and receives the fecal sludge collected from the city of Lomé. The calculation of the COD/BOD₅, BOD₅/COD and TSS/BOD₅ ratios shows that the faecal sludge discharged at the Attidjin site is biodegradable and contains organic pollutants. The NH₄⁺ and NO₂^- levels of these sludge are also measured and reveal that these faecal sludges contain nitrogen pollutants. The assessment of inorganic pollution was also assessed by the measurements of Cu, Ni, Zn and Mn. The Mohlman index was also measured and the results showed that these sludge are in the mineralization phase because their MI < 80 mL/g. The degree and sources of contamination were determined by calculating metal and organic pollution indices: contamination factor (CF), geoaccumulation index (Igeo), global pollution index (PI) and organic pollution index (OPI). The organic pollution index is equal to 0.75; this corresponds to very high organic pollution of the site with a high contamination factor (FC > 6). The Igeo values were Class 2 for Cu and Class 3 for Zn. These values show that the site is highly contaminated with Cu and Zn with a contamination factor of 0< FC<1.The pollution load index PLI = 1 indicates the presence of these metal pollutants at the site level. The biological treatment of these faecal sludge will be the solution to mitigate the effects of this pollution flow.

Attidjin site, faecal sludge, organic pollution, metal pollution, contamination