Treatment of Fecal Sludge (FS) Using Combine Bio-Digestor and Stabilization Pond in a Tropical Urban Area

Treating fecal sludge prior its disposal in the environment remains a key point in ensuring the protection of the environment and public health. Raw fecal sludge from the town Bafoussam was treated using bio-digestors combined with maturation ponds and the removal efficiencies evaluated. The monitoring of physicochemical and bacteriological analysis at the inlet and outlet of the system showed that the system enables the reduction of pollutants with discharge values in conformity to the Cameroonian guidelines for wastewater effluent discharge. The following outlet concentrations and corresponding removal efficiencies were recorded; 25.63 mg/L (99.71%) for TSS, 5.46 mg/L (95.47%) for NH4 -N, 3.31 mg/L (88.44%) for TP, 227 mg/L (97.85 %) for COD and 70 mg/L (95.4 %) for BOD5, 130 CFU/100 mL (99.99%) for fecal coliforms. The algal diversity in sampled wastewater revealed a richness of 43 species suggesting that such a system could also sustain algal production. Bio-digestors performed well in removing total suspended solids and ammonia with removal especially of 96% and 76.3% respectively, whereas stabilization ponds essentially enabled the elimination of fecal coliforms and fecal streptococci with 93.77% and 87.5% removal respectively.