Optimization of the design and operation of faecal sludge dewatering stations

Abstract

Population growth and urbanization have encouraged the whole world to revamp the sanitation system safely through proper BV management value chain. The objective of this paper was to estimate the potentialities of adaptation in West Africa under a Sudano-Sahelian climate of a process for the treatment of fecal sludge by unplanted drying bed as well as the practical modalities of its implemented to achieve reliable and efficient processing with this type of device. This study was carried out in Togo more precisely in the municipality of Kozah 1. Experimentally, the study is carried out on a pilot system with an area of 0.2 m². The determining parameters in the management of faecal sludge have been taken into account at the physical, chemical and microbiological level. The acceptable average organic load after 32 days of drying is 165 Kg DM/year/m² with raw sludge and biosolids having respectively the physico-chemical characteristics: 960 mgO₂/L, 384 mgO₂/L for COD; 2814 mgN/L, 1620 mgN/L for NTK; 174.4 mg P/L, 73 mgP/L for P-PO₄^3-. The volume relative humidity remaining after 32 days of regular monitoring is 12%. Microbiological germs such as E. coli, CF, SF, Salmonella, Clostridia and Listeria were the subject of this study. The rate of their elimination is respectively: 57%, 100%, 43%, 57%, 100%, 66%. These results show that the system put in place is effective.