This article evaluates the physical-chemical parameters of Faecal Sludge (FS) as possible predictors of dewatering performances. Also, the variability of FS dewatering characteristics was assessed from different containments and in different seasons in relationship with dewatering performance. A total of 120 samples were analyzed were collected and analyzed during the rainy and dry seasons in April and July 2019, respectively to capture season variability. FS from pit latrine (PT) took longer to dewater followed mixer containments, while soak-away sludge (SO) took a relatively short time to dewater. Also, FS from PT was found to have high amount of settled solids hence high % of TS in dry cakes. Slow dewatering and turbid supernatant corresponded to high pH, Electrical conductivity and Total solids, but cake solids after dewatering were correlated with Total solids of FS. The FS dewaterability was higher for SO (DI = 0.9) and least for PT (DI = 0.3). Seasonal variability of FS dewaterability within the containments was higher for PT (DI = 0.74) and least for SO (DI = 0.5). Planning of FS treatment plants including sizing and design for effective dewatering performance, variation of physical-chemical dewatering predictors in sources and season could provide a relatively low-cost way to predict dewatering performance.
Variability of FS characteristics from different containments.
Seasonal variability of FS within the containment.
Dewaterbility potential of FS.
Variation of dewaterability potential of FS among and within containment.
The containment type and seasonal variation influenced the treatment of FS.