Yard-scale experiments aiming at assessing the suitability of vertical-flow constructed wetlands to dewater faecal sludge (FS) were conducted in Yaoundé (Cameroon). During 6 months, beds vegetated either with Cyperus papyrus L. or Echinochloa pyramidalis (Lam.) Hitchc. & Chase were fed under constant solids loading rates (SLR) of 100, 200 and 300 kg TS (total solids) m−2/year. Physicochemical parameters of raw FS and percolate as well as the dewatering efficiency of each bed unit were monitored weekly. Results showed that, despite the high loading rates, the beds' pollutant removal efficiencies were more than 78% for the parameters considered and were not affected by the SLR or the macrophyte types. Beds loaded at 100 kg TS m−2/year rarely clogged with an average dry matter content ≥ 30%. However at SLR ≥ 200 kg TS m−2/year, the occurrence of clogging was higher in the papyrus beds than those of E. pyramidalis. Approximately 30–40 cm/year of sludge will be accumulated in beds loaded at the lowest SLR against 50–70 cm/year at 200 kg TS m−2/year and more than 80 cm/year at 300 kg TS m−2/year. These promising findings suggest the system as adequate for further investigation at real scale for FS dewatering in the context of developing countries.

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The aim of this study was to assess on-site sanitation facilities in Yaounde on the basis of the eight proposed indicators of hygienic safety, sustainability and functionality of the Millennium Development Goals (MDG) target 7 definitions of improve sanitation. Information were collected on the design of toilet facilities, management and functionality through a semi-structured interview and observations of 602 randomly selected toilet facilities in 22 different urban settlements of Yaounde. In addition, information about education and socioeconomic status of householders, management and functionality of toilet facilities and health status of the users were collected. The results revealed several methods of excreta disposal and noted that approximately 3 % of households had no latrine and practiced open defecation. It also showed that 79% of latrines were covered at the top with concrete slabs while 69% with ground lined below floors. Households that lacked proper toilet facilities frequently suffered from orally transmitted sanitation-related diseases, with higher prevalence recorded in rainy seasons. This study recommends improvement in the management of sanitation facilities in some settlements of Yaounde in order to guarantee adequate sanitation in a healthy environment.