Country | Sludge type and/or treatment | Egg recovery | Presence (N = sample size) | Year of publication | Reference |
---|---|---|---|---|---|
South Africa | Treatment: sludge drying beds for 2 months | Flotation, sedimentation | 54 Taenia spp. eggs/g with 20 eggs/g viable (N = 60) | 2018 | [90] |
Senegal | Treatment: sludge drying beds for 2 months | Flotation, sedimentation | 0 eggs (N = 3) | 2018 | [90] |
Brazil | Dry matter sludge biosolids | Filtration, sedimentation, centrifugation and flotation | 4.85 helminth eggs/g; of which 0.3% Taenia spp. (N = 22) | 1997 | [116] |
Slovakia | Raw sludge, activated sludge and drained stabilised sludge | Sedimentation, centrifugation, flotation | 2.27% raw sludge, 1.14% activated sludge and 2% drained stabilised sludge (N = 276) | 2015 | [117] |
France | Anaerobically digested sludge | Modified Faust technique (flotation) | Between 2200 and 2400 Taenia spp. eggs/kg* sludge (N = 21) | 1990 | [118] |
England/Wales | / | / | Taeniid eggs in at least one sample/water authority (N = 162) | 1984 | [119] |
Morocco | 3 systems: Natural lagooning; infiltration–percolation sludge followed by sand filtration; and activated sludge plant | Applied flotation method for the analyses of biowastes | Taenia spp. eggs in natural lagooning: 2 eggs/g; in infiltration–percolation sludge: 8 eggs/g; in sand filtration: 2 eggs/g; in activated sludge: 4 eggs/g (N not indicated) | 2019 | [120] |
Mexico | Sludge from 3 systems: Conventional APT* with parallel plates; sludge blanket APT; and sand-assisted sedimentation Treatment: Lime stabilization | US EPA technique | 90% of helminth eggs destroyed (N not indicated) | 2000 | [91] |
Australia | Treatment: Chlorine, copper sulphate, slaked lime, ferric sulphate, UV light, drying, moist heat and cold | In vivo: feeding to calves | Only drying, keeping dry for 1 day in the presence of a small amount of common salt and boiling for 5 min killed the eggs (N not indicated) | 1937 | [92] |