Natural coagulants like moringa seeds or prickly pear cactus are added to water. Applied for the removal of turbidity and the partial removal of pathogens and color components. Positive coagulant particles attract to negatively charged turbidity particles, resulting in precipitating flocks. Settling or filtration step is required afterwards for the flock removal.
Natural materials might be locally available or might be planted specific for the water treatment. Costs are minimal.
Can be applied at the level of a household or a small group of households. Method might be advocated from a central level. Moringa trees for example are not naturally occurring in many areas but might well be cultivated.
The availability of natural coagulants depends highly on the local environment. E.g. moringa (oleifera) trees originally come from India but are widely used in many other tropic countries.
Seeds need to be dried and grinded before adding to water. Cactus not dried. Coagulants stay in water for >2 hours and can be slightly mixed. Optimal dosing depend on type of water. Containers need to be cleaned afterwards.
Users need to be aware of applying the method correctly, including enough settling time and careful pouring without mixing contaminated flocks with clean water. Some taste complaints were recorded after using natural coagulants, making people less willing to use it.
No relevant remarks for Natural coagulation.
Akvopedia - Natural coagulation / Flocculation