Moringa Olifera - "A natural coagulant for water treatment"

In the tropics, many people use rivers as their main water source. The river water can be cloudy and very polluted, especially during the season rainy season when river sediments are removed and remain in suspension, along with runoff fields and other surfaces carrying solids, bacteria and other organisms micro element.
It is essential that purification procedures eliminate the maximum amount of suspended material, before they go to water disinfection stage. To remove the solid material used coagulants, which are added to untreated water, usually are products chemicals such as aluminum sulfate (alum) or synthetic polyelectrolytes. In countries developing these products are often imported, involves a large outlay of foreign exchange.
For many years researchers have been explore the potential of the seeds of Moringa Oleifera in water treatment, by collecting samples from containers water storage, seed treated with Moringa crushed to better sedimentation. Their findings show that the seed of Moringa Oleifera crushed, a natural coagulant could be a viable alternative to replace partially or completely alum and other products chemicals used in water treatment.
In developing countries, technologies for the water treatment should be solid, cheap and less complicated as possible. With this philosophy in mind treatment is prototype design process for the purification of river water. The plant was installed in the grounds of the Workshop Water Treatment Thyolo, Region Nsanje, in Malawi, a treatment plant controlled by the Ministry of Works and the Water Department of Government of Malawi. The pilot system was put in service in 1992 during the rainy season, in which time, levels of contamination of river water exceeded 400 NTU.(Nephelometric Units Turbidity used to measure pollution are optical measure of the amount of suspended material; in the guidance of World Health Organization, the value of drinking water in developing countries is 5 NTU).
In the pilot plant, the removal of solids was higher to 90%, consistent Fonna after a period of flocculation in a bed of gravel and sediment flat horizontal flow. A subsequent filtration with sand rapid gravity gave a final water pollution treated fairly below 5 NTU. The dose of Moringa oleifera used in the pilot plant ranged from j5, 250 mg/L-1, depending on the initial water turbidity(Folkard et al., 1993). It was also noted that, while alum performs well as a coagulant only in a restricted area of pH levels, the Moringa performs well regardless of pH water. This is an advantage for developing countries development, where they often can not be controlled in effectively the pH prior to coagulation.
In Lake Hajar, in Zimbabwe, have become recently enriched treatment studies organic material and nutrients. The lake feeds the plant primary treatment (Sutheriand et aL, 1995). The water contains much organic matter in light suspension caused by growth of algae and generally remains a bit murky during the year. Therefore, the treatment requires large amounts of alum, which is the primary coagulant. The flocculus of alum overflows the clarifiers and can clogging the filter and generate a large amount of sediments, it is also a source of contamination when discharged into water bodies. The use of Moringa oleifera combined with sodium bentonite as an agent counterweight was a quality of water equivalent to produced using alum. The sediment was much more compact and the product, instead of being an agent contaminant, works as a conditioner and soil fertilizer.

Reference:

SUTHERLAND, J.P.; FOLKARD, G.K.; AL KHALILI, R. 1995. Preliminary investigations of alternativa coagulat/floeculant dosing regimes to treat the Morton Jaffray source water. Report to Construction Associates. s.n.t. s.p.

FOLK-ARD, G.K.; SUTHERLAND, J.P.; GRANT, W.D. 1993. Natural coagulants at pilot seale. In: Piekford J., ed. Water, environtnent and management: WEDC Conference (18, 1992, Kathmandu Nepal). Proecedings. Loughborough, G.B., Loughborough University Press. p. 51-54.