Comparative study of the effects of Herbal and chemical Coagulants in the clarification of raw water

The use of aluminum sulphate in clarifying raw waters raises many concerns about its impact on human health. Thus, the present study was initiated to compare effects Moringa oleifera and besides evaluating association between M. or with Opuntia ficus-indica syntofloc for water treatment. essays were carried Jar Test using 352.80 Nephelometric Turbidity Units (NTU). monitoring different physico-chemical microbiological parameters at doses after decanting time used determine optimal conditions evaluate effectiveness results showed that it took fewer less than moringa obtain same residual turbidity. 0.9 g/L removed 99% turbidity 12 h decanting. Successive (0.9 g/L) O. extract (0.6 ml) reduced 15 min. However, this treatment eliminated only 57% total coliforms. moringa/cactus association, although highly effective, remains based synthofloc. This "organic" is nevertheless an ideal alternative because great capacities could be further optimized. Key words: Coagulation-flocculation, turbidity, oleifera, sulphate, Cactus.