Sinú River raw water treatment by natural coagulants

Five natural coagulants extracts in saline were evaluated: stems Hylocereus cf. trigonus (Cactus), exudate gum Albizia saman (Campano), bark Guazuma ulmifolia (Guacimo) and bark and seed of Moringa oleifera (Moringa) in raw water samples taken from the Sinu river with initial turbidity levels between 56 and 300 nephelometric turbidity units (NTU). With Jar tests, the turbidity removal efficiencies as a function of percent activity coagulant dosages applied between 5 mg/L to 200 mg/L was determined. Although the Total Organic Carbon (TOC) is an important parameter of the water quality, it was not included in this study because it has been found that the Sinu river turbidity is from sedimentary origin and its stream has a low organic load. The optimal extract dosage was found to be between 10 mg/L and 40 mg/L obtaining removal efficiencies from 40% (turbidity lower than 100 NTU) to 90% (initial turbidity higher than 150 NTU) for extracts of stems H. cf. trigonus, exudate gum A. saman, bark G. ulmifolia and bark M. oleifera. The M. oleifera seed extract had the greatest turbidity removal efficiency even when using an initial turbidity higher than 150 NTU, achieving a coagulant activity up to 98%.