Combined water treatment with extract of natural Moringa oleifera Lam and synthetic coagulant

Abstract This study evaluated the efficiency of coagulation/flocculation, sedimentation and filtration processes using the combination of natural coagulant from Moringa oleifera Lam (MO) and synthetic coagulant aluminum polychloride (PAC) for water treatment. Raw water was obtained from the Pirapó River Basin, Maringá, Paraná State, Brazil. Coagulation/flocculation and sedimentation assays were carried out in a Jar Test. A two-layer rapid filter filled with sand and anthracite was used in the filtration stage. Water quality and therefore the efficiency of the process were determined by means of the analysis of physical, chemical and bacteriological parameters, including the determination of floc size and zeta potential. The utilization of MO contributed to the reduction of the required demand of synthetic coagulant PAC. The association of coagulants, with 80%/20% or 60%/40% of MO/PAC, ensured an improvement of water quality parameters, such as apparent color, turbidity and UV254nm, as well as the possibility of water production with adequate potability standard.