Magnetic coagulant based on moringa oleifera seeds extract and super paramagnetic nanoparticles: Optimization of operational conditions and reuse evaluation

Abstract

The aim of this study was the development of a new magnetic coagulant based on nano structured iron oxide functionalized by Moringa oleifera (MO) compounds present in aqueous saline extract, for water treatment, with removal of the physical-chemical indicatives parameters, turbidity, apparent color, and compounds with absorption at UV254nm (UV254nm). The nano structured iron oxide(maghemite, γ-Fe2 O3) was synthesized without organic solvents use. These nanoparticles were functionalized by the compounds present in aqueous saline MO (without oil, extracted by ethanol and hexane) extract. Tests of coagulation and flocculation were performed by using a Jar Test equipment with medium to high turbidity water (80 NTU). The magnetic coagulant achieved removals of 94.4% for turbidity, 87.5% for apparent color and 63.4% for UV254nm, with surface waters using applied magnetic field within 30 min of settling. The treatment of coagulation followed by flocculation with magnetic functionalized MO coagulant could lessen physico-chemical properties assessed with diminished sedimentation time. The coagulant used in the study can be reused without significant loss of efficiency due to possibility of magnetic separation, showing an economically viable method and low environmental impact.