Moringa oleifera extract as green coagulant for pome treatment: preliminary studies and sludge evaluation

Abstract

There is an increasing concern over the production of huge volume of toxic sludge from the usage of inorganic conventional coagulant (alum) specifically for the treatment of palm oil mill effluent (POME). As such, there have been many research on greener coagulant in order to tackle the issue. In this study, Moringa oleifera extracted from salt (MOS) was utilised to evaluate its promising function as a coagulant. Turbidity, colour, chemical oxygen demand (COD) percentage reduction and sludge volume index (SVI) as a function of Moringa oleifera (M. oleifera) dosage, volume of MOS, types of salt and salt concentration were measured. POME treated with MOS had turbidity, colour, COD removal and SVI up to 51%, 50%, 65% and 148 mL/g, respectively under the following optimum conditions: 3 wt% MOS, 60 mL/L of MOS, and MOS extracted with 0.5 M calcium chloride (CaCl2) salt. Notably, 78% of SVI was reduced in comparison to M. oleifera seed (without extraction) and 94% lesser when compared to alum. The current research demonstrated that MOS can be applied as an alternative to conventional coagulant for POME treatment.