Evaluating the performance of Moringa Oleifera as plant based coagulant for water treatment using statistical Design of Experiment (DOE) and multi–objective optimization

Abstract

Natural plant materials are cost effective and environmentally friendly; they do not produce poisonous secondary by-products and therefore cannot result to climate change. They are also locally available and readily implementable. These characteristics makes them potential alternative to aluminium sulphate in water coagulation. In this research, the potential of purified protein powder of Moringa oleifera as plant based coagulants for the treatment of turbid water was studied. The extract of Moringa Oleifera was prepared and characterized using AAS and Biochemical Analyzer and its potential as plant based coagulant was assessed by its ability to reduce to the barest minimum the level of turbidity, conductivity and total dissolved solids of turbid water with known turbidity of 55NTU, conductivity of 240S/cm and total dissolved solids of 186ppm. Statistical design of experiment using response surface methodology (RSM) was employed to conduct a laboratory batch experiment having extract dosage, treatment time and treatment temperature as the input variables with turbidity, conductivity and total dissolved solids as the response variable. Analysis of the result revealed that 92.624% reduction in turbidity, 87.755% reduction in conductivity and 85.100% reduction in total dissolved solids was achieved when 2.00ml of moringa extract was employed for a treatment time of 12.94 minutes at temperature of 400C.