Evaluation of the use of plantain starch as a natural coagulant for the removal of colour and turbidity in water for human consumption

Aim. To evaluate the effect on pH, removal of turbidity and colour, using plantain starch as a natural coagulant, extracted by wet and basic route, in a sample of synthetic water. Materials and methods. The starch was extracted by placing the pre-treated biomass in contact with water or a NaOH solution for 20 h at 18 ° C, and then separating by filtration. The efficiency in the removal of turbidity and colour was carried out using a jug test, varying the initial concentration of coagulant and the stirring rate. Results. It was found that the starch obtained by the wet route presented a higher level of turbidity reduction compared to that obtained with NaOH, reaching an efficiency of 94.6%; using 150 mg/L of coagulant and 40 rpm, and having a better performance than the synthetic coagulant aluminium sulphate (Al2(SO4)3). Conclusions. The variable evaluated with the highest linear influence is the combination of stirring rate and coagulant concentration. The use of plantain starch extracted by wet route is recommended for use in water treatment for human consumption, highlighting its nature as an advantage over Al2(SO4)3