Coagulation-Clarification of Coloured Water Using Natural Coagulant (Moringa oleifera)

This paper presents the progress achieved in the study of coagulation-clarification of
coloured water using a natural coagulant (Moringa oleifera). The main objective of
this project was to evaluate the efficiency of Moringa oleifera seed extract as
primary coagulant and coagulant aid in treating coloured water in Malaysia. A
number of jar tests with low turbidity (ca. 50 NTU) and medium-level true colour
condition ( ca 50 CU) with corresponding apparent colours were carried out within
the project tirneline. The model turbid water (ca. 50 NTU and 50 CU) underwent
three different tests; by using aluminium sulphate as primary coagulant, Moringa
oleifera seed extract as primary coagulant and Moringa oleifera seed extract
coagulant aid. Moringa o/eifera seed extract reduced turbidity and colour of the
river water, but it was less effective compared to aluminium sulphate. Alum (25
mgll) produced excellent clarification (filtrate turbidity: 1.72 NTU; filtrate colour:
3.0 CU), where as Moringa oleifera seed extract (500 mgll) produced acceptable
clarification (filtrate turbidity: 4.24 NTU; filtrate colour: 15.0 CU). Combination of
aluminium sulphate (15 mgll) and Moringa oleifera seed extract (80 mg/l) produced
comparable and consistent clarification (filtrate turbidity: 3.54 NTU; filtrate colour:
13.0 CU).