This study examines the Moringa oleifera seed (a tropical tree) as a coagulant, adsorbent and filter aid. The
plant is drought resistant and most of its parts are useful for various applications. Extracts from
the seed were investigated for coagulation, filter aid and adsorption. The coagulation potential of
M. oleifera was compared against alum and iron salts, and was used as a filter aid to enhance the
ripening of slow sand filters. Activated carbon prepared from the seed shell and solid residues after
coagulant extraction were used for the adsorption of chromium. With respect to coagulation of
turbid natural and synthetic waters, M. oleifera showed similar performance as metal salts and
was effective in a wider range of pH. The M. oleifera coagulant was found to be effective as a
coagulant aid in combination with metal salts, and improved organic removal was observed. Slow sand
filtration (SSF) studies, in combination with M. oleifera as a filter aid, indicated that during the
start-up use of filter aid, the ripening period was significantly reduced compared to SSF without filter
aid. It was observed that intermittent and short period dosing of M. oleifera was sufficient to
enhance ripening as continuous dosage resulted in excessive headloss development. Adsorption
studies for the removal of chromium were carried out in batch experiments and the effects of
adsorbent dose, contact time, initial metal concentrations, metal speciation and pH were analyzed.
Adsorption studies indicated that the seed (after coagulant extraction) achieved more than 94%
and 43% removal of Cr (III) and Cr (VI), respectively. The activated carbon from the seed shell
removed 99.9% and 83% Cr (III) and Cr (VI), respectively. The studies demonstrated that the
different applications of the bio-material can be integrated to achieve optimum utilization of the
resource both in water and wastewater treatment. Includes 24 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 860 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 11 |
| Published : | 11/01/2008 |
